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23 février 2014 7 23 /02 /février /2014 10:18

Les cellules gliales sont les partenaires des neurones. Elles les assistent dans leurs diverses fonctions. La douleur chronique pourrait provenir d'un dérèglement du fonctionnement de ces cellules.

Douglas Fields

Hélène se tord la cheville en courant. Au début, elle pense que ce n'est qu'une petite entorse, que ça passera, mais la douleur ne disparaît pas. Au contraire, elle s'intensifie. Au moindre contact, elle ressent des décharges électriques dans la jambe… depuis des mois. La douleur chronique d'Hélène diffère de la douleur aiguë. Cette dernière est une sensation corporelle intense, un signal d'alarme qui limite la gravité de la blessure. Mais imaginez une douleur qui ne s'arrête jamais, même après guérison, et où le moindre contact devient insupportable.

La douleur chronique est due à un dys- fonctionnement des circuits de la douleur aiguë, qui déclenche en permanence une fausse alerte, dite neuropathique. Lorsque les signaux erronés atteignent le cerveau, la violente douleur qu'ils infligent est aussi réelle que celle causée par une blessure. Mais elle persiste et les médecins sont souvent désarmés pour la soulager.

Cellules non neuronales

Les médicaments antidouleur classi- ques sont souvent inefficaces face à ce type de douleur. En effet, ils ne ciblent que les neurones, alors que la douleur pourrait aussi être due à un dysfonctionnement des cellules non neuronales, dites gliales, localisées dans le cerveau et la moelle épinière. Les données acquises sur la façon dont la « glie » modifie l'activité neuronale offriraient des perspectives de traitement de la douleur chronique.

Rappelons que les neurones qui produisent les signaux de la douleur – ou nocicepteurs – tapissent la moelle épinière et collectent des informations sensorielles dans tout l'organisme (voir l'encadré page 11). Les corps cellulaires de ces neurones, qui représentent le premier des trois relais du circuit de la douleur, sont regroupés dans les ganglions des racines dorsales, entre les vertèbres. Chaque nocicepteur envoie une branche de son axone vers la périphérie pour surveiller une région distante du corps, tandis qu'une branche centrale pénètre dans la corne dorsale de la moelle épinière pour entrer au contact d'un neurone du deuxième relais du circuit de la douleur. Ces neurones transmettent les messages douloureux vers le troisième relais, le thalamus, puis vers le cortex cérébral.

Court-circuiter la douleur

Pour atténuer une douleur aiguë, il suffit parfois d'interrompre le flux d'informations en un point quelconque de ce circuit. Par exemple, les anesthésiques locaux endorment l'extrémité des axones aux alentours du site d'injection, ce qui empêche les cellules d'émettre des influx nerveux. L'organisme synthétise aussi des substances analgésiques naturelles : les endorphines, de petits peptides, qui agissent à différents niveaux du circuit de la douleur. Par exemple, au cours d'un accouchement sans péridurale, le corps libère des endorphines qui diminuent la transmission des signaux douloureux. Ainsi, les endorphines, les émotions et diverses hormones peuvent modifier la perception de la douleur en modulant la transmission des messages le long du circuit de la douleur.

En outre, les mécanismes et molécules susceptibles de modifier le flux des ions à travers les canaux ioniques des neurones contribuent à réguler la sensibilité des fibres sensorielles. Quand on se blesse, ces facteurs peuvent diminuer le contrôle qu'ils exercent sur les décharges neuronales, facilitant ainsi la transmission des signaux douloureux.

Mais cet état désinhibé dure parfois trop longtemps. Les nocicepteurs restent hypersensibilisés, ce qui provoque des décharges de messages douloureux, même en l'absence de stimulus extérieurs. C'est la cause principale des douleurs neuropathiques. L'augmentation de la sensibilité neuronale entraîne des sensations anormales de picotements, de brûlure, de fourmillements et d'engourdissement (la paresthésie). Le seuil de la douleur peut être atteint – comme chez Hélène – au moindre contact d'un objet tiède ou à la moindre pression.

Les travaux visant à comprendre comment les neurones du circuit de la douleur deviennent hypersensibles quand on se blesse se sont longtemps concentrés sur les dérèglements neuronaux. Ils ont montré qu'une simple décharge neuronale peut déclencher des signaux douloureux et modifier l'activité des gènes des nocicepteurs. Certains gènes régulés par l'activité neuronale codent des canaux ioniques et diverses molécules qui augmentent la sensibilité des neurones. Lors d'une lésion d'un nerf périphérique, l'intense activation des nocicepteurs sensibilise ces neurones, ce qui provoque les douleurs neuropathiques. Mais diverses équipes ont aussi révélé, grâce à des modèles animaux, que les neurones ne sont pas les seules cellules à réagir aux blessures et à libérer des substances stimulant la sensibilité neuronale ; la glie serait aussi concernée.

Les cellules gliales sont dix fois plus nombreuses que les neurones dans le cerveau et la moelle épinière. Elles n'envoient pas de signaux nerveux, mais modulent les décharges électriques des neurones proches. Elles assurent l'équilibre chimique autour des neurones : non seulement elles fournissent l'énergie indispensable à leur survie, mais elles récupèrent les neurotransmetteurs qu'ils libèrent quand ils transmettent un signal à un neurone voisin.

La glie libère parfois des neuromédiateurs pour augmenter ou inhiber la transmission des signaux neuronaux. Quand les neurones sont lésés, les cellules gliales sécrètent des facteurs de croissance qui stimulent la survie et la réparation des neurones, ainsi que des molécules qui activent les cellules du système immunitaire, chargées de combattre une éventuelle infection et d'accélérer la guérison. Pourtant, des résultats récents montrent qu'au-delà de ses effets bénéfiques, la glie peut aussi prolonger l'état de sensibilisation des neurones.

Depuis plus d'un siècle, on sait que la glie réagit quand on se blesse. En 1894, en Allemagne, le neurologue et psychiatre Franz Nissl avait remarqué qu'après une lésion d'un nerf, les cellules gliales, localisées à l'endroit où les fibres nerveuses se connectent dans la moelle épinière ou dans le cerveau, sont modifiées. Or les cellules gliales sont de trois types : les cellules microgliales, les astrocytes et les oligodendrocytes. Nissl avait noté que les cellules microgliales deviennent plus abondantes, et les astrocytes, ainsi nommés en raison de la forme étoilée de leur corps cellulaire, s'épaississent et se remplissent de faisceaux de fibres filamenteuses, ce qui consolide leur squelette cellulaire (quant aux oligodendrocytes, ils forment la gaine de myéline qui entoure les axones de certains neurones).

On pensait que les cellules gliales favorisaient la réparation des nerfs lésés, mais le mécanisme était mal compris. En outre, si une blessure – par exemple une entorse à la cheville – était infligée loin des circuits spinaux de la douleur, les astrocytes, dans la moelle épinière, devaient répondre non pas à la blessure elle-même, mais à des changements de signalisation au niveau des relais de la corne dorsale. Cette observation implique que les astrocytes et la microglie surveillent les propriétés physiologiques des nocicepteurs.

Au cours des deux dernières décennies, on a montré chez l'animal que les cellules gliales repèrent de plusieurs façons l'activité électrique des neurones : elles utilisent, par exemple, des canaux ioniques qui détectent le potassium et d'autres ions libérés par les neurones, et des récepteurs des neurotransmetteurs que les neurones sécrètent pour communiquer. Le glutamate, l'ATP (l'adénosine triphosphate, l'« énergie » des cellules) et le monoxyde d'azote sont les neurotransmetteurs le plus souvent détectés par les récepteurs des cellules gliales. Cette panoplie de détecteurs permet à la glie de surveiller l'activité électrique des circuits neuronaux dans tout l'organisme, et de réagir aux modifications physiologiques.

Neurones hypersensibles

Puis les chercheurs ont suspecté les cellules gliales d'être responsables du dysfonctionnement neuronal au niveau des relais de la douleur. Les cellules gliales surveillent les transmissions neuronales douloureuses, mais les modulent-elles aussi ? Un siècle après l'observation de Nissl, une expérience simple a révélé que les cellules gliales participent à la douleur chronique. En 1994, Stephen Meller et ses collègues, de l'Université de l'Iowa aux États-Unis, ont injecté à des rats une toxine détruisant sélectivement les astrocytes. Ils ont ensuite évalué si la sensibilité des animaux à des stimulations douloureuses était réduite. Ce n'était pas le cas, ce qui montre que les astrocytes n'interviennent sans doute pas dans la transmission de la douleur aiguë.

Mais les neurobiologistes ont alors traité des rats avec un agent irritant les fibres nerveuses, qui provoque une douleur chronique. Ceux qui avaient reçu précédemment la toxine détruisant les astrocytes n'ont pas développé de douleurs chroniques. Les astrocytes participeraient donc au déclenchement de la douleur chronique après une lésion nerveuse.

Les cellules gliales libèrent de nombreuses molécules – facteurs de croissance, neurotransmetteurs – qui augmentent la sensibilité des neurones des racines dorsales et des nocicepteurs. Ces cellules interprètent la décharge neuronale rapide et les changements neuronaux qui en résultent comme un signe de détresse des neurones. En réponse, elles libèrent des molécules qui diminuent le stress des neurones et amorcent leur réparation.

Les cytokines sont une autre classe de molécules synthétisées par les cellules gliales en réaction aux lésions neuronales. Les cytokines agissent comme des balises chimiques puissantes suivies par les cellules immunitaires jusqu'à la lésion. Comment une cellule immunitaire parvient-elle à repérer une petite écharde enfoncée dans un doigt ? Les puissantes cytokines libérées par les cellules endommagées par l'écharde signalent aux cellules immunitaires du sang et de la lymphe qu'il faut se précipiter vers le bout du doigt pour combattre l'agression et commencer la réparation. Elles entraînent aussi des changements dans le tissu et les vaisseaux sanguins locaux qui facilitent le travail des cellules immunitaires et favorisent la guérison, mais provoquent aussi rougeurs et gonflement. L'ensemble des effets collectifs de la signalisation par les cytokines correspond aux phénomènes inflammatoires.

Cet exemple montre comment les cytokines orientent les cellules immunitaires vers la blessure. Mais ce qui est encore plus impressionnant, c'est à quel point une petite écharde peut être douloureuse – une douleur disproportionnée par rapport à la lésion tissulaire. La zone qui entoure l'écharde enfle et devient sensible, bien que les cellules cutanées voisines n'aient pas été endommagées. La douleur autour d'une blessure est provoquée par les cytokines inflammatoires qui augmentent la sensibilité des fibres nociceptives. Les nocicepteurs hypersensibles, situés à proximité de la blessure, nous empêchent de toucher la région lésée.

Le double jeu des cellules gliales

Avec des modèles animaux, on a montré que, en général, ce ne sont pas les neurones mais les cellules gliales qui produisent les cytokines du système nerveux. Les cytokines peuvent rendre hypersensibles les terminaisons nerveuses proches d'une écharde logée au bout du doigt. Quand elles sont libérées par les cellules gliales dans la moelle épinière, en réponse aux signaux des nocicepteurs, elles diffusent vers les fibres nerveuses adjacentes pour les rendre elles aussi hypersensibles. Les cellules gliales sont alors très réactives et libèrent encore plus de facteurs sensibilisants et de cytokines. Mais au lieu de soulager la douleur, elles la prolongent. Dès lors, la douleur peut provenir de fibres nerveuses de la moelle épinière qui ne sont pas directement concernées.

Les réactions initiales des cellules gliales à une blessure sont essentielles à la guérison. Toutefois, si elles sont trop intenses ou durent trop longtemps, il en résulte une douleur chronique que rien ne peut enrayer. Plusieurs équipes ont décrit chez l'animal les boucles de rétroaction susceptibles de provoquer la libération prolongée de facteurs sensibilisants et de signaux inflammatoires par les cellules gliales, provoquant des douleurs neuropathiques. Elles ont réalisé des expériences pour tenter de découvrir comment inhiber ce mécanisme. Ces travaux ont rendu plus efficace l'utilisation des opioïdes, telle la morphine, dans le traitement des douleurs.

Combattre l'inflammation douloureuse

Par le passé, tous les traitements de la douleur chronique visaient à atténuer l'activité des neurones. Pourtant, la douleur ne peut pas disparaître si les cellules gliales continuent de sensibiliser les neurones. La démarche est aujourd'hui de cibler les cellules gliales dysfonctionnelles en les empêchant d'émettre les molécules qui entretiennent l'inflammation. Par exemple, Joyce DeLeo et ses collègues, de la Faculté de médecine de Dartmouth, ont montré chez l'animal qu'un agent chimique, la propentofylline, supprime l'activation des astrocytes et, par conséquent, la douleur chronique. L'antibiotique minocycline empêche les neurones et les cellules gliales de fabriquer des cytokines inflammatoires et du monoxyde d'azote, et réduit aussi la migration des cellules microgliales vers les lésions. Ce médicament pourrait prévenir l'hyperactivation des cellules gliales.

Une démarche similaire est centrée sur les récepteurs Toll-like (RTL). Ces protéines, exprimées à la surface des cellules microgliales et sensibles aux chémokines, signaux chimiques de détresse présents entre les neurones de la moelle épinière, stimulent la microglie de sorte qu'elle libère des cytokines. Linda Watkins et ses collègues, de l'Université du Colorado à Boulder, ont montré que si l'on bloque chez l'animal un sous-type particulier de récepteurs Toll-like, RTL-4, exprimé par les cellules microgliales de la moelle épinière, on atténue les douleurs neuropathiques provoquées par une lésion du nerf sciatique. La naloxone – un médicament utilisé dans le traitement des dépendances aux opioïdes – bloque aussi les réactions microgliales à l'activation des RTL-4. L. Watkins a montré chez le rat que la naloxone permet de faire régresser des douleurs neuropathiques installées de longue date.

Un autre analgésique, le cannabis, est parfois autorisé dans certaines indications médicales. Des molécules présentes dans le cannabis reproduisent les effets de substances analogues produites naturellement dans le cerveau, les endocannabinoïdes, qui régulent la transmission des signaux neuronaux. Cependant, il existe deux types de récepteurs aux endocannabinoïdes dans le cerveau et le système nerveux : les récepteurs CB1 et CB2. L'activation des récepteurs CB2 soulage la douleur, tandis que l'activation des récepteurs CB1déclenche les effets psychoactifs du cannabis. Le récepteur CB2 n'est pas seulement présent sur les neurones, il l'est aussi sur les cellules gliales. Quand les endocannabinoïdes se lient aux récepteurs CB2 des cellules microgliales, ces dernières diminuent leur signalisation inflammatoire. De récentes études chez l'animal ont montré que quand la douleur chronique se développe, le nombre de récepteurs CB2 sur les cellules microgliales augmente. Preuve que ces cellules essayent vaillamment de capturer plus d'endocannabinoïdes dans leur environnement pour soulager la douleur. Aujourd'hui, divers laboratoires pharmaceutiques travaillent sur l'identification d'agents susceptibles d'agir sur les récepteurs CB2 gliaux sans provoquer de dépendance.

Le blocage des cytokines inflammatoires à l'aide d'anti-inflammatoires tels que l'anakinra ou l'étanercept diminue aussi la douleur neuropathique. Plusieurs groupes ont montré que le fait d'ajouter des cytokines anti-inflammatoires telles les interleukines IL-10 et IL-2 atténue les douleurs neuropathiques chez l'animal, et bloque les signaux inflammatoires. Deux médicaments, la pentoxyfilline et l'AV411, inhibent l'inflammation en stimulant la production d'IL-10 par les cellules.

