Amidst the many brain events evoked by a visual stimulus, which are specifically associated with conscious perception, and which merely reflect non-conscious processing? Several recent neuroimaging studies have contrasted conscious and non-conscious visual processing, but their results appear inconsistent. Some support a correlation of conscious perception with early occipital events, others with late parieto-frontal activity. Here we attempt to make sense of those dissenting results. On the basis of a minimal neuro-computational model, the global neuronal workspace hypothesis, we propose a (...) taxonomy which distinguishes between vigilance and access to conscious report, as well as between subliminal, preconscious and conscious processing. We suggest that these distinctions map onto different neural mechanisms, and that conscious perception is systematically associated with a sudden surge of parieto-frontal activity causing top-down amplification. (shrink)

Here Jean-Pierre Changeux elucidates our current knowledge of the human brain, taking an interdisciplinary approach and explaining in layman's terms the complex theories and scientific breakthroughs that have significantly improved our ...

In a remarkable exchange between neuroscientist Jean-Pierre Changeux and philosopher Paul Ricoeur, this book explores the vexed territory between these...

A simple definition of consciousness is sensory awareness of the body, the self, and the world. The fetus may be aware of the body, for example by perceiving pain. It reacts to touch, smell, and sound, and shows facial expressions responding to exter- nal stimuli. However, these reactions are probably preprogrammed and have a subcortical nonconscious origin. Furthermore, the fetus is almost continuously asleep and unconscious partially due to endog- enous sedation. Conversely, the newborn infant can be awake, exhibit sensory (...) awareness, and process memorized mental representations. It is also able to differentiate between self and nonself touch, express emotions, and show signs of shared feelings. Yet, it is unreflective, present oriented, and makes little reference to concept of him/herself. Newborn infants display features characteristic of what may be referred to as basic consciousness and they still have to undergo considerable maturation to reach the level of adult consciousness. The preterm infant, ex utero, may open its eyes and establish minimal eye contact with its mother. It also shows avoidance reactions to harmful stimuli. However, the thalamocortical connections are not yet fully established, which is why it can only reach a minimal level of consciousness. (shrink)

1 INSERM-CEA Unit 562, Cognitive Neuroimaging, Service Hospitalier Fre´de´ric Joliot, Orsay, France, 2 CNRS URA2182 Re´cepteurs and Cognition, Institut Pasteur, Paris, France.

This paper investigates the compatibility between the theoretical framework of the global neuronal workspace theory (GNWT) of conscious processing and the perturbational complexity index (PCI). Even if it has been introduced within the framework of a concurrent theory (i.e. Integrated Information Theory), PCI appears, in principle, compatible with the main tenet of GNWT, which is a conscious process that depends on a long-range connection between different cortical regions, more specifically on the amplification, global propagation, and integration of brain signals. Notwithstanding (...) this basic compatibility, a number of limited compatibilities and apparent differences emerge. This paper starts from the description of brain complexity, a notion that is crucial for PCI, to then summary of the main features of PCI and the main tenets of GNWT. Against this background, the text explores the compatibility between PCI and GNWT. It concludes that GNWT and PCI are fundamentally compatible, even though there are some partial disagreements and some points to further examine. (shrink)

"This wonderfully eloquent and playful colloquy of two brilliant minds gives new life to the old notion of Dialogue, a sadly forgotten form now.... I "love" this book!

Confronter un scientifique et un philosophe sur les neurosciences, leurs résultats, leurs projets, leur capacité à soutenir un débat sur la morale, sur les normes, sur la paix, tel est l'objet de ce livre. Le débat d'idées est trop rare en France. Affirmations péremptoires, critiques unilatérales, discussions incompréhensibles, dérisions faciles ne cessent d'encombrer le terrain sans souci pour des arguments qui, avant d'être convaincants,aspirent à être tenus pour plausibles, c'est-à -dire dignes d'être plaidés. Vivre un dialogue totalement libre et ouvert (...) entre un scientifique et un philosophe constitue une expérience exceptionnelle pour l'un comme pour l'autre. " (P. R. et J. -P. C. ). Paul Ricoeur est professeur honoraire à l'université Paris-X et professeur émérite à l'université de Chicago. Il est l'auteur de très nombreux ouvrages, notamment "La métaphore vive", "Temps et Récit", "Soi-même comme un autre". Jean-Pierre Changeux est professeur au Collége de France et à l'Institut Pasteur, membre de l'Académie des sciences. Il est notammentl'auteur de "L'Homme neuronal", "Matiére à pensée" (avec Alain Connes), et "Raison et Plaisir". ". (shrink)

An eminent neurobiologist reflects on the human brain, connecting recent scientific findings with ideas from an array of other disciplines.

Sur quoi reposent les normes éthiques? Comment expliquer l’universalité de l’exigence morale chez les hommes en dépit des différences qui séparent les mœurs? Les sciences biologiques, à défaut de fonder une morale naturelle, peuvent-elles indiquer des voies de recherche? sur ce thème, Jean-Pierre Changeux, l’auteur de L’Homme neuronal, aujourd’hui président du Comité national d’éthique, a réuni des philosophes, des psychologues, des anthropologues, des juristes, des neurobiologistes dans le cadre d’un grand colloque organisé en 1991 par la fondation pour la recherche (...) médicale. Cet ouvrage présente une synthèse de ces travaux particulièrement novateurs en France. (shrink)

Aborde de nombreux thèmes, notamment : la vérité en mathématiques, la construction du vrai dans le développement cognitif de l'enfant, la procédure de Ramsey et le problème du réalisme scientifique, les relations de l'astrophysique et de la cosmologie avec l'observation.

« Toute activité se laisse discerner et définir dans la mesure où elle prend forme, où elle inscrit sa courbe dans l’espace et le temps. La vie agit essentiellement comme créatrice de formes. La vie est forme, et la forme est le mode de la vie » (Henri Focillon). Formes de la géométrie et du cosmos, formes de la vie et de la pensée, formes architecturales, musicales et littéraires, formes fixes ou métamorphoses : le concept de forme est omniprésent dans (...) les sciences et dans les arts. C’est à une exploration de cette notion de forme que le Collège de France a consacré en octobre 2011 son colloque multidisciplinaire de rentrée : sa définition en philosophie chez Platon et Aristote, ses applications en mathématiques et en astrophysique, en chimie et en biologie, ses conséquences en psychologie et en linguistique, en anthropologie, en droit et dans les arts. Ces débats ont été aussi l’occasion de se tourner vers des pensées où elle joue un rôle particulièrement important, comme le structuralisme de Claude Lévi-Strauss ou l’histoire de l’art d’André Chastel. Jean-Pierre Changeux est professeur honoraire au Collège de France, chaire de Communications cellulaires. Il a dirigé la publication de trois colloques précédents du Collège de France : La Vérité dans les sciences (2003), Gènes et culture (2003) et L’Homme artificiel(2007). Contributions de Antoine Compagnon, Claude Debru, Stanislas Dehaene, Mireille Delmas-Marty, Philippe Descola, Anne Fagot-Largeault, Marcel Hénaff, Michel Hochmann, Jean-Jacques Hublin, François-Bernard Mâche, Jean-François Mangin, Jean-Claude Pecker, Jacques Reisse, John Scheid, Jesper Svenbro. (shrink)

Que se passe-t-il dans le cerveau de l'artiste lorsque celui-ci crée? Quels mécanismes régissent l'activité cérébrale au moment de la contemplation d'un tableau? D'où vient cette étrange et si puissante émotion, le plaisir esthétique? Peut-on l'expliquer? Longtemps la création artistique est demeurée un mystère. Depuis une vingtaine d'années, cependant, grâce à l'apport des neurosciences et de la psychologie cognitive, loin de s'épaissir, le mystère peu à peu se dissipe. Explorateur du cerveau et grand collectionneur, c'est à une fantastique « aventure (...) philosophique» au cœur du processus créatif que nous convie Jean-Pierre Changeux, dans ce livre illustré par des chefs-d'œuvre peu connus de l'art français et étranger. (shrink)

The structure and behaviour of the acetylcholine receptor (AChR) is described, and the evidence that it is an allosteric protein is discussed. The genes for the AChR subunits are subject to a complex set of spatio‐temporal transcriptional controls during development of the motor endplate, and these findings are reviewed here. Finally, the biotechnological prospects suggested by the new data are noted.

One of the vastly exciting areas in modern science involves the study of the brain. Recent research focuses not only on how the brain works but how it is related to what we normally call the mind, and throws new light on human behavior. Progress has been made in researching all that relates to interior man, why he thinks and feels as he does, what values he chooses to adopt, and what practices to scorn. All of these attributes make us (...) human and help to explain art, philosophy, and religions. Motion, sight, and memory, as well as emotions and the sentiments common to humans, are all given new meaning by what we have learned about the brain. In an introductory essay, Vernon B. Mountcastle traces the progress made in brain science during this century. Gerald M. Edelman touches upon features of the brain that challenge the picture of the brain as a machine. Semir Zeki discusses artists and artistic expression as an extension of the function of the brain. Richard S. J. Frackowiak probes the functional architecture of the brain. Mark F. Bear and Leon N Cooper explore whether complex neural systems can be illuminated by theoretical structures. Jean-Pierre Changeux sheds light on the knowledge gained in recent years concerning the neurobiology and pharmacology of drug action and addiction. Alexander A. Borbuly and Giulio Tononi ponder the quest for the essence of sleep, illuminating its complex dynamic process. George L. Gabor Miklos examines variations in neuroanatomies and sensory systems between individuals of the same species as well as variations across the evolutionary spectrum. Emilio Bizzi and Ferdinando A. Mussa-Ivaldi explain how scientists have approached the study of movement, the problems encountered, and the solutions proposed. Marcel Kinsbourne explores the unity and diversity in the human brain. In the concluding essay, Andy Clark points to recent work in neuroscience, robotics, and psychology that stresses the unexpected intimacy of brain, body, and world, supporting his belief that the mind is best understood as a brain at home in its proper bodily cultural and environmental niche. The breadth and scope of subjects covered in this volume attest to the extraordinary progress taking place in the study of the brain. This brilliant collection of essays by those at the forefront of research in this area will be of interest to all those interested in human behavior. Gerald M. Edelman is director of the Neurosciences Institute and chairman of the Department of Neurobiology at the Scripps Research Institute. Jean-Pierre Changeux is professor at the Collbge de France and the Institute Pasteur. (shrink)