Certains de ces médicaments sont en phase d'essai clinique chez l'homme (voir le tableau ci-dessus), dont l'AV411, déjà utilisé dans le traitement anti-inflammatoire des accidents vasculaires cérébraux au Japon. Un essai en Australie a montré que les patients diminuent volontairement leur dose de morphine quand ils reçoivent ce médicament, signe que l'AV411 contribue à soulager leur douleur.

La morphine est l'un des plus puissants analgésiques connu à ce jour. Comme l'héroïne, l'opium et les opioïdes plus récents, tels que l'oxycodone, la morphine atténue la douleur en réduisant la communication entre neurones spinaux, ce qui limite la transmission des signaux nociceptifs. L'effet antalgique de la morphine et des autres opioïdes diminue – par un effet de tolérance – quand l'usage est prolongé, de sorte qu'il faut administrer des quantités toujours plus importantes et plus fréquentes pour obtenir les mêmes effets. Toutefois, il a été montré que cet effet de tolérance n'apparaît pas (ou peu) dans le cas des douleurs chroniques. Or on a découvert que les cellules gliales sont responsables du développement de la tolérance à l'héroïne et à la morphine. Comme n'importe quel toxicomane dépendant à l'héroïne qui cesse brutalement d'en consommer, les sujets devenus dépendants aux opioïdes, et qui arrêtent brusquement de prendre leurs médicaments, ressentent les symptômes du sevrage. Les malades deviennent hypersensibles au point qu'ils ne supportent ni le bruit ni la lumière. La similarité de ces symptômes et de l'hyperesthésie observée chez les patients atteints de douleurs neuropathiques suggère une cause commune.

La glie diminue l'effet de la morphine

En 2001, Ping Song et Zhi-Qi Zhao, de l'Institut de physiologie de Shanghaï, ont vérifié si les cellules gliales sont impliquées dans le développement de la tolérance à la morphine. Quand les chercheurs ont administré des doses répétées de morphine à des rats, ils ont observé une augmentation du nombre d'astrocytes réactifs dans la moelle épinière. Les modifications consécutives aux injections de morphine étaient identiques à celles observées dans la moelle épinière après une blessure ou au cours du développement des douleurs neuropathiques. Les chercheurs ont alors éliminé les astrocytes avec la toxine que S. Meller avait utilisée pour ralentir le développement de la douleur chronique chez les rats. La tolérance à la morphine chez ces animaux a notablement diminué, prouvant ainsi la contribution des cellules gliales.

Dès lors, de nombreux groupes de recher- che ont essayé de bloquer divers signaux entre les neurones et les cellules gliales (par exemple, en inactivant des récepteurs spécifiques des cytokines sur les cellules gliales) et testé si cela modifiait la tolérance à la morphine. Ces études, réalisées chez l'animal, ont montré que le blocage des signaux inflammatoires en provenance des cellules gliales ne change pas les sensations de douleur aiguë. En revanche, si les agents bloquants sont injectés avec de la morphine, ils diminuent la quantité de morphine nécessaire pour obtenir le même soulagement, et la durée de l'effet analgésique est doublée. La glie contrecarrerait donc l'effet analgésique de la morphine. Pour quelles raisons ?

La fonction fondamentale de la glie est de maintenir une activité équilibrée dans les circuits neuronaux. Dès lors, dans la mesure où les opioïdes atténuent la sensibilité des circuits de la douleur, les cellules gliales réagiraient en libérant des substances neuroactives qui augmentent l'excitabilité des neurones de façon à restaurer l'activité dans ces circuits. Au cours du temps, les cellules gliales augmentent progressivement la sensibilité des neurones à la douleur. L'héroïne ou les médicaments analgésiques opioïdes diminuent cette sensibilité, mais, quand on arrête d'administrer la drogue, les neurones déchargent intensément, ce qui provoque une hypersensibilité et des symptômes de manque douloureux. Dans les modèles animaux, les symptômes de manque douloureux associés à l'addiction à la morphine peuvent être considérablement atténués par des médicaments qui bloquent les cellules gliales.

En conséquence, moduler l'activité de la glie serait non seulement une des clés pour soulager la douleur chronique, mais aussi pour éviter que les personnes traitées avec des analgésiques opioïdes ne deviennent tolérantes. Les liens entre neurones, douleur et addiction ne devraient plus résister aux chercheurs qui tiennent compte des partenaires des neurones : les cellules gliales.

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15 janvier 2014 3 15 /01 /janvier /2014 08:45

Our Brains Have a Map for Numbers

It is as if there is a number line in our heads

By Emilie Reas | Tuesday, January 14, 2014 | 8

Come on. Get out of the express checkout lane! That’s way more than twelve items, lady.”

Without having to count, you can make a good guess at how many purchases the shopper in front of you is making. She may think she’s pulling a fast one, but thanks to the brain’s refined sense for quantity, she’s not fooling anyone. This ability to perceive numerosity – or number of items – does more than help prevent express lane fraud; it also builds the foundation for our arithmetic skills, the economic system and our concept of value.

Until recently, it’s remained a puzzle how the brain allows us to so quickly and accurately judge quantity. Neuroscientists believe that neural representations of most high-level cognitive concepts – for example, those involved in memory, language or decision-making – are distributed, in a relatively disorganized manner, throughout the brain. In contrast, highly organized, specialized brain regions have been identified that represent most lower-level sensory information, such as sights, sounds, or physical touch. Such areas resemble maps, in that sensory information is arranged in a logical, systematic spatial layout. Notably, this type of neural topography has only previously been observed for the basic senses, but never for a high-level cognitive function.

Researchers from the Netherlands may have discovered an exception to this rule, as reported in their recently published Science paper: a small brain area which represents numerosity along a continuous “map.” Just as we organize numbers along a mental “number line,” with one at the left, increasing in magnitude to the right, so is quantity mapped onto space in the brain. One side of this brain region responds to small numbers, the adjacent region to larger numbers, and so on, with numeric representations increasing to the far end.

To examine how the brain responds when perceiving quantities, the researchers conducted functional magnetic resonance imaging of the brain while participants viewed different numbers of dots on a screen. They included multiple versions of the task, keeping key features — like dot size, circumference and density — constant, to be certain that any effects were indeed attributable to dot quantity, rather than dot shape or size. The participants weren’t asked to judge the number of dots, to ensure that brain activity related to perceiving quantity, rather than counting. The researchers then looked for brain activity that systematically varied with the number of dots the participants viewed.

The scientists identified a region, a few centimeters wide, in the right superior parietal lobe (in the upper back part of the brain) that mapped numerosity. One edge of this patch (closer to the middle of the brain) responded maximally to small quantities, and the opposite edge (closer to the outside of the brain) responded to the largest quantities. The location and layout of this map was remarkably consistent across all eight individuals’ brains. Earlier studies reported that this same brain area in humans, and single neurons in an analogous part of the monkey brain, responded to numerosity. However, these studies had not detected this systematically organized map.

The researchers more closely examined how activity in this neural map related to the numbers and types of dots the participants viewed. They found that the parietal cortex map represented relative, not absolute, quantities. For instance, a given region might respond to two dots in one task condition, but to three in another; but across tasks, it always responded to small numbers of dots. Furthermore, the amount of cortex devoted to a given quantity varied, such that disproportionately more area represented small quantities, and less area represented large quantities. The map was more selective for smaller than larger numerosities. This system makes intuitive sense, as it corresponds with our subjective experience. It’s much easier to distinguish between one or two cookies left in the jar, than between eleven and twelve cookies. In light of these findings, this finer discrimination for smaller quantities might arise from their overrepresentation in the brain.

This isn’t the first time neuroscientists have observed maps in the brain. In fact, it’s well established that sensory and motor information, including representations of our visual surroundings, bodily space or sound frequency, is also topographically organized to subserve vision, touch, taste, smell and movement. For example, a homunculus, or “little man,” is mapped onto the brain’s motor and somatosensory cortices, such that different regions of this cortical map support movement and sensation in different body parts. The brain areas devoted to feeling the face and lips are adjacent, and the area responsible for toe movement lies next to that involved in ankle movement. This new study reveals that such maps aren’t limited to sensory and motor functions, but also exist for an abstract feature - numerosity.

Why might the brain devote a specialized map-like region to processing a higher-order cognitive concept like numerosity, but not other higher-order functions? Past research has shown that the ability to perceive quantity closely resembles our basic senses and is distinct from acquired mathematics skills. For instance, studies have shown that while arithmetic functions are language-dependent, quantity-based judgments are language-independent, and these distinct processes activate different regions of the brain. Whether you’re a math whiz or failed high school algebra, you can still readily judge, almost subconsciously, that there are about twenty books on a shelf or a few dogs running in a park. In fact, this skill has been observed in both infants and animals, indicating that it may be innate, much as hearing, seeing and touch are inherent sensory functions.

This explanation – that numerosity is an intuitive sense – may adequately account for the presence of a numerosity map in the brain. However, it’s not entirely clear from this study whether the organized brain responses were directly related to conceptualizingnumbers, or might instead reflect lower-level sensory features of the dots. Indeed, the researchers found that the numerosity map didn’t respond to digits (i.e., 1, 2, 3), raising questions over what numeric information was actually mapped. For now, we can only speculate whether this patch of cortex maps an ingrained “number sense,” visual features, or some combination of the two.

This discovery not only reveals an exception to the rule that brain maps exist exclusively for sensory features, but also raises the possibility that the brain contains maps for other abstract information. If numerosity is represented by a topographic brain system, might other higher-order concepts share a similar map-like organization? Just how many more hidden maps are lurking in our brain?

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5 décembre 2013 4 05 /12 /décembre /2013 06:10

Whether you're a casual user of social media sites like facebook and twitter or an avid online dater accessing eHarmony or Match.com, chances are you've created a personal online profile and been faced with a decision: What should you post for your profile picture? Many people post head shots or selfies, while others opt for pictures of their children, spouses, pets, or even favorite quotes or symbols. If your goal is to be perceived as attractive (and let's be honest, whose isn't?), then new research by Drew Walker and Edward Vul at the University of California, San Diego suggests your best bet is to opt for a group shot with friends.

A photo with friends conveys the fact that you are amiable and well-liked, but oddly enough that is not what makes you more appealing. Instead, the new research shows that individual faces appear more attractive when presented in a group than when presented alone — a perceptually driven phenomenon known as thecheerleader effect.

Consider the Laker girls or Dallas Cowboy Cheerleaders. To many, these women are beautiful and sexy. However, their perceived beauty is in part a visual illusion, created by the fact that cheerleaders appear as a group rather than solo operators. Any one cheerleader seems far more attractive when she is with her team than when she is alone.

This visual illusion is mediated by similar cognitive and perceptual processes that underlie other well-known visual illusions like the Ebbinghaus illusion or the moon illusion. With the Ebbinghaus illusion, a medium-sized dot appears much larger when surrounded by a field of smaller dots, but appears much smaller when surrounded by a field of larger dots. The moon illusion is the perception that the moon seems larger when it appears on the horizon than up in the sky. All of these visual illusions demonstrate that what we "see" is not always a simple or direct reflection of what is right in front of us. Instead, what we see depends on both the physical stimulus coded by our visual systems (what cognitive scientists refer to as bottom up processing), and a blend of contextual information, expectations, and prior knowledge (known as top down processing).

Walker and Vul posit that the cheerleader effect arises from the interplay of three different visuo-cognitive processes. First, whenever we view a set of objects like an array of dots or a group of faces, our visual system automatically computes general information about the entire set, including average size of group members, their average location, and even the average emotional expression on faces. Thus although the group contains many individual items, we naturally perceive those items as a set, and form our impressions on the basis of the collective whole.

In addition, the impression that we have of the group as a whole influences our perception of any one individual item. We tend to view individual members as being more like the group than they actually are. Thus when we see a face in a crowd, we tend to perceive that face as similar to the average of all the faces in that crowd.

As it turns out, we find average faces very attractive. Composite faces, which are generated by averaging individual faces together, are rated as significantly more attractive than the individual faces used to create them. According to Walker and Vul, if presenting a face in a group causes us to perceive that face as more similar to the average, we are likely to find that face more attractive.

To test this theory, Walker and Vul conducted a series of experiments in which participants rated the attractiveness of faces that appeared in a group or individually. In two of their studies, the group photographs included three male or three female faces together in the same scene. The individual portraits of each face were cropped from those group photographs. Participants rated each face twice, once when presented as part of the group photo, and once as an individual portrait, though the order of these ratings was randomized across participants. Both male and female faces were rated as more attractive when they appeared as part of a group photo than as a solo portrait.

Although these findings are consistent with a perceptual interpretation of the cheerleader effect, it is possible that people preferred the faces that appeared in a group because the group scene also conveyed critical social or emotional information. To address this possibility, another study was conducted in which the group photographs were constructed by assembling individual faces, each photographed separately, in a collective matrix. Again participants rated the attractiveness of each face both when it was part of a group and as an individual portrait. And again the faces were rated as more attractive when they appeared with other faces than when they appeared alone. Notably, the effect disappears when the group array consists of the same face multiple times, suggesting that it is indeed the averaging of many different faces that produces the effect.

Clearly a group photo is the way to go if you want to enhance your personal appeal. But how big does the group need to be? Walker and Vul reasoned that increasing group size should yield a more precise average, and that precise average should exert a greater influence on any one individual face. They thus predicted that faces that appeared in a large group would be rated as more attractive than those that appeared in a small group. To their surprise, attractiveness ratings did not differ for faces rated in groups of 4, 9, or 16. It seems that a small cadre of cronies may be enough to elevate your allure.

Although the current studies only assessed attractiveness ratings for photographs, the perceptual processes that mediate the cheerleader effect should function similarly regardless of whether you are interacting via facebook or face-to-face. These processes operate on an automatic level, are evident for inanimate and animate objects, and are difficult to override, even when we are aware that our eyes are lying to us. So whether you are dating online or in the flesh, take a page from the cheerleaders: Bring along some wingwomen (or wingmen).

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28 novembre 2013 4 28 /11 /novembre /2013 19:04

Did you make it to work on time this morning? Go ahead and thank the traffic gods, but also take a moment to thank your brain. The brain’s impressively accurate internal clock allows us to detect the passage of time, a skill essential for many critical daily functions. Without the ability to track elapsed time, our morning shower could continue indefinitely. Without that nagging feeling to remind us we’ve been driving too long, we might easily miss our exit.

But how does the brain generate this finely tuned mental clock? Neuroscientists believe that we have distinct neural systems for processing different types of time, for example, to maintain a circadian rhythm, to control the timing of fine body movements, and for conscious awareness of time passage. Until recently, most neuroscientists believed that this latter type of temporal processing – the kind that alerts you when you’ve lingered over breakfast for too long – is supported by a single brain system. However, emerging research indicates that the model of a single neural clock might be too simplistic. A new study, recently published in theJournal of Neuroscience by neuroscientists at the University of California, Irvine, reveals that the brain may in fact have a second method for sensing elapsed time. What’s more, the authors propose that this second internal clock not only works in parallel with our primary neural clock, but may even compete with it.

Past research suggested that a brain region called the striatum lies at the heart of our central inner clock, working with the brain’s surrounding cortex to integrate temporal information. For example, the striatum becomes active when people pay attention to how much time has passed, and individuals with Parkinson’s Disease, a neurodegenerative disorder that disrupts input to the striatum, have trouble telling time.

But conscious awareness of elapsed time demands that the brain not only measure time, but also keep a running memory of how much time has passed. Scientists have long known that a part of the brain called the hippocampus is critically important for remembering past experiences. They now believe that it might also play a role in remembering the passage of time. Studies recording electrical brain activity in animals have shown that neurons in the hippocampus signal particular moments in time. But the hippocampus isn’t always necessary for tracking time. Remarkably, people with damage to their hippocampus can accurately remember the passage of short time periods, but are impaired at remembering long time intervals. These findings hint that the hippocampus is important for signaling some – but not all – temporal information. If this is the case, what exactly is this time code used for, and why is it so exclusive?

In their new study, the researchers tried to unravel this mystery by training rats to discriminate between different time intervals. They then rewarded the rats with treats when they indicated, by choosing between different odors, that they could tell how much time had passed. Before some of the trials the scientists injected a chemical that temporarily inactivates the hippocampus. This allowed them to test whether a functional hippocampus is necessary to distinguish between different time intervals.

The rats with inactive hippocampi could tell the difference between vastly different time intervals (e.g., 3 versus 12 minutes) just as well as the control rats, but performed no better than chance at detecting differences between similar periods of time (e.g., 8 versus 12 minutes). This suggests that the hippocampus is important for distinguishing between similar time intervals, but isn’t needed when the intervals are very different. But oddly enough, this pattern only held up at long time periods; rats with nonfunctional hippocampi were not just normal at discriminating between similar time periods at short scales (e.g., 1 versus 1.5 minutes), but they in fact performedbetter.

So while the hippocampus does signal elapsed time, it has a very particular role in doing so. It specifically discriminates between similar time periods at long time scales – on the order of several minutes. When you can tell that you’ve been showering for 10 minutes, and not 15, you can thank your hippocampus. But when you sense the difference between 1 and 1.5 minutes, or 20 minutes and an hour, other brain regions have taken over as internal time-keeper.

While it may seem odd for the hippocampus to perform such a highly specialized function, this is perfectly consistent with what we know it does in other domains. The hippocampus is renowned for its ability to discriminate between overlapping objects or experiences – a process known as pattern separation. This study suggests it pattern separates many features of an experience, detecting subtle differences between objects, places and time periods.

The hippocampus might be oblivious to events that happen on a second-by-second scale, but we’re certainly able to track the rapid passage of these moments. Considering that the striatum is believed to track time on the order of seconds, the authors propose that the hippocampus and striatum might actually compete with one another, such that when the hippocampus is quieted, the striatum is freed to function even more effectively than usual. Although I wouldn’t advise intentionally damaging your hippocampus (you’ll develop a significantly graver problem), doing so could theoretically boost your ability to track the passage of short time periods.

But it’s unclear whether this inhibitory relationship is reciprocal or unidirectional. If the hippocampus and striatum indeed function as separate, antagonistic clocks, does the striatum suppress the hippocampus, just as the hippocampus appears to impair the striatum? Scientists know that damaging the striatum leads to a host of problems processing time. But could it also confer one particular time-telling superpower – that of distinguishing between similar long time intervals - by launching the hippocampus into high-gear? Only further research will tell.

So when you make it to work on time tomorrow, acknowledge not just one, but your multiple inner clocks, and rest easy you have a healthy hippocampus.

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23 octobre 2013 3 23 /10 /octobre /2013 08:02

Et en tant que tels nous sommes fait non seulement pour vivre ensemble mais surtout pour évoluer ensemble. Échanger nos expériences, nos erreurs et nos décisions.

Lisez cet interview de Matthew Lieberman et vous en serez convaincus.

Why We Are Wired To Connect

Scientist Matthew Lieberman uncovers the neuroscience of human connections — and the broad implications for how we live our lives

By Gareth Cook | Tuesday, October 22, 2013

When we experience social pain — a snub, a cruel word — the feeling is as real as physical pain. That finding is among those in a new book, Social, and it is part of scientist Matthew Lieberman’s case that our need to connect is as fundamental as our need for food and water. He answered questions from Mind Matters editorGareth Cook.

You argue that our need to connect socially is “powerful.” But just how powerful is it?

Different cultures have different beliefs about how important social connection and interdependence are to our lives. In the West, we like to think of ourselves as relatively immune to sway of those around us while we each pursue our personal destiny. But I think this is a story we like to tell ourselves rather than what really happens.

Across many studies of mammals, from the smallest rodents all the way to us humans, the data suggests that we are profoundly shaped by our social environment and that we suffer greatly when our social bonds are threatened or severed. When this happens in childhood it can lead to long-term health and educational problems. We may not like the fact that we are wired such that our well-being depends on our connections with others, but the facts are the facts.

What is the connection between physical pain and social pain? Why is this insight important?

Languages around the world use pain language to express social pain (“she broke my heart”, “he hurt my feelings”), but this could have all just have been a metaphor. As it turns out it is more than a metaphor – social pain is real pain.

With respect to understanding human nature, I think this finding is pretty significant. The things that cause us to feel pain are things that are evolutionary recognized as threats to our survival and the existence of social pain is a sign that evolution has treated social connection like a necessity, not a luxury. It also alters our motivational landscape. We tend to assume that people’s behavior is narrowly self-interested, focused on getting more material benefits for themselves and avoiding physical threats and the exertion of effort. But because of how social pain and pleasure are wired into our operating system, these are motivational ends in and of themselves. We don’t focus on being connected solely in order to extract money and other resources from people – being connected needs no ulterior motive.

This has major consequences for how we think about structuring our organizations and institutions. At businesses worldwide, pay for performance is just about the only incentive used to motivate employees. However, praise and an environment free from social threats are also powerful motivators. Because social pain and pleasure haven’t been a part of our theory of “who we are” we tend not to use these social motivators as much as we could.

You devote a section of your book to what you call “mindreading.” What do you mean by this, and why do you see it as so essential?

First off, I’m not referring to the ESP kind of mindreading. I mean the everyday variety that each of us use in most social interactions. We have a profound proclivity towards trying to understand the thoughts and feelings bouncing around inside the skulls of people we interact with, characters on television, and even animated shapes moving around a computer screen. Although we are far from perfect at gleaning the actual mental states of others, the fact that we can do this at all gives us an unparalleled ability to cooperate and collaborate with others – using their goals to help drive our own behavior.

The funny thing is that thinking about others’ thoughts doesn’t feel particularly different from most kinds of analytical thinking we do. Yet, fMRI research shows that there are two distinct networks that support social and non-social thinking and that as one network increases its activity the other tends to quiet down – kind of like a neural seesaw. Here’s the really fascinating thing. Whenever we finish doing some kind of non-social thinking, the network for social thinking comes back on like a reflex – almost instantly.

Why would the brain be set up to do this? We have recently found that this reflex prepares us to walk into the next moment of our lives focused on the minds behind the actions that we see from others. Evolution has placed a bet that the best thing for our brain to do in any spare moment is to get ready to see the world socially. I think that makes a major statement about the extent to which we are built to be social creatures.

One of the long-standing mysteries of psychology is the question of where the “self” comes from, and what the “self” even means. Does your research shed any light on this question?

Social psychologists have long speculated that the self is a much more social phenomenon then it intuitively feels like from the inside. There have certainly been studies over the years that are consistent with this idea, however neuroscience is bringing new data to bear that speaks directly to this idea.

There's a region of the brain called “medial prefrontal cortex” that essentially sits between your eyes. This region has been shown again and again to be activated the more a person is reflecting on themselves. It is the region that most clearly and unambiguously is associated with “self-processing.” If you think about your favorite flavor of ice-cream, precious personal memories, or consider aspects of your personality (e.g. Are you generous? Are you messy?) you are likely to recruit this brain region.

Given that we tend to think of the self as the thing that separates us from others – that allows us to know how we are different and how to walk our own path – it would be surprising if this same medial prefrontal region was involved in allowing the beliefs of others to influence our own. But this is exactly what we have seen in several studies. The more active the medial prefrontal region is when someone is trying to persuade you of something (e.g. to wear sunscreen everyday) the more likely you’ll be to change your tune and start using sunscreen regularly. Rather than being a hermetically sealed vault that separates us from others, our research suggests that the self is more of a Trojan horse, letting in the beliefs of others, under the cover of darkness and without us realizing it. This socially-influenced self helps to ensure that we’ll have the same kind of beliefs and values as those of the people around us and this is a great catalyst for social harmony.

What does this research tell us about how we should be raising our children, and what does it mean for education?
I think the most important thing is to educate our children about what we are learning about the true role of our social nature in our happiness and success in life. Intellectually, I know all about these things, but if we don't learn them as children, I'm not sure they ever really get into our guts and guide our intuitive decision-making. I think kids would love learning about how the social world works and how their brain makes that possible.

The research on the social brain also leads to direct policy implications for education. The data are clear that children learn better when they learn in order to teach someone else than when they learn in order to take a test. Learning to teach someone else is prosocial and relies on the social networks of the brain. We had no idea these networks could promote memory but now we do. We ought to be doing much more peer learning, particularly age-staggered learning. My ideal situation would be a 14 year who has trouble in the classroom being assigned to teach a 12 year old. The teacher then becomes a coach helping to teach the 12 year old and the 14 year old will reap the benefits of prosocial learning.

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16 juin 2013 7 16 /06 /juin /2013 10:45

D'innombrables réactions cellulaires doivent être coordonnées pour que le cerveau fonctionne correctement. Et pourtant, le hasard joue un rôle essentiel dans ce système parfaitement organisé.

Silvio Rizzoli, Benjamin Wilhelm et William Zhang

Nous pensons, éprouvons des sensations et des émotions, et agissons grâce aux 100 milliards de neurones qui se trouvent dans le cerveau humain. Tout comme les employés d'une grande entreprise, les neurones se partagent les tâches en fonction de leurs domaines de compétence. Ainsi, chaque neurone remplit une fonction bien définie. Mais, comme une entreprise, le cerveau ne peut fonctionner que si les différentes parties communiquent efficacement. Quels sont les mécanismes sous-jacents qui assurent cette communication ?

Les neurones transmettent les signaux sous forme d'impulsions électriques, nommées potentiels d'action. Ces derniers se propagent le long de prolongements cellulaires qui ressemblent à de longs filaments, les axones, au bout desquels se trouvent de petits bourgeonnements, les boutons ou terminaisons synaptiques. Chaque neurone est connecté à d'autres neurones par plus de 10 000 de ces points de contact. Il existe deux types de synapses qui se distinguent par le mode de transmission de l'information : les synapses électriques, relativement rares, et les synapses chimiques, beaucoup plus abondantes(voir l'encadré page 70). Dans le premier type, le signal électrique est directement transmis entre deux neurones par des points de contact entre les membranes cellulaires. Ces synapses transmettent, par exemple, l'information électrique entre les cellules du muscle cardiaque et permettent ainsi la contraction coordonnée du cœur.

Signal électrique et signal chimique

Toutefois, la plupart des neurones du corps humain présentent des synapses chimiques. Dans ces espaces interneuronaux, une fente d'à peine 20 nanomètres sépare la cellule émettrice de la cellule réceptrice. Puisque les potentiels d'action ne peuvent pas franchir cette fente, ils sont d'abord convertis en signaux chimiques sous forme de neurotransmetteurs libérés dans la synapse qui, eux, franchissent facilement l'obstacle. Avant d'être libérés par le neurone émetteur, ces neurotransmetteurs sont concentrés dans ce que l'on nomme des vésicules, de petits sacs membranaires sphériques.

Dès qu'un potentiel d'action arrive, les vésicules fusionnent avec la membrane de la terminaison du neurone présynaptique, et s'ouvrent vers la fente synaptique, où elles libèrent les neurotransmetteurs qu'elles contenaient. C'est le mécanisme d'exocytose(voir l'encadré page 66). Les petites molécules de neurotransmetteurs diffusent dans la fente et se lient à leurs récepteurs localisés dans la membrane de la cellule réceptrice, le neurone postsynaptique. Cette liaison déclenche à son tour une cascade de réactions qui reconvertit ce signal chimique en impulsion électrique ; ce potentiel d'action se propage dans ce neurone récepteur jusqu'à ses propres synapses – et tout recommence. Le signal produit au niveau du neurone récepteur inhibe ou active ce dernier selon les cas.

La fonction d'une vésicule ressemble à celle d'un facteur qui transmet des informations sous forme de lettres. Pour que le flux d'informations ne s'interrompe pas, le facteur doit acheminer chaque jour de nouveaux messages. Pour les vésicules, c'est pareil : après avoir fusionné avec la membrane plasmique et libéré leur contenu dans la fente synaptique, elles se reforment à l'intérieur du neurone par invagination de la membrane présynaptique – un processus nommé endocytose (voir l'encadré ci-dessous). Elles se remplissent à nouveau de neurotransmetteurs, prêtes à intervenir pour de nouvelles transmissions de signaux électriques.

Mais comment ces sphères arrivent-elles à destination ? Les neurobiologistes savent depuis longtemps qu'en plus des vésicules recyclées, de nouvelles vésicules sont produites dans le corps cellulaire des neurones. Celles-ci migrent le long des axones à l'aide de protéines sur de longues structures ressemblant à des rails, les microtubules. Si ces mouvements étaient connus, on ne comprenait pas comment les vésicules se déplacent dans les terminaisons synaptiques. Une des principales raisons de cette ignorance tient aux dimensions de ces petites sphères : avec un diamètre d'environ 50 nanomètres, elles sont invisibles en microscopie classique. Les chercheurs peuvent certes les observer à l'aide de la microscopie électronique, mais cette technique ne permet pas d'examiner des tissus in vivo et n'est donc pas utile pour étudier des mouvements.

Pour rendre visibles des structures aussi petites que les synapses, les biologistes utilisent la microscopie à fluorescence. Dans cette technique, on marque certains composants des tissus avec des molécules fluorescentes et on les active avec de la lumière d'une longueur d'onde définie. Les particules émettent alors une lumière et apparaissent sous le microscope comme des structures lumineuses (voir l'encadré page 69).

Toutefois, la résolution de la microscopie à fluorescence classique est limitée à quelque 200 nanomètres. Cette limitation est une conséquence de la longueur d'onde de la lumière utilisée. Plus la longueur d'onde de la lumière qui illumine l'échantillon est courte, plus la résolution de l'image est bonne. Voir des vésicules, c'est un peu comme essayer de remplir les carrés d'un papier millimétré avec un crayon gras et à mine épaisse. Quand on examine des vésicules par microscopie à fluorescence, les régions voisines de la synapse apparaissent également fluorescentes. Cette technique n'est donc pas adaptée pour suivre le mouvement précis des vésicules.

Mais au cours de ces dix dernières années, les chercheurs ont fait des grands progrès dans le domaine de la microscopie à haute résolution, nommée « nanoscopie ». Une des techniques innovantes a été développée par le physicien Stefan Hell, de l'Institut Max-Planck de chimie biophysique à Göttingen. Elle s'appelle microscopie STED (de l'anglais Stimulated Emission Depletion, c'est-à-dire déplétion par émission stimulée) et est fondée sur le principe de l'émission stimulée, déjà postulée en 1917 par Albert Einstein. L'échantillon est éclairé avec un premier rayon lumineux et un second rayon, nommé « rayon STED », est superposé. Ce dernier diminue la surface visible – tout comme une gomme enlèverait la couleur qui aurait débordé du carré du papier millimétré. La résolution du microscope est ainsi augmentée d'un facteur dix environ.

À l'aide de cette technique, nous avons même pu suivre le mouvement de vésicules isolées. Nous voulions savoir par quel chemin et à quelle vitesse ces petites sphères atteignent leur site d'ancrage sur la membrane présynaptique. En 2008, nous avons donc fait pousser des neurones issus de l'hippocampe de rats sur de minces lames de verre. Nous avons laissé les lames pendant 10 à 20 jours dans un milieu nutritif à 37 °C pour permettre aux neurones de former des connexions synaptiques. Nous avons ensuite marqué les vésicules avec un colorant fluorescent et nous les avons filmées sous un microscope-STED.

Les longues migrations des vésicules

Nous avons été surpris de constater que les sphères se déplaçaient apparemment au hasard dans la terminaison synaptique ; elles changeaient très souvent de direction(voir la figure 2). Un grand nombre des vésicules filmées, surtout celles qui se trouvaient dans le réservoir des vésicules, ne bougeaient quasiment pas, tandis que d'autres traversaient très rapidement la terminaison synaptique. Leur vitesse pouvait atteindre jusqu'à huit micromètres par seconde – une vitesse considérable étant donné que le diamètre de la synapse est d'environ un micromètre ! Cependant, comme le chemin des vésicules était aléatoire, leur déplacement net vers la membrane restait limité.

Qui plus est, nous avons remarqué que les vésicules ne bougeaient pas seulement à l'intérieur de la terminaison synaptique, mais s'échangeaient entre synapses voisines(voir l'encadré page 68). Ainsi, chaque minute, environ 60 vésicules entraient dans une terminaison et en sortaient. Le mouvement entre terminaisons ne semblait pas non plus être directionnel : les petites sphères changeaient apparemment de sens de façon aléatoire.

Beaucoup de trafic passif

Pour déterminer si les mouvements sont guidés par une simple diffusion ou suivent des « rails », comme c'est le cas pour leur transport dans l'axone, du corps cellulaire vers les synapses, nous avons utilisé des inhibiteurs spécifiques détruisant les microtubules et les filaments d'actine des neurones. De nombreuses composantes cellulaires sont transportées le long de ces protéines filamenteuses. Nous avons montré que même si les inhibiteurs réduisaient la mobilité de certaines sphères, ils ont peu modifié le trafic. Nous en avons conclu que certaines vésicules sont transportées activement, mais que la majorité se déplace par diffusion.

Si les neurotransmetteurs bougent apparemment de façon aléatoire dans les synapses, comment est-il possible que notre système nerveux transmette aussi rapidement et précisément des informations ? Est-ce que ce sont les potentiels d'action qui mettent de l'ordre dans le système ? En 2010, pour tester cette hypothèse, nous avons filmé le mouvement de vésicules pendant que nous stimulions électriquement les cellules. Pour ce faire, nous avons placé la lame de microscope avec les neurones entre deux électrodes. Dès que nous activions le courant, le champ électrique produit sur la lame déclenchait des potentiels d'action dans les neurones. Ces derniers se propageaient très rapidement dans le tissu nerveux. Nous avons observé le mouvement des vésicules pendant la stimulation, et juste après.

L'intérêt des processus aléatoires

Nous avons constaté que les vésicules n'étaient pas du tout influencées par l'arrivée des potentiels d'action : elles continuaient à se déplacer apparemment au hasard dans la vésicule synaptique ou restaient immobiles. Seules les vésicules situées à proximité immédiate de la fente synaptique fusionnaient avec la membrane présynaptique et libéraient leur contenu dans la synapse.

Étant donné la précision du fonctionnement du cerveau, on pensait que tous les processus sous-jacents étaient minutieusement contrôlés et structurés. Nos observations en microscopie STED montrent au contraire que la transmission des signaux repose sur des mécanismes aléatoires. Elle est pourtant d'une grande efficacité, car quelques vésicules synaptiques sont toujours en mouvement, c'est-à-dire qu'il y en a toujours suffisamment à proximité de la membrane présynaptique, prêtes à fusionner et à libérer leur contenu dès qu'un potentiel d'action arrive. C'est pourquoi le processus de fusion membranaire n'a pas besoin d'être contrôlé d'une façon plus rigoureuse.

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12 juin 2013 3 12 /06 /juin /2013 07:49

Managing Without Managers

In Brazil, where paternalism and the family business fiefdom still flourish, I am president of a manufacturing company that treats its 800 employees like responsible adults. Most of them—including factory workers—set their own working hours. All have access to the company books. The vast majority vote on many important corporate decisions. Everyone gets paid by the month, regardless of job description, and more than 150 of our management people set their own salaries and bonuses.

This may sound like an unconventional way to run a business, but it seems to work. Close to financial disaster in 1980, Semco is now one of Brazil’s fastest-growing companies, with a profit margin in 1988 of 10% on sales of $37 million. Our five factories produce a range of sophisticated products, including marine pumps, digital scanners, commercial dishwashers, truck filters, and mixing equipment for everything from bubble gum to rocket fuel. Our customers include Alcoa, Saab, and General Motors. We’ve built a number of cookie factories for Nabisco, Nestlé, and United Biscuits. Our multinational competitors include AMF, Worthington Industries, Mitsubishi Heavy Industries, and Carrier.

Management associations, labor unions, and the press have repeatedly named us the best company in Brazil to work for. In fact, we no longer advertise jobs. Word of mouth generates up to 300 applications for every available position. The top five managers—we call them counselors—include a former human resources director of Ford Brazil, a 15-year veteran Chrysler executive, and a man who left his job as president of a larger company to come to Semco.

When I joined the company in 1980, 27 years after my father founded it, Semco had about 100 employees, manufactured hydraulic pumps for ships, generated about $4 million in revenues, and teetered on the brink of catastrophe. All through 1981 and 1982, we ran from bank to bank looking for loans, and we fought persistent, well-founded rumors that the company was in danger of going under. We often stayed through the night reading files and searching the desk drawers of veteran executives for clues about contracts long since privately made and privately forgotten.

Most managers and outside board members agreed on two immediate needs: to professionalize and to diversify. In fact, both of these measures had been discussed for years but had never progressed beyond wishful thinking.

For two years, holding on by our fingertips, we sought licenses to manufacture other companies’ products in Brazil. We traveled constantly. I remember one day being in Oslo for breakfast, New York for lunch, Cincinnati for dinner, and San Francisco for the night. The obstacles were great. Our company lacked an international reputation—and so did our country. Brazil’s political eccentricities and draconian business regulations scared away many companies.

Still, good luck and a relentless program of beating the corporate bushes on four continents finally paid off. By 1982, we had signed seven license agreements. Our marine division—once the entire company—was now down to 60% of total sales. Moreover, the managers and directors were all professionals with no connection to the family.

With Semco back on its feet, we entered an acquisitions phase that cost millions of dollars in expenditures and millions more in losses over the next two or three years. All this growth was financed by banks at interest rates that were generally 30% above the rate of inflation, which ranged from 40% to 900% annually. There was no long-term money in Brazil at that time, so all those loans had maximum terms of 90 days. We didn’t get one cent from the government or from incentive agencies either, and we never paid out a dime in graft or bribes.

How did we do it and survive? Hard work, of course. And good luck—fundamental to all business success. But most important, I think, were the drastic changes we made in our concept of management. Without those changes, not even hard work and good luck could have pulled us through.

Semco has three fundamental values on which we base some 30 management programs. These values—democracy, profit sharing, and information—work in a complicated circle, with each dependent on the other two. If we eliminated one, the others would be meaningless. Our corporate structure, employee freedoms, union relations, factory size limitations—all are products of our commitment to these principles.

It’s never easy to transplant management programs from one company to another. In South America, it’s axiomatic that our structure and style cannot be duplicated. Semco is either too small, too big, too far away, too young, too old, or too obnoxious.

We may also be too specialized. We do cellular manufacturing of technologically sophisticated products, and we work at the high end on quality and price. So our critics may be right. Perhaps nothing we’ve done can be a blueprint for anyone else. Still, in an industrial world whose methods show obvious signs of exhaustion, the merit of sharing experience is to encourage experiment and to plant the seeds of conceptual change. So, what the hell.

Participatory Hot Air

The first of Semco’s three values is democracy, or employee involvement. Clearly, workers who control their working conditions are going to be happier than workers who don’t. Just as clearly, there is no contest between the company that buys the grudging compliance of its work force and the company that enjoys the enterprising participation of its employees.

But about 90% of the time, participatory management is just hot air. Not that intentions aren’t good. It’s just that implementing employee involvement is so complex, so difficult, and, not uncommonly, so frustrating that it is easier to talk about than to do.

We found four big obstacles to effective participatory management: size, hierarchy, lack of motivation, and ignorance. In an immense production unit, people feel tiny, nameless, and incapable of exerting influence on the way work is done or on the final profit made. This sense of helplessness is underlined by managers who, jealous of their power and prerogatives, refuse to let subordinates make any decisions for themselves—sometimes even about going to the bathroom. But even if size and hierarchy can be overcome, why should workers care about productivity and company profits? Moreover, even if you can get them to care, how can they tell when they’re doing the right thing?

As Antony Jay pointed out back in the 1950s in Corporation Man, human beings weren’t designed to work in big groups. Until recently, our ancestors were hunters and gatherers. For more than five million years, they refined their ability to work in groups of no more than about a dozen people. Then along comes the industrial revolution, and suddenly workers are trying to function efficiently in factories that employ hundreds and even thousands. Organizing those hundreds into teams of about ten members each may help some, but there’s still a limit to how many small teams can work well together. At Semco, we’ve found the most effective production unit consists of about 150 people. The exact number is open to argument, but it’s clear that several thousand people in one facility makes individual involvement an illusion.

When we made the decision to keep our units small, we immediately focused on one facility that had more than 300 people. The unit manufactured commercial food-service equipment—slicers, scales, meat grinders, mixers—and used an MRP II system hooked up to an IBM mainframe with dozens of terminals all over the plant. Paperwork often took two days to make its way from one end of the factory to the other. Excess inventories, late delivery, and quality problems were common. We had tried various worker participation programs, quality circles, kanban systems, and motivation schemes, all of which got off to great starts but lost their momentum within months. The whole thing was just too damn big and complex; there were too many managers in too many layers holding too many meetings. So we decided to break up the facility into three separate plants.

To begin with, we kept all three in the same building but separated everything we could—entrances, receiving docks, inventories, telephones, as well as certain auxiliary functions like personnel, management information systems, and internal controls. We also scrapped the mainframe in favor of three independent, PC-based systems.

The first effect of the breakup was a rise in costs due to duplication of effort and a loss in economies of scale. Unfortunately, balance sheets chalk up items like these as liabilities, all with dollar figures attached, and there’s nothing at first to list on the asset side but airy stuff like “heightened involvement” and “a sense of belonging.” Yet the longer-term results exceeded our expectations.

Within a year, sales doubled; inventories fell from 136 days to 46; we unveiled eight new products that had been stalled in R&D for two years; and overall quality improved to the point that a one-third rejection rate on federally inspected scales dropped to less than 1%. Increased productivity let us reduce the work force by 32% through attrition and retirement incentives.

I don’t claim that size reduction alone accomplished all this, just that size reduction is essential for putting employees in touch with one another so they can coordinate their work. The kind of distance we want to eliminate comes from having too many people in one place, but it also comes from having a pyramidal hierarchy.

Pyramids and Circles

The organizational pyramid is the cause of much corporate evil because the tip is too far from the base. Pyramids emphasize power, promote insecurity, distort communications, hobble interaction, and make it very difficult for the people who plan and the people who execute to move in the same direction. So Semco designed an organizational circle. Its greatest advantage is to reduce management levels to three—one corporate level and two operating levels at the manufacturing units.

It consists of three concentric circles. One tiny, central circle contains the five people who integrate the company’s movements. These are the counselors I mentioned before. I’m one of them, and except for a couple of legal documents that call me president, counselor is the only title I use. A second, larger circle contains the heads of the eight divisions—we call them partners. Finally, a third, huge circle holds all the other employees. Most of them are the people we call associates; they do the research, design, sales, and manufacturing work and have no one reporting to them on a regular basis. But some of them are the permanent and temporary team and task leaders we call coordinators. We have counselors, partners, coordinators, and associates. That’s four titles and three management layers.

The linchpins of the system are the coordinators, a group that includes everyone formerly called foreman, supervisor, manager, head, or chief. The only people who report to coordinators are associates. No coordinator reports to another coordinator—that feature of the system is what ensures the reduction in management layers.

Like anyone else, we value leadership, but it’s not the only thing we value. In marine pumps, for example, we have an applications engineer who can look at the layout of a ship and then focus on one particular pump and say, “That pump will fail if you take this thing north of the Arctic Circle.” He makes a lot more money than the person who manages his unit. We can change the manager, but this guy knows what kind of pump will work in the Arctic, and that’s worth more. Associates often make higher salaries than coordinators and partners, and they can increase their status and compensation without entering the “management” line.

Managers and the status and money they enjoy—in a word, hierarchy—are the single biggest obstacle to participatory management. We had to get the managers out of the way of democratic decision making, and our circular system does that pretty well.

But we go further. We don’t hire or promote people until they’ve been interviewed and accepted by all their future subordinates. Twice a year, subordinates evaluate managers. Also twice a year, everyone in the company anonymously fills out a questionnaire about company credibility and top management competence. Among other things, we ask our employees what it would take to make them quit or go on strike.

We insist on making important decisions collegially, and certain decisions are made by a company-wide vote. Several years ago, for example, we needed a bigger plant for our marine division, which makes pumps, compressors, and ship propellers. Real estate agents looked for months and found nothing. So we asked the employees themselves to help, and over the first weekend they found three factories for sale, all of them nearby. We closed up shop for a day, piled everyone into buses, and drove out to inspect the three buildings. Then the workers voted—and they chose a plant the counselors didn’t really want. It was an interesting situation—one that tested our commitment to participatory management.

The building stands across the street from a Caterpillar plant that’s one of the most frequently struck factories in Brazil. With two tough unions of our own, we weren’t looking forward to front-row seats for every labor dispute that came along. But we accepted the employees’ decision because we believe that in the long run, letting people participate in the decisions that affect their lives will have a positive effect on employee motivation and morale.

We bought the building and moved in. The workers designed the layout for a flexible manufacturing system, and they hired one of Brazil’s foremost artists to paint the whole thing, inside and out, including the machinery. That plant really belongs to its employees. I feel like a guest every time I walk in.

I don’t mind. The division’s productivity, in dollars per year per employee, has jumped from $14,200 in 1984—the year we moved—to $37,500 in 1988, and for 1989 the goal is $50,000. Over the same period, market share went from 54% to 62%.

Employees also outvoted me on the acquisition of a company that I’m still sure we should have bought. But they felt we weren’t ready to digest it, and I lost the vote. In a case like that, the credibility of our management system is at stake. Employee involvement must be real, even when it makes management uneasy. Anyway, what is the future of an acquisition if the people who have to operate it don’t believe it’s workable?

Hiring Adults

We have other ways of combating hierarchy too. Most of our programs are based on the notion of giving employees control over their own lives. In a word, we hire adults, and then we treat them like adults.

Think about that. Outside the factory, workers are men and women who elect governments, serve in the army, lead community projects, raise and educate families, and make decisions every day about the future. Friends solicit their advice. Salespeople court them. Children and grandchildren look up to them for their wisdom and experience. But the moment they walk into the factory, the company transforms them into adolescents. They have to wear badges and name tags, arrive at a certain time, stand in line to punch the clock or eat their lunch, get permission to go to the bathroom, give lengthy explanations every time they’re five minutes late, and follow instructions without asking a lot of questions.

One of my first moves when I took control of Semco was to abolish norms, manuals, rules, and regulations. Everyone knows you can’t run a large organization without regulations, but everyone also knows that most regulations are poppycock. They rarely solve problems. On the contrary, there is usually some obscure corner of the rule book that justifies the worst silliness people can think up. Common sense is a riskier tactic because it requires personal responsibility.

It’s also true that common sense requires just a touch of civil disobedience every time someone calls attention to something that’s not working. We had to free the Thoreaus and the Tom Paines in the factory and recognize that civil disobedience was not an early sign of revolution but a clear indication of common sense at work.

So we replaced all the nitpicking regulations with the rule of common sense and put our employees in the demanding position of using their own judgment.

We have no dress code, for example. The idea that personal appearance is important in a job—any job—is baloney. We’ve all heard that salespeople, receptionists, and service reps are the company’s calling cards, but in fact how utterly silly that is. A company that needs business suits to prove its seriousness probably lacks more meaningful proof. And what customer has ever canceled an order because the receptionist was wearing jeans instead of a dress? Women and men look best when they feel good. IBM is not a great company because its salespeople dress to the special standard that Thomas Watson set. It’s a great company that also happens to have this quirk.

We also scrapped the complex company rules about travel expenses—what sorts of accommodations people were entitled to, whether we’d pay for a theater ticket, whether a free call home meant five minutes or ten. We used to spend a lot of time discussing stuff like that. Now we base everything on common sense. Some people stay in four-star hotels and some live like spartans. Some people spend $200 a day while others get by on $125. Or so I suppose. No one checks expenses, so there is no way of knowing. The point is, we don’t care. If we can’t trust people with our money and their judgment, we sure as hell shouldn’t be sending them overseas to do business in our name.

We have done away with security searches, storeroom padlocks, and audits of the petty-cash accounts of veteran employees. Not that we wouldn’t prosecute a genuinely criminal violation of our trust. We just refuse to humiliate 97% of the work force to get our hands on the occasional thief or two-bit embezzler.

We encourage—we practically insist on—job rotation every two to five years to prevent boredom. We try hard to provide job security, and for people over 50 or who’ve been with the company for more than three years, dismissal procedures are extra complicated.

On the more experimental side, we have a program for entry-level management trainees called Lost in Space, whereby we hire a couple of people every year who have no job description at all. A “godfather” looks after them, and for one year they can do anything they like, as long as they try at least 12 different areas or units.

By the same logic that governs our other employee programs, we also have eliminated time clocks. People come and go according to their own schedules—even on the factory floor. I admit this idea is hard to swallow; most manufacturers are not ready for factory-floor flextime. But our reasoning was simple.

First, we use cellular manufacturing systems. At our food-processing equipment plant, for example, one cell makes only slicers, another makes scales, another makes mixers, and so forth. Each cell is self-contained, so products—and their problems—are segregated from each other.

Second, we assumed that all our employees were trustworthy adults. We couldn’t believe they would come to work day after day and sit on their hands because no one else was there. Pretty soon, we figured, they would start coordinating their work hours with their coworkers.

And that’s exactly what happened, only more so. For example, one man wanted to start at 7 a.m., but because the forklift operator didn’t come until 8, he couldn’t get his parts. So a general discussion arose, and the upshot was that now everyone knows how to operate a forklift. In fact, most people now can do several jobs. The union has never objected because the initiative came from the workers themselves. It was their idea.

Moreover, the people on the factory floor set the schedule, and if they say that this month they will build 48 commercial dishwashers, then we can go play tennis, because 48 is what they’ll build.

In one case, one group decided to make 220 meat slicers. By the end of the month, it had finished the slicers as scheduled—except that even after repeated phone calls, the supplier still hadn’t produced the motors. So two employees drove over and talked to the supplier and managed to get delivery at the end of that day, the 31st. Then they stayed all night, the whole work force, and finished the lot at 4:45 the next morning.

When we introduced flexible hours, we decided to hold regular follow-up meetings to track problems and decide how to deal with abuses and production interruptions. That was years ago, and we haven’t yet held the first meeting.

Hunting the Woolly Mammoth

What makes our people behave this way? As Antony Jay points out, corporate man is a very recent animal. At Semco, we try to respect the hunter that dominated the first 99.9% of the history of our species. If you had to kill a mammoth or do without supper, there was no time to draw up an organization chart, assign tasks, or delegate authority. Basically, the person who saw the mammoth from farthest away was the Official Sighter, the one who ran fastest was the Head Runner, whoever threw the most accurate spear was the Grand Marksman, and the person all others respected most and listened to was the Chief. That’s all there was to it. Distributing little charts to produce an appearance of order would have been a waste of time. It still is.

What I’m saying is, put ten people together, don’t appoint a leader, and you can be sure that one will emerge. So will a sighter, a runner, and whatever else the group needs. We form the groups, but they find their own leaders. That’s not a lack of structure, that’s just a lack of structure imposed from above.

But getting back to that mammoth, why was it that all the members of the group were so eager to do their share of the work—sighting, running, spearing, chiefing—and to stand aside when someone else could do it better? Because they all got to eat the thing once it was killed and cooked. What mattered was results, not status.

Corporate profit is today’s mammoth meat. And though there is a widespread view that profit sharing is some kind of socialist infection, it seems to me that few motivational tools are more capitalist. Everyone agrees that profits should belong to those who risk their capital, that entrepreneurial behavior deserves reward, that the creation of wealth should enrich the creator. Well, depending on how you define capital and risk, all these truisms can apply as much to workers as to shareholders.

Still, many profit-sharing programs are failures, and we think we know why. Profit sharing won’t motivate employees if they see it as just another management gimmick, if the company makes it difficult for them to see how their own work is related to profits and to understand how those profits are divided.

In Semco’s case, each division has a separate profit-sharing program. Twice a year, we calculate 23% of after-tax profit on each division income statement and give a check to three employees who’ve been elected by the workers in their division. These three invest the money until the unit can meet and decide—by simple majority vote—what they want to do with it. In most units, that’s turned out to be an equal distribution. If a unit has 150 workers, the total is divided by 150 and handed out. It’s that simple. The guy who sweeps the floor gets just as much as the division partner.

One division chose to use the money as a fund to lend out for housing construction. It was a pretty close vote, and the workers may change their minds next year. In the meantime, some of them have already received loans and have begun to build themselves houses. In any case, the employees do what they want with the money. The counselors stay out of it.

Semco’s experience has convinced me that profit sharing has an excellent chance of working when it crowns a broad program of employee participation, when the profit-sharing criteria are so clear and simple that the least-gifted employee can understand them, and perhaps most important, when employees have monthly access to the company’s vital statistics—costs, overhead, sales, payroll, taxes, profits.

Transparency

Lots of things contribute to a successful profit-sharing program: low employee turnover, competitive pay, absence of paternalism, refusal to give consolation prizes when profits are down, frequent (quarterly or semiannual) profit distribution, and plenty of opportunity for employees to question the management decisions that affect future profits. But nothing matters more than those vital statistics—short, frank, frequent reports on how the company is doing. Complete transparency. No hocus-pocus, no hanky-panky, no simplifications.

On the contrary, all Semco employees attend classes to learn how to read and understand the numbers, and it’s one of their unions that teaches the course. Every month, each employee gets a balance sheet, a profit-and-loss analysis, and a cash-flow statement for his or her division. The reports contain about 70 line items (more, incidentally, than we use to run the company, but we don’t want anyone to think we’re withholding information).

Many of our executives were alarmed by the decision to share monthly financial results with all employees. They were afraid workers would want to know everything, like how much we pay executives. When we held the first large meeting to discuss these financial reports with the factory committees and the leaders of the metalworkers’ union, the first question we got was, “How much do division managers make?” We told them. They gasped. Ever since, the factory workers have called them “maharaja.”

But so what? If executives are embarrassed by their salaries, that probably means they aren’t earning them. Confidential payrolls are for those who cannot look themselves in the mirror and say with conviction, “I live in a capitalist system that remunerates on a geometric scale. I spent years in school, I have years of experience, I am capable and dedicated and intelligent. I deserve what I get.”

I believe that the courage to show the real numbers will always have positive consequences over the long term. On the other hand, we can show only the numbers we bother to put together, and there aren’t as many as there used to be. In my view, only the big numbers matter. But Semco’s accounting people keep telling me that since the only way to get the big numbers is to add up the small ones, producing a budget or report that includes every tiny detail would require no extra effort. This is an expensive fallacy and a difficult one to eradicate.

A few years ago, the U.S. president of Allis-Chalmers paid Semco a visit. At the end of his factory tour, he leafed through our monthly reports and budgets. At that time, we had our numbers ready on the fifth working day of every month in super-organized folders, and were those numbers comprehensive! On page 67, chart 112.6, for example, you could see how much coffee the workers in Light Manufacturing III had consumed the month before. The man said he was surprised to find such efficiency in a Brazilian company. In fact, he was so impressed that he asked his Brazilian subsidiary, an organization many times our size, to install a similar system there.

For months, we strolled around like peacocks, telling anyone who cared to listen that our budget system was state-of-the-art and that the president of a Big American Company had ordered his people to copy it. But soon we began to realize two things. First, our expenses were always too high, and they never came down because the accounting department was full of overpaid clerks who did nothing but compile them. Second, there were so damn many numbers inside the folder that almost none of our managers read them. In fact, we knew less about the company then, with all that information, than we do now without it.

Today we have a simple accounting system providing limited but relevant information that we can grasp and act on quickly. We pared 400 cost centers down to 50. We beheaded hundreds of classifications and dozens of accounting lines. Finally, we can see the company through the haze.

(As for Allis-Chalmers, I don’t know whether it ever adopted our old system in all its terrible completeness, but I hope not. A few years later, it began to suffer severe financial difficulties and eventually lost so much market share and money that it was broken up and sold. I’d hate to think it was our fault.)

In preparing budgets, we believe that the flexibility to change the budget continually is much more important than the detailed consistency of the initial numbers. We also believe in the importance of comparing expectations with results. Naturally, we compare monthly reports with the budget. But we go one step further. At month’s end, the coordinators in each area make guesses about unit receipts, profit margins, and expenses. When the official numbers come out a few days later, top managers compare them with the guesses to judge how well the coordinators understand their areas.

What matters in budgets as well as in reports is that the numbers be few and important and that people treat them with something approaching passion. The three monthly reports, with their 70 line items, tell us how to run the company, tell our managers how well they know their units, and tell our employees if there’s going to be a profit. Everyone works on the basis of the same information, and everyone looks forward to its appearance with what I’d call fervent curiosity.

And that’s all there is to it. Participation gives people control of their work, profit sharing gives them a reason to do it better, information tells them what’s working and what isn’t.

Letting Them Do Whatever the Hell They Want

So we don’t have systems or staff functions or analysts or anything like that. What we have are people who either sell or make, and there’s nothing in between. Is there a marketing department? Not on your life. Marketing is everybody’s problem. Everybody knows the price of the products. Everybody knows the cost. Everybody has the monthly statement that says exactly what each of them makes, how much bronze is costing us, how much overtime we paid, all of it. And the employees know that 23% of the after-tax profit is theirs.

We are very, very rigorous about the numbers. We want them in on the fourth day of the month so we can get them back out on the fifth. And because we’re so strict with the financial controls, we can be extremely lax about everything else. Employees can paint the walls any color they like. They can come to work whenever they decide. They can wear whatever clothing makes them comfortable. They can do whatever the hell they want. It’s up to them to see the connection between productivity and profit and to act on it.

Ricardo Semler, 30, is president of Semco S/A, Brazil’s largest marine and food-processing machinery manufacturer, and his book, Turning the Tables, has been on Brazil’s best-seller list for 60 weeks. He is vice president of the Federation of Industries of Brazil and a board member of SOS Atlantic Forest, Brazil’s foremost environmental defense organization.

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12 juin 2013 3 12 /06 /juin /2013 07:47

Why My Former Employees Still Work for Me

I own a manufacturing company in Brazil called Semco, about which I can report the following curious fact: no one in the company really knows how many people we employ. When we walk through our manufacturing plants, we rarely even know who works for us. Some of the people in the factory are full-time Semco employees; some work for us part-time; some work for themselves and supply Semco with components or services; some work for themselves under contract to outside companies (even Semco’s competitors); and some of them work for each other. We could decide to find out which is which and who is who, but for two good reasons we never bother. First, the employment and contractual relationships are so complex that describing them all would take too much time and trouble. Second, we think it’s all useless information.

Semco has long been a laboratory for unusual employment and management practices. What we’re now engaged in might be called a radical experiment in unsupervised, in-house, company-supported satellite production of goods and services for sale to Semco itself and to other manufacturers by employees, part-time employees, ex-employees, and people who have never had any connection with Semco whatsoever (but who work on our premises and on our equipment). This is not at all the same thing as outsourcing. This is a borderless system of short-term, noncontractual task assignment often using Semco’s own fixed assets, some of it in Semco plants and some dispersed at a dozen sites that don’t belong to the company.

This satellite program, as we call it, sounds chaotic, can be frustrating, and is in some ways uncontrollable. It requires daily leaps of faith. It has serious implications for corporate culture. It has destroyed any semblance of corporate security. And, for the three years it has been in place, it seems to be working very well. Since 1990, 28% of Brazilian capital goods manufacturers have gone bankrupt. In 1990, 1991, and 1992, Brazilian gross industrial product fell by 14%, 11%, and 9%, respectively. Capital goods output has fallen back to what it was in 1977. But in this same period, Semco’s overall sales and profits have remained intact, and I attribute the difference first and foremost to our satellite production.

Ever since I took over the company 12 years ago, Semco has been unorthodox in a variety of ways. I believe in responsibility but not in pyramidal hierarchy. I think that strategic planning and vision are often barriers to success. I dispute the value of growth. I don’t think a company’s success can be measured in numbers, since numbers ignore what the end user really thinks of the product and what the people who produce it really think of the company. I question the supremacy of talent, too much of which is as bad as too little. I’m not sure I believe that control is either expedient or desirable.

I don’t govern Semco—I own the capital, not the company—but on taking over from my father, I did try to reconstruct the company so that Semco could govern itself on the basis of three values: employee participation, profit sharing, and open information systems. We’ve introduced idiosyncratic features like factory-floor flextime, self-set salaries, a rotating CEO-ship, and, from top to bottom—from the owner to the newest, greenest maintenance person—only three levels of hierarchy.

You might say that what we practice is an extreme form of common sense: “common” because there’s nothing we do that thousands of other people didn’t think of ages ago, “extreme” because we actually do it. Another way of looking at Semco is to say that we treat our employees like responsible adults. We never assume that they will take advantage of us or our rules (or our lack of rules); we always assume they will do their level best to achieve results beneficial to the company, the customer, their colleagues, and themselves. As I put it in an earlier article in HBR, participation gives people control of their work, profit sharing gives them a reason to do it better, information tells them what’s working and what isn’t.

With rare exceptions, this approach has been successful. We’ve had two or three strikes, but they were quickly settled, especially once the strikers saw that we would neither lock them out of the plant nor suspend their benefits during the work stoppage. (They were able to plan ongoing strike tactics while eating lunch in the company cafeteria.) We’ve had a few employees take wholesale advantage of our open stockrooms and trusting atmosphere, but we were lucky enough to find and prosecute them without putting in place a lot of insulting watchdog procedures for the nine out of ten who are honest. We’ve seen a few cases of greed when people set their own salaries too high. We’ve tried a few experiments that we later backed away from. We’ve had to accept occasional democratic decisions that management disliked, but we learned to swallow hard and live with them.

On the whole, as I say, our approach has worked. Loyalty is high, quality is excellent, and sales and profits are surprisingly good for a manufacturing company in one of the world’s most lunatic business environments. But in Brazil no state of the economy is permanent. Few last long enough to be called temporary. Surviving the ups and downs of the Brazilian economy is a little like riding a Brahma bull. It is even more like riding a Brahma bull in an earthquake. Some of the worst jolts come not from the bull but the landscape.

In 1990, the jolt that sent us into our present experiment came from the minister of finance, who, believing Brazil’s inflation was simply the result of too much money being used for too much speculation, seized 80% of the country’s cash and introduced an extended period of economic bedlam. Employers could not meet payrolls. Consumer spending vanished. Business spending shuddered to a halt. Bankruptcies soared. Industrial output plummeted.

At Semco, we had several months of zero sales. After all, what company was going to buy machinery with a ten-month delivery when it didn’t know if it could last out the week? Worse yet, back orders were canceled, or we found that our customers had gone out of business. Our marine division alone had $1.5 million of receivables that we couldn’t hope to collect and $4 million worth of products that shipbuilders could no longer pay for. We had to rent warehouse space just to store all the unsold goods.

We cut costs. We organized workers into teams and sent them out to sell replacement parts directly to ships and restaurants. We cut down on coffee breaks, locked up the copiers, canceled orders for new uniforms, turned off all the lights we could find, scrimped on telephone calls. None of it was enough, and anyway, I don’t really believe in cost-cutting. I like to think we don’t waste money even when we’ve got it. And who can say how many sales we lose when we play Scrooge with the travel money or penny-pinch the phone bills?

Finally, we called the workers together in groups of 100 and discussed what we should do. They came up with lots of ideas, and we tried them without success until we reached a point where no one had anything else to propose and neither did we—except for two unhappy alternatives: cut pay or cut workforce. We thought we could avoid layoffs by cutting salaries 30% across the board until business picked up again. But a lot of people were already struggling with bills and rents and mortgages and wanted us to start laying people off instead, so that those who stayed could at least survive. We went on searching desperately for a third way out.

And then suddenly the shop-floor committee came to us and said, “Okay, we’ll take a 30% pay cut, but on three conditions.” The first was that we increase their profit sharing by 15%, from just under 24% to just under 39%, until they got back up to their former salary levels. The second was that management take a 40% pay cut. And the third was that a member of the union committee would co-sign every check we wrote; because the workers wanted to be absolutely certain that their sacrifice would be worthwhile, they wanted to oversee each and every expenditure.

Well, at that moment, we had no profits to share, so there was nothing for us to lose and everything to gain. And by the second month, we were actually covering expenses. In their drive to save, the workers took on more and more of the former contract work. They did security and cleaning, drove trucks, even cooked the food in the cafeteria. No expense went unchallenged, and for four or five months, we made a small profit in the worst economic times any of us had ever seen.

But we kept on looking for a better solution.

In the first place, pure cost reduction has to be a temporary measure. What about training, research, new product development, and all the other seemingly peripheral activities that produce profits over the long haul? Those weren’t responsibilities we could abdicate.

And what about those checks? The dual-signature scheme was working for the moment, but management couldn’t permanently yield its power of the purse to a person chosen by the union without management input or approval.

Yet the explosion of energy, inventiveness, and flexibility we’d been witnessing was hugely attractive. And when we then added in several other factors—the need to cut our standing labor costs, the demands of Brazilian labor law, the dynamic example of our own peculiar Nucleus of Technological Innovation, which I’ll come back to in a moment—what began taking shape was a radically new principle of organization.

The Thinkodrome at the Free-for-All Corporation

Years ago, in the mid-1980s, three Semco engineers proposed a new kind of work unit. They wanted to take a small group of people raised in Semco’s culture and familiar with its products and set them free. The new group would not have to worry about production problems, sales, inventory, equipment maintenance, delivery schedules, or personnel. Instead, they would invent new products, improve old ones, refine marketing strategies, uncover production inefficiencies, and dream up new lines of business. They would have no boss and no subordinates. They would pick their own focus, set their own agendas, and have complete freedom to change their minds. Twice a year they’d report to senior management, which would decide whether or not to keep them on for another six months.

The three engineers suggested we call the new unit the Nucleus of Technological Innovation (NTI) and somewhat predictably proposed themselves as its first three members. We bought their odd idea, and then we worked out an odd form of compensation to go along with it. Their guaranteed salaries went sharply down, but they would now share in the proceeds of their inventions, innovations, and improvements. They would receive a percentage of any savings they introduced, royalties on new products they devised, a share of the profits on their inventions, and they would also be free to sell consulting services on the open market. They might have done even better as truly independent entrepreneurs, but as NTI members, Semco would cushion them against disaster and give them the support of an established and well-equipped manufacturing operation.

By the end of their first six months, NTI had 18 projects under way, and over the next few years they uncorked such an array of inventions, changes, and refinements (one of my favorites is a scale that weighs freight trains moving at full speed) that NTI’s members began to prosper mightily and Semco became unthinkable without their constant innovation and reform.

By 1990, we’d begun to feel that we’d like to NTI the entire company, liberate more creativity, tie compensation even more specifically to performance, loosen the ties that bound us all together, and scramble our overall structure. The 30% pay-cut-and-cost-reduction scheme had given us a breathing space of several months, but with the Brazilian economy in a bucket and no imminent prospect of recovery, we had to become permanently leaner and more flexible. At the same time, of course, we had a commitment to our workforce that was central to the way we did business. That commitment had been our principal reason for trying to avoid layoffs.

For most other companies, there was another reason as well: Brazilian labor law protects laid-off workers by granting them several different forms of special compensation. The largest of these comes from an individual fund for each worker to which the employer contributes 8% of wages every month. When people are fired (or retire), they collect all this accumulated money, plus interest, in the form of a lump sum. Less substantial—but, unlike the 8% fund, a great problem for many employers—is severance pay itself, which is paid on the spot out of current income and which can amount to two years’ salary in the case of workers with many years’ seniority. By the end of 1990, a lot of Brazilian companies drifted slowly into bankruptcy rather than lay people off and go bankrupt overnight. With our finances still more or less intact, this widespread problem proved in our case to be an opportunity.

Semco’s sales had gradually increased again, and we were making enough money to restore salaries to where they had been before the 30% cut. We took back our check-signing privileges. We were surviving in a crisis economy, but only just, and we began to face the fact that we had to cut our permanent staff and contract more of our work. We looked hard for a way of doing it without destroying the support system that Semco people lived on. It was here that NTI’s free-form structure suggested a solution.

Instead of giving contracts out to strangers, we decided we could just as well give contracts to our own employees. We would encourage them to leave the Semco payroll and start their own satellite enterprises, doing work, at least initially, for Semco. Like NTI, these satellites could stay under our larger umbrella by leasing our machines, even working in our plant. Like NTI, they could also do work for other companies, again on our machines and in our factories. Like NTI, their compensation would take a variety of forms—contract payment, royalties, commissions, profit sharing, piecework, whatever they could think up that we both could live with. And like NTI, they could have some beginning guarantees. In particular, we would offer all of them some contract work to cut their teeth on, and we would defer the lease payments on all equipment and space for two full years.

This satellite program would have obvious advantages for Semco. We could reduce our payroll, cut inventory costs by spreading out raw materials and spare parts among our new suppliers, and yet enjoy the advantage of having subcontractors who knew our business and the idiosyncrasies of our company and our customers. Moreover, we would pick up the benefit of entrepreneurial motivation. Because of profit sharing, our employees already worked evenings and weekends when necessary, without any prompting from management. Being in business for themselves ought to raise that sense of involvement higher still.

But what in heaven’s name were the advantages for our workers, who’d be giving up a secure nest at Semco for the risks of small business? And in the midst of economic bedlam? To begin with, of course, they all had the chance to make many times what they could earn at Semco—if the economy straightened out. Of course that was a big if. And should the recession persist, they might make less. But only assuming they continued to have a job at Semco, which was becoming an even bigger if with every day that passed. The fact was, they had distressingly few choices. And so did we.

We eased the transition in every way we could. We created a team of executives to teach cost control, pricing, maintenance, inventory management. To provide seed money, we gave people layoff payments on top of severance pay and all the other legally required benefits. Many also made use of their 8% nest-egg funds. No one had to start a satellite. Some took their severance and left. Some managed to stay on the payroll for months or for good. But despite the difficulties, satellites sprang up quickly. White-collar workers were the first. Our tax accountants, human resource staffers, and computer programmers all went off on their own. Then blue-collar workers in food service and refrigerations systems followed suit.

Today, about half the manufacturing we once did in-house has gone to satellites, and we think we can farm out another 10% to 20%in the coming years. Best of all, to this day only one satellite has failed. Some are expanding and looking for partners. Some satellite workers have been rehired by the company, and a few have moved repeatedly back and forth between satellite and employee status as needs—theirs and ours—shifted. Some satellites have broadened their scope so greatly that most of their time—often right on our premises, remember—is spent with customers and production partners who have no other connection with Semco whatsoever.

In 1990, Semco had about 500 employees. Today, we have about 200, plus at least that many in our satellites, with another 50 or 60 people who work for a satellite and also work for us part-time. We have employees with fixed salaries. We have employees with variable salaries made up of royalties or bonuses based on self-set objectives like cash flow, sales, profits, production units, or any one of a dozen other measures. We have employees with both fixed and variable salaries. All our employees share in our profits.

On the satellite side, compensation may take the form of a fixed fee, an hourly stipend, a percentage of increased sales, a finder’s fee, an honorarium, a retainer converting to an advance converting to a royalty, or even a simple win-or-lose commission. In one case, we had decided to kill a product-development project when one of our people picked it up from the table and said, “I’ll take it. If you’ll give me $1,000 a month, which will just pay my expenses, plus a 7% royalty for the first five years if I can make it work—I’ll take it.” So of course we gave it to him. The most we can lose is $1,000 a month, where we’d been spending $10,000 to $15,000 a month and getting nowhere. The most he can make is something like half a million, I’d guess, with the other 93% coming to Semco.

Once we posted a job for one engineer and got 1,430 résumés. We took them home in packs of a hundred, and then we interviewed for five months. In the end, we invited several dozen final candidates to a one-day seminar where we walked them through the entire company, opened our files, showed them everything we did, then asked them for proposals. We wound up hiring 41 engineers—one salaried employee and 40 satellite workers whom we paid on various forms of percentage-based commission.

In one of our plants, we’ve set aside a large room full of desks and computers to give everyone within our company sphere and, for all we know, a variety of guests and visitors from well beyond it, a place to sit and plan and ask questions and solve problems. We call it the Thinkodrome, and it’s a busy, quiet place. That Semco survives at all we owe in large part to surrounding ourselves with people who look at everything we do and ask why we can’t do it better or cheaper or faster or in some entirely novel way.

Hunting the Free Market

Our ancestors laid out the ground rules of human teamwork several thousand generations ago, and they go like this: the woman with the keen eyesight is Chief Mammoth Finder, the guy with the strong arm and the long spear is Head Mammoth Killer, and the tribal elder with the special feel for herbs and spices gets to be Grand Mammoth Cook. For now. All these positions are temporary and to some extent self-selecting. If you want to be Chief Finder, go find some mammoths and the job is probably yours. But since everyone’s well-being depends on your success, your status is also highly situational. Fail to find, and the job will pass swiftly and naturally to someone else.

Generally speaking, Semco’s production process works along similar lines, both for satellite operations and for the work we do in-house. All work, including some aspects of management, goes to people with proven track records who want the jobs and can compete for them successfully. Satellite as well as in-house business units rise and fall on their merits alone—at least in theory.

This commitment to free-market principles was put to the test about a year into the satellite program, when our marine division found itself with a good deal of idle capacity. Marine’s strategy was built on quality, not price—low volume but high margins. A shipbuilder seeking the very best performance and dependability in, say, a propeller system, tended to come to us. But with the economy in a straitjacket, orders had nearly disappeared.

On the other hand, our biscuit division, which designs and builds turnkey cookie factories for global giants like Nabisco and Nestlé, had two fairly big contracts in hand, one for about $2 million, another for $5.5 million, and was going to need a lot of skilled subcontracting. The portion of this work that marine could do would keep it occupied for four or five months, and marine’s top manager (called a counselor at Semco) went ahead and figured the contracts from the biscuit division into his budget. But biscuit’s purchasing people did not award the contracts to the marine division, which took too long to deliver, they said, and which charged too high a price for its exaggerated quality. They gave the contracts instead to satellite producers and outside contractors, including one of marine’s archcompetitors. The fight that triggered was a bitter one, and the attempts of the interdepartmental management meeting to act as go-between did not make things easier. We were of two minds ourselves.

On the one hand, we were going to pay marine employees to sit around on their hands while another division paid outsiders to do work the marine employees could have done. And on the other hand, how could we ask biscuit employees, who share in their division’s profits, to subsidize a business in trouble? Moreover, wouldn’t the subsidy just postpone marine’s inevitable reckoning with its own strategic predicament? In the end, we let biscuit have its way and endorsed the need to be as unforgiving toward our own business units as we would be toward outsiders. It was the right decision, of course. We finished the cookie factories on schedule, and the marine division—which decided to stick with its high-quality, high-margin strategy but to eliminate a number of products whose quality and cost were too high for the market—cut its staff by 70%, began farming out a lot of its work to satellites, and recovered its profitability.

Control...

At the center of Semco is a group of six so-called counselors, and all of us take six-month turns as acting CEO. We also do six-month as opposed to yearly budgeting, because an annual budget tempts managers to postpone unpleasant decisions to the third and fourth quarters.

The budget cycles are January to June and July to December, but the CEO cycles begin in March and September. In other words, we avoid what other companies and shareholders think they want—responsibility nailed down to a single man or woman. Our CEOs don’t wear themselves out trying to meet quarterly financial goals, and there’s no one person to blame if the company goes down the drain. When financial performance is one person’s problem, then everyone else can relax. In our system, no one can relax. You get to pass on the baton, but it comes back again two-and-a-half years later.

One consequence of this system is that we need to keep each other well-informed, which we do at regular weekly divisional meetings and biweekly interdivisional meetings. All these meetings are open and optional, and those who attend make decisions that those who don’t may simply have to live with.

This self-selecting element in decision making is another consequence of the deliberate fragmentation of responsibility. Like our predecessors the mammoth hunters, the people who get responsibility are the people who seek it out and meet it. In fact, the actual, ad hoc control structure we work with from day to day builds on this principle and on two others that, together, create a kind of invisible order from the apparent chaos that characterizes the Semco environment.

The first principle holds that information is the ultimate source of virtually all power. For this reason, we try to make all of it available to everyone. All meetings are open. Designs and specifications are shared. The company’s books are open for inspection by employees and for auditing by their unions. In short, we try to undercut and so eliminate the process of filtering and negotiating information that goes on in so many corporations. Meetings are chaired by the person who knows most about the subject under discussion rather than by the person who has the highest declared status or apparent income.

The second principle is that the responsibility for any task belongs to the person who claims it.

The third is that profit sharing for employees and success-oriented compensation for satellite enterprises will spread responsibility across the Semco map. With income and security at risk—and with information readily available—people try hard to stay aware of everyone else’s performance.

To give an idea of how all this works in practice, let’s take one of those turnkey cookie factories. The Big Cracker Company of Chicago wants a plant that will turn out a thousand tons a month of, say, butterscotch macaroons. To begin with, an independent agent will tell us of the project in return for a finder’s fee. We will probably put the initial customer interface in the hands of a satellite company—four men who used to be on our payroll and now work for themselves. They’ll go through the specifications with the customer, then they’ll share that information widely, announce a meeting (to which anyone can come and no one is summoned), and chair the discussion (which will cover several unexpected proposals from unanticipated participants like the guy from refrigeration with a special point of view about handling butter and coconut). Someone, a group of employees or satellites, will take on the job of costing the project, and with this cost estimate in hand, a Semco counselor and biscuit-division coordinators will then set a margin and deliver the quote to Big Cracker.

(A couple of times, we have even communicated this margin to the customer, because we thought it would be easier to justify, for example, a 12% net margin than to play the disingenuous game of claiming pencil-thin profits and no room for compromise. Our chief argument has been our profit-sharing program, since it seems so clear to us that people will work harder for more money and that a generous margin will therefore buy the customer much extra care and effort. But I’m afraid we’ve had only limited success with this approach.)

This margin-setting discussion often produces serious disagreements. In one case, we battled out the margin in a long, heated debate, and then the sales manager lowered it dramatically when he sat down with the customer. By Semco rules, that kind of last-minute capitulation is perfectly legitimate. Battle or no battle, he was with the customer, not we. Whoever holds the spear is completely in charge of bringing down the mammoth.

Let’s say Big Cracker accepts our bid and the order comes in, 600 pages long. Let’s also say we choose a coordinator for the project from outside the company, and let’s call him Bob. Bob will go through the contract and decide how he wants to divide it up. He may get help from engineering. He will certainly get help from all the meetings he holds to make decisions, which he will chair and where he will lobby for the people he wants to do each job. Next, the biscuit division’s purchasing department will negotiate contracts with the dozens of suppliers chosen. In 1991, we did about 70% of such a contract in-house. Today, that’s down to 35% or 40%.

When Bob has put together a completion schedule and time chart, everyone will go to work—each contractor, employee, and satellite responsible to no single authority but answerable to everyone. At most companies, when something goes wrong the real responsibility falls between the cracks. At Semco, the fact that Bob is not an employee makes everyone react much faster when there looks like trouble.

...And Lack of Control

Semco needs to maintain in-house just a limited number of functions—top management, applications engineering, some R&D, and some high-tech, capital-intensive skills that we do exceptionally well. We don’t care how everything else gets done, whether by contractors or subcontractors, satellites or nonsatellites, former employees or total strangers or by the very people who do the same thing for our competition. None of that matters.

When we started, people warned me that all sorts of information about our company would get into the wrong hands, that we had to protect ourselves. I heard the same argument when we started distributing profit-and-loss statements to our employees. But it’s a waste of time to worry about leaks.

First of all, we no longer know whose the wrong hands are. The competition used to be a company a mile away that made the same products we did, but now the competition comes from companies we’ve never heard of in Taiwan and Finland. Second, I’ve never seen a company overtake another because it had seen its 10K or even the specifications for a valve. Third, we want to be a moving target. We don’t care about yesterday’s information or last year’s oil pump, which in any case the competition can buy, take apart, and study to its heart’s content.

Finally, we don’t think people give out much information anyway. I know. I’ve tried on numerous occasions to get a copy of, let’s say, a pamphlet some company passed out to 1,000 employees, and nobody can lay their hands on one. The Chinese printed hundreds of millions of copies of Chairman Mao’s Little Red Book, and still they’re as rare as hen’s teeth.

People also warned me about the loss of central goal setting and control. I admit that the lack of control is often hard to live with. But let’s not compare Semco’s circumstances with some ideal world where managers actually get to decide what people will do and when and how they’ll do it. We have limited control over the day-to-day behavior of the people who make most of our components, but so do companies that do all their work in-house. At least none of our satellite people work nine to five and leave their problems at the plant when they go home at night—which means leaving them to management. We have motivation and responsibility working on our side. Our satellite workers are in business for themselves, so they’ll work all night to complete an order to specification and on time. And if the order is late or fails to meet our quality standards, then we’re free to give the next order to someone else. We can forget the witch-hunt and all the grief that goes into firing people or not promoting them.

As for planning and the control it presupposes, I think good planning is always situational. Thinking about the future is a useful, necessary exercise, but translating such conjecture into “Strategic Planning” is worse than useless. It’s an actual barrier to survival. Strategic planning leads us to make things happen that fly full in the face of reality and opportunity.

For example, Semco is today in the environmental consulting business, which I could not have imagined five years ago. Our gadfly NTI group was looking at one customer’s need for an environmentally active pump—a pump that would shred and process the material it moved—and saw that the company could reengineer its production line to do away with the pump altogether. Had we said, “We’re in the pump business, not the environmental business,” we might never have pursued that solution to the problem. As it was, we addressed the company’s overall need, jettisoned the pump, and when it was all over, we’d also acquired a small environmental consulting firm to flesh out our own limited expertise. More recently, we’ve also entered into a joint venture with one of the world’s leading environmental consulting groups. Today, the division represents about 14% to 15% of our total business and is growing at a rate of 30% to 40% per year.

The lesson this story teaches me is about the negative value of structure. Structure creates hierarchy, and hierarchy creates constraint. We have not utterly abandoned all control, but the old pyramidal hierarchy is simply unable to make leaps of insight, technology, and innovation. Within their own industries, pyramidal hierarchies can generate only incremental change.

Take dishwashers, one of Semco’s businesses. Dishwashers are expensive to operate and messy to use, but over the last 50 years, dishwashers have changed hardly at all. What the customer wants is a machine that washes dishes silently, cheaply, and without any mess at all, which probably means without water. I’ve recently seen indications that such a thing may be possible, but the idea could never have come from a pyramid of Semco dishwashing executives. It was one of our satellites that brought us the idea. In fact, about two-thirds of our new products come from satellite companies.

What goes for planning goes equally for culture, vision, and responsibility. We find that fragmentation is strength in all these areas. Semco has no corporate credo, for example, and no mission statement. An articulation of company values or vision is just a photograph of the company as it is, or wants to be, at one given moment. Snapshots of this kind seem to hold some companies together, but they are terribly static devices. No one can impose corporate consciousness from above. It moves and shifts with every day and every worker. Like planning, vision at its best is dynamic and dispersed.

At Semco, so is responsibility. We have little control, even less organization, and no conventional discipline at all. People come and go whenever they like; many set their own compensation; divisions and units perpetuate themselves however they can; satellite companies work on our machines in our factories for us and others in a great confusion of activity; the system tying it all together is painfully loose—and this is manufacturing, much of it assembly-line manufacturing.

When I describe Semco to other manufacturers, they laugh. “What do you make,” they ask me, “beads?” And I say, “No, among other things, we make rocket-fuel propellant mixers for satellites.” And they say, “That’s not possible.” And I say, “Nevertheless...”

The point is simple but perhaps not obvious. Semco has abandoned a great many traditional business practices. Instead, we use minimal hierarchies, ad hoc structures, self-control, and the discipline of our own community marketplace of jobs and responsibilities to achieve high-quality, on-time performance. Does it make me feel that I have given up power and governance? You bet it does. But do I have more sleepless nights than the manufacturer who runs his business with an iron hand and whose employees leave their troubles in his lap every night? I think I probably sleep better. I know I sleep well.

We delivered our last cookie factory with all its 16,000 components right on time. One of our competitors, a company with tight controls and hierarchies, delivered a similar factory to the same client a year and two months late.

In 1990 and again in 1992, Ricardo Semler—majority owner of a São Paulo manufacturing company, Semco S/A, that specializes in marine and food-service equipment—was elected business leader of the year by a poll of 52,000 Brazilian executives. His book, Maverick, published recently by Warner Books in the United States and simultaneously in 14 other languages, has sold some 800,000 copies worldwide, half of these in Brazil, where it was on the best-seller list for 200 weeks. His HBR article “Managing Without Managers” appeared in September–October 1989.

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12 juin 2013 3 12 /06 /juin /2013 07:36

How We Went Digital Without a Strategy

I own a $160 million South American company named Semco, and I have no idea what business it’s in. I know what Semco does—we make things, we provide services, we host Internet communities—but I don’t know what Semco is. Nor do I want to know. For the 20 years I’ve been with the company, I’ve steadfastly resisted any attempt to define its business. The reason is simple: once you say what business you’re in, you put your employees into a mental straitjacket. You place boundaries around their thinking and, worst of all, you hand them a ready-made excuse for ignoring new opportunities: “We’re not in that business.” So rather than dictate Semco’s identity from on high, I’ve let our employees shape it through their individual efforts, interests, and initiatives.

That rather unusual management philosophy has drawn a good deal of attention over the years. Nearly 2,000 executives from around the world have trekked to São Paulo to study our operations. Few, though, have tried to emulate us. The way we work—letting our employees choose what they do, where and when they do it, and even how they get paid—has seemed a little too radical for mainstream companies.

But recently a funny thing happened: the explosion in computing power and the rise of the Internet reshaped the business landscape, and the mainstream shifted. Today, companies are desperately looking for ways to increase their creativity and flexibility, spur their idea flow, and free their talent—to do, in other words, what Semco has been doing for 20 years.

I don’t propose that Semco represents the model for the way businesses will operate in the future. Let’s face it: we’re a quirky company. But I do suggest that some of the principles that underlie the way we work will become increasingly common and even necessary in the new economy. In particular, I believe we have an organization that is able to transform itself continuously and organically—without formulating complicated mission statements and strategies, announcing a bunch of top-down directives, or bringing in an army of change-management consultants. As other companies seek to build adaptability into their organizations, they may be able to learn a thing or two from Semco’s example.

Transformation Without End

Over the last ten years, Semco has grown steadily, quadrupling its revenues and expanding from 450 to 1,300 employees. More important, we’ve extended our range dramatically. At the start of the ’90s, Semco was a manufacturer, pure and simple. We made things like pumps, industrial mixers, and dishwashers. But over the course of the decade, we diversified successfully into higher-margin services. Last year, almost 75% of our business was in services. Now we’re stretching out again—this time into e-business. We expect that more than a quarter of our revenues next year will come from Internet initiatives, up from nothing just one year ago. We never planned to go digital, but we’re going digital nonetheless.

You may wonder how that’s possible. How do you get a sizable organization to change without telling it—or even asking it—to change? It’s actually easy—but only if you’re willing to give up control. People, I’ve found, will act in their best interests, and by extension in their organizations’ best interests, if they’re given complete freedom. It’s only when you rein them in, when you tell them what to do and how to think, that they become inflexible, bureaucratic, and stagnant. Forcing change is the surest way to frustrate change.

Enough lecturing. Let me give you a concrete example of how our transformation has played out. Ten years ago, one of the things we did was manufacture cooling towers for large commercial buildings. In talking with the property owners who bought these products, some of our salespeople began to hear a common refrain. The customers kept complaining about the high cost of maintaining the towers. So our salespeople came back to Semco and proposed starting a little business in managing cooling-tower maintenance. They said, “We’ll charge our customers 20% of whatever savings we generate for them, and we’ll give Semco 80% of those revenues and take the remaining 20% as our commission.” We said, “Fine, give it a shot.”

Well, the little business was successful. We reduced customers’ costs and eliminated some of their hassles, and they were happy. In fact, they were so happy that they came back and asked if we’d look after their air-conditioning compressors as well. Even though we didn’t manufacture the compressors, our people didn’t hesitate. They said yes. And when the customers saw we were pretty good at maintaining compressors, they said, “You know, there are a lot of other annoying functions that we’d just as soon offload, like cleaning, security, and general maintenance. Can you do any of those?”

At that point, our people saw that their little business might grow into quite a big business. They began looking for a partner who could help bolster and extend our capabilities. They ended up calling the Rockefeller Group’s Cushman & Wakefield division, one of the largest real-estate and property-management companies in the United States, and proposing that we launch a 50–50 joint venture in Brazil. Cushman wasn’t very keen on the idea at first. People there said, “Property management by itself isn’t a very lucrative business. Why don’t we talk about doing something that involves real estate? That’s where the money is.”

We spent some time thinking about going into the real-estate business. We didn’t have any particular expertise there, but we were willing to give it a try. When we started asking around, though, we found that no one in the company had much interest in real estate. It just didn’t get anyone excited. So we went back to the Cushman folks and said, “Real estate sounds like a great business, but it’s not something we care about right now. Why don’t we just start with property management and see what happens?” They agreed, though not with a lot of enthusiasm.

We ponied up an initial investment of $2,000 each, just enough to pay the lawyers to set up a charter. Then we set our people loose. In no time, we had our first contract, with a bank, and then more and more business came through the door. Today, about five years later, the joint venture is a $30 million business.

It’s also the most profitable property-management business within Cushman &Wakefield. The reason it has been so successful is that our people came into it fresh, with no preconceived strategies, and they were willing to experiment wildly. Instead of charging customers in the traditional way—a flat fee based on a building’s square footage—they tried a partnership model. We’d take on all of a property owner’s noncore functions, run them like businesses, and split the resulting savings.

One customer, for example, had been using 126 subcontractors for all sorts of maintenance and security tasks. It was a nightmare to manage, it resulted in poor or haphazard service, and it was ridiculously inefficient. We took over all 126 tasks, from changing lightbulbs to managing the car fleet to maintaining elevators, and we treated each as a separate business. We tore every task apart to see how it could be done better, and we made a series of improvement proposals to the client, ranging from relatively simple operating changes (reducing security personnel by installing video cameras) to highly technical systems installations (revamping the ATM architecture to dramatically reduce downtime). We outlined the investment and the expected gain and shared the cost reduction. The client reaped big savings and service improvements and got a single point of contact for doing everything necessary to run the building. And Semco made a heck of a lot more money than it would have by charging a flat fee.

Most manufacturers would probably consider a shift from making cooling towers to managing buildings pretty radical. Before making such a leap, they’d do a lot of soul-searching about their core businesses and capabilities. They’d run a lot of numbers, hold a lot of meetings, do a lot of planning. We didn’t bother with any of that. We just let our people follow their instincts and apply their common sense, and it worked out fine.

Going to the Net

Our recent move into the digital space has proceeded in much the same way, with our people again taking the lead. In fact, some of the eight Internet ventures we’ve launched grew directly out of our earlier service initiatives. As our facility-management business expanded, for example, we extended it, through a joint venture with Johnson Controls, to managing retail facilities. As our people began to work closely with store managers, they began to notice the huge costs retailers incur from lost inventory. One employee came forward and asked for a paid leave to study opportunities in that area. We gave him a green light, and within a year he had helped us set up a joint venture with RGIS, the largest inventory-tracking company in the world. Less than two years later, the venture had become the biggest inventory-management business in South America. Now it is branching out into Web-enabled inventory control, helping on-line companies coordinate the fulfillment of electronic orders.

Our work in property management also brought us face to face with the disorganization and inefficiency of the construction business. Here, too, our people saw a big business opportunity, one that would build on the unique capabilities of the Internet. A number of the members of our joint ventures with Cushman & Wakefield and Johnson Controls banded together, with Semco’s support, to set up an on-line exchange to facilitate the management of commercial construction projects. All the participants in a building project—architects, banks, construction companies, contractors, and project managers—can now use our exchange to send messages, hold real-time chats, issue proposals and send bids, and share documents and drawings. They can collaborate even if they’re using different software, because the Web platform automatically does all the translation. The exchange is revolutionizing the construction process here in Brazil.

That business, which we’re operating as a 50–50 joint venture with the U.S. Internet software company Bidcom, has itself become a springboard for further new initiatives. One of the most exciting is the creation of a South American Web portal for the entire building industry. The portal, called Edify, provides a single point of access for all the people, goods, and services required for a construction project. It’s a place where contractors can hire tradesmen, hardware stores can sell lumber and fixtures, homeowners can buy insurance and cable television service, and real-estate agents and interior decorators can promote their offerings. We make money by charging transaction fees on all the business that takes place through the portal.

We’re also partnering with a company called eTradeshow to host virtual construction fairs within the portal. As our people began to work closely with construction companies, they realized that many sectors of the South American building trade—flooring and masonry, for example—aren’t large enough to pay the costs of physical trade shows. As a result, new ideas and products have been slow to enter the markets. We saw that on-line shows would be highly attractive to these sectors, providing them access not only to new products but to potential new partners all around the world. We’ll be holding 60 different fairs on the site. In addition, we’ll be hosting virtual versions of major international trade shows in such industries as automobiles, computers, and medical equipment. Visitors will be able to walk through a 3-D representation of the trade-fair space, collect business cards and brochures, watch presentations, and chat with sales representatives. These shows will generate fees for us while driving more traffic to the portal.

Management Without Control

Semco’s ongoing transformation is a product of a very simple business philosophy: give people the freedom to do what they want, and over the long haul their successes will far outnumber their failures. Operationalizing that philosophy has involved a lot of trial and error, of taking a few steps forward and a couple back. The company remains a work in progress—and I hope it stays that way forever.

As I reflect on our experience, though, I see that we’ve learned some important lessons about creating an adaptive, creative organization. I’ll share six of those lessons with you. I won’t be so presumptuous as to say they’ll apply to your company, but at least they’ll stir up your thinking.

Forget about the top line.

The biggest myth in the corporate world is that every business needs to keep growing to be successful. That’s baloney. The ultimate measure of a business’s success, I believe, is not how big it gets, but how long it survives. Yes, some businesses are meant to be huge, but others are meant to be medium-sized and still others are meant to be small. At Semco, we never set revenue targets for our businesses. We let each one find its natural size—the size at which it can maintain profitability and keep customers happy. It’s fine if a business’s top line stays the same or even shrinks as long its bottom line stays healthy. Rather than force our people to expand an existing business beyond its natural limits, we encourage them to start new businesses, to branch out instead of building up.

Never stop being a start-up.

Every six months, we shut down Semco and start it up all over again. Through a rigorous budgeting and planning process, we force every one of our businesses to justify its continued existence. If this business didn’t exist today, we ask, would we launch it? If we closed it down, would we alienate important customers? If the answers are no, then we move our money, resources, and talent elsewhere. We also take a fresh look at our entire organization, requiring that every employee—leaders included—resign (in theory) and ask to be rehired. All managers are evaluated anonymously by all workers who report to them, and the ratings are posted publicly. It has always struck me as odd that companies force new business ideas and new hires to go through rigorous evaluations but never do the same for existing businesses or employees.

Don’t be a nanny.

Most companies suffer from what I call boarding-school syndrome. They treat their employees like children. They tell them where they have to be at what time, what they need to be doing, how they need to dress, whom they should talk to, and so on. But if you treat people like immature wards of the state, that’s exactly how they’ll behave. They’ll never think for themselves or try new things or take chances. They’ll just do what they’re told, and they probably won’t do it with much spirit.

At Semco, we have no set work hours, no assigned offices or desks, no dress codes. We have no employee manuals, no human resource rules and regulations. We don’t even have an HR department. People go to work when they want and go home when they want. They decide when to take holidays and how much vacation they need. They even choose how they’ll be compensated. (See the sidebar “Eleven Ways to Pay.”) In other words, we treat our employees like adults. And we expect them to behave like adults. If they screw up, they take the blame. And since they have to be rehired every six months, they know their jobs are always at risk. Ultimately, all we care about is performance. An employee who spends two days a week at the beach but still produces real value for customers and coworkers is a better employee than one who works ten-hour days but creates little value.

Let talent find its place.

Companies tend to hire people for specific jobs and then keep them stuck in one career track. They also tend to choose which businesses people work in. The most talented people, for instance, may be assigned automatically to the business unit with the biggest growth prospects. The companies don’t take into account what the individual really wants. The resulting disconnect between corporate needs and individual desires shows up in the high rates of talent churn that afflict most companies today.

We take a very different approach. We let people choose where they’ll work and what they’ll do (and even decide, as a team, who their leaders will be). All entry-level new hires participate in a program called Lost in Space. They spend six months to a year floating around the company, checking out businesses, meeting people, and trying out jobs. When a new hire finds a place that fits with his personality and goals, he stays there. Since our turnover rate in the past six years has been less than 1%—even though we’ve been targeted heavily by headhunters—we must be doing something right.

Make decisions quickly and openly.

The best way for an organization to kill individual initiative is to force people to go through a complicated, bureaucratic review and approval process. We strive to make it as easy as possible for Semco employees to propose new business ideas, and we make sure they get fast and clear decisions. All proposals go through an executive board that includes representatives from our major business units. The board meetings are completely open. All employees are welcome to attend—in fact, we always reserve two seats on the board for the first two employees who arrive at a meeting. Proposals have to meet two simple criteria that govern all the businesses we launch. First, the business has to be a premium provider of its product or service. Second, the product or service has to be complex, requiring engineering skills and presenting high entry barriers. Well-considered proposals that meet those standards get launched within Semco. Even if a proposed business fails to meet both criteria, we’ll often back it as a minority investor if its prospects look good.

Partner promiscuously.

To explore and launch new businesses quickly and efficiently, you need help; it’s pure arrogance to assume you can do everything on your own. I’m proud to say that we partner promiscuously at Semco. Indeed, I can’t think of a single new business we’ve started without entering into some kind of alliance, whether to gain access to software, draw on a depth of experience, bring in new capabilities, or just share risk. Partnerships have provided the foundation for our experiments and our expansion over the years. Our partners are as much a part of our company as our employees.

Staying Free

I travel a lot in my job, and recently I’ve been spending time in Silicon Valley. I’ve been visiting Internet companies, talking with technology visionaries, and participating in panel discussions on the future of business. The new companies and their founders excite me. I see in them the same spirit we’ve nurtured at Semco—a respect for individuals and their ideas, a distrust of bureaucracy and hierarchy, a love for openness and experimentation.

But I’m beginning to see troubling signs that the traditional ways of doing business are reasserting their hegemony. Investors, I fear, are starting to force young start-ups into the molds of the past—molds that some thought had been broken forever. CEOs from old-line companies are being brought in to establish “discipline” and “focus.” Entrepreneurs are settling into corner offices with secretaries and receptionists. HR departments are being formed to issue policies and to plot careers. Strategies are being written. The truly creative types are being caged up in service units and kept further and further from the decision makers.

It’s sad and, I suppose, predictable. But it isn’t necessary. If my 20 years at Semco have taught me anything, it’s that successful businesses do not have to fit into one tight little mold. You can build a great company without fixed plans. You can have an efficient organization without rules and controls. You can be unbuttoned and creative without sacrificing profit. You can lead without wielding power. All it takes is faith in people.

Ricardo Semler is the majority owner of Semco in São Paulo, Brazil. He is the author of two previous HBR articles, “Managing Without Managers” (September–October 1989) and “Why My Former Employees Still Work for Me” (January–February 1994), and the book Maverick (Warner Books, 1993).

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8 juin 2013 6 08 /06 /juin /2013 07:53

How Safe Is Recreational Marijuana?

As more states make recreational marijuana legal, researchers fret about short- and long-term health effects

Marijuana is more popular and accessible in the U.S. than any other street drug. In national surveys, 48 percent of Americans say they have tried it, and 6.5 percent of high school seniors admit to daily use. So it was not too surprising when two states, Washington and Colorado, became the first to legalize recreational marijuana in the November 2012 general election, albeit in limited quantity, for anyone over the age of 21. Activists expect that similar measures will soon win approval in other parts of the country.

Some success with medical marijuana helped to pave the road to wider legalization of pot. Eighteen states and the District of Columbia permit possession and consumption of the drug for medical purposes. Doctors in those jurisdictions may prescribe cannabis to treat or manage ailments ranging from glaucoma—an eye disease in which the optic nerve is damaged—to menstrual cramps. Cancer patients sometimes smoke pot to relieve the pain and nausea brought on by chemotherapy, and some people with the inflammatory disease multiple sclerosis rely on marijuana to ease muscle stiffness.

Although many physicians agree that marijuana is safe enough to temporarily alleviate the symptoms of certain medical conditions, the safety of recreational use is poorly understood. Researchers worry that both the short- and long-term use of the drug may harm the body and mind. Marijuana's continued popularity among teenagers raises particular concern because the drug might hinder the ongoing maturation of the adolescent brain. Making matters worse, new growing techniques for the Cannabis sativa plant—from which marijuana is prepared—have dramatically increased the drug's potency. Some experts suggest that such high-octane weed is fueling a rise in cannabis addiction. Finally, although investigators still debate how the legalization of recreational marijuana will change road safety overall, studies indicate that the drug slows reaction time and impairs distance perception behind the wheel. Despite such evidence, most new marijuana regulations, for medical or recreational use, fail to account for these potential risks.

Weeded Out

Whether rolled into a joint or mixed into brownie batter, marijuana profoundly changes behavior and awareness. The primary psychoactive compound in marijuana, tetrahydrocannabinol (THC), mimics the structure of molecules called endocannabinoids that the human body produces naturally. Endocannabinoids act on a group of cell-surface molecules called cannabinoid receptors that help to regulate appetite, mood and memory. Because of its shape, THC fits into these receptors, too. After all, jokes neuroscientist Giovanni Marsicano of the University of Bordeaux in France, “We don't have a receptor in the body just to smoke marijuana.”

When THC strikes specific cannabinoid receptors, it triggers domino chains of interacting molecules in neurons that culminate in both unusually elevated and abnormally low levels of various neurotransmitters (the molecules that brain cells use to communicate with one another). The result is the well-known “high” of marijuana. Suddenly, the mundane seems hilarious, and ordinary foods taste delicious. People generally feel merry, relaxed and introspective, although undesirable effects—such as paranoia and irritability—are common as well.

Marijuana also temporarily impairs an array of mental abilities, especially memory and attention. Dozens of studies have shown, for example, that people under the influence of marijuana perform worse on tests of working memory, which is the ability to temporarily hold and manipulate information in one's mind. Participants in these studies have greater difficulty remembering and reciting short lists of numerals and random words. Research has further revealed that cannabis blunts concentration, weakens motor coordination and interferes with the ability to quickly scan one's surroundings for obstacles.

Such mild cognitive deficits may not endanger anyone if a marijuana user lazes on the couch, but it is a different story when someone takes that high on the road. In driving-simulation and closed-course studies, people on marijuana are slower to hit the brakes and worse at safely changing lanes. Investigators still debate, however, at what point these impairments translate to more traffic accidents. A 2009 study found an increased risk of accidents for levels of THC higher than five nanograms per milliliter of blood, which some evidence indicates is as impairing as a blood alcohol concentration around the legal limit of 0.08 percent. Typically one would have to take several puffs of a joint to reach such a concentration. Consequently, voters in Washington State have adopted 5 ng/mL as the upper threshold for drivers.

Enforcing that limit presents a technical challenge, however. Unlike alcohol, marijuana cannot be detected with a relatively unobtrusive Breathalyzer test. Police officers would have to look for it in blood—something that often requires a warrant. “There is currently no practical method for law-enforcement officers at the scene to collect blood samples from suspected DUI cannabis drivers in a timely manner,” says Paul Armentano, deputy director of the Washington, D.C.–based National Organization for the Reform of Marijuana Laws, which advocates the legalization of marijuana. Instead of using a blood test, Armentano says that police should look for poor maneuvering and the smell of pot wafting from the vehicle.

Smoke Signals

Although marijuana's immediate effects are relatively easy to monitor in the lab, the drug's long-term effects on body and mind are harder to determine. So far the results—which admittedly are subject to multiple interpretations—indicate the need for caution. In one recent study, clinical psychologist Madeline Meier of Duke University and her colleagues examined data from 1,037 New Zealanders. They found that people who began using pot earlier in life and used it most frequently over the years experienced an average decline of eight IQ points by the time they turned 38. By comparison, those who never smoked pot had an average increase of one IQ point by the same age.

A reanalysis of the New Zealand data by Ole Røgeberg of the Ragnar Frisch Center for Economic Research in Oslo, however, suggested that the IQ difference could be explained by socioeconomic factors. People who start smoking marijuana at an earlier age are often less intelligent to begin with. Even if this is true, Meier says, her study shows that the IQ drop is greatest for those who started smoking pot as teenagers rather than in adulthood, indicating a worrisome cumulative effect regardless of intelligence. This finding, she thinks, makes it all the more important to discourage the early use of marijuana among teens.

Increasingly potent marijuana of recent years may be driving a sharp rise in cannabis addiction among adolescents, according to a report released last year by the American Society of Addiction Medicine. Between 1993 and 2008, the average concentration of THC in confiscated marijuana jumped from 3.4 to 8.8 percent. Meanwhile hospital and rehabilitation center admission rates for minors abusing marijuana soared by 188 percent between 1992 and 2006. In contrast, admissions for alcohol abuse for the same group over the same period declined by 64 percent.

In addition to tracking levels of THC itself, some researchers have focused on the dangers of lingering contaminants in marijuana sold on the street. Dealers typically sell cannabis by weight, so some use sand or glass beads to make their products heavier. Breathing in these particles over the years may inflame and eventually scar the lungs. An analysis published last year of data on more than 5,000 Americans did not find a decline in lung function among individuals who smoked joints two or three times a month over two decades. The authors emphasize, however, that they did not assess the effect of daily use on lung health. “Somebody should do that study if marijuana is going to become legalized and prescribed” more widely, says Mark Pletcher, an epidemiologist at the University of California, San Francisco, who co-wrote the paper.

Some opponents of legalization worry that lax regulation of medical marijuana foretells even looser laws concerning recreational marijuana. In states that have legalized medical pot, current laws do not guarantee the safety or quality of cannabis products or standardize levels of THC. In Oakland, Calif., people can fill a marijuana prescription at Harborside Health Center, a massive dispensary with a strict quality-control system. Elsewhere in the state, however, people get their medical marijuana at mom-and-pop outfits or on the street. The next big round of ballot initiatives to legalize cannabis in states other than Washington and Colorado could happen as soon as three years from now, in the 2016 presidential election. Until then, researchers have plenty of marijuana health risks to weed through.

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