Hvordan gir hjernen opphav til bevissthet?

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Ved Stanslas Dehaene, Collège de France, Paris

onsdag 6. november 2013, kl. 14:00

Sal: Nedjma

Arrangør: Det Norske Videnkabs-Akademi of Forum For Bevissthesforskning

Inngang: Gratis

Programme:
14.00 – 14.05 Opening/Welcome, by Professor Kirsti Strøm Bull, President of The Norwegian Academy of Science and Letters
14.05– 14.15 Introduction of Stanislas Dehaene by Johan F. Storm, Neurophysiogy, University of Oslo
14.15– 15.15 Lecture by Dr. Stanislas Dehaene: Signatures of conscious processing in the human brain (60 min)
15.15– 15.30 Coffee break (15 min)
15.30– 16.30 Panel discussion and questions from the audience

Chair: Nils Chr. Stenseth, Professor at the University of Oslo (CEES),
and Vice President of TheNorwegian Academy of Scienceand Letters

Panel:
Stanislas Dehaene
, Collège de France, Paris
Johan F. Storm, Neurophysiology, Medical Faculty, University of Oslo
Thomas Espeseth, Inst. of Psychology, University of Oslo
Sebastian Watzl, CSMN, Philosophy, University of Oslo

Sponsored by The Norwegian Academy of Scienceand Letters, and SERTA CDAB, UiO

Les mer om arrangementet her

Bevissthetsforskning – en introduksjon
Kan vår bevissthet forklares ut fra hjerneprosesser?
Vi vet alle hva bevissthet er: Vår opplevelse av å sanse, føle og tenke – det som forsvinner når vi faller i dyp, drømmeløs søvn, narkose eller koma, og som kommer tilbake når vi våkner opp. Også når vi drømmer har vi bevissthet, idet vi opplever noe subjektivt, om enn på en annen måte enn når vi er våkne.
Til tross for at bevissthet er et så uhyre sentralt fenomen for oss, det mest sentrale vil mange si, har vitenskapen hittil vært ute av stand til å finne en god forklaring. Det er tilsynelatende intet i dagens naturvitenskap som gir forventning om at fysiske og kjemiske prosesser i hjernen eller noe annet system skal gi opphav til subjektive opplevelser. Bevisstheten og det subjektive fremstår således som et totalt overraskende fenomen, uten noen fullgod, bredt akseptert forklaring innenfor vårt objektive verdensbilde. Hjerne-bevissthetsproblemet har vært diskutert i århundrer av filosofer og forskere uten klare gjennombrudd. Inntil nylig har det vært en utbredt oppfatning, også blant mange hjerneforskere, at det er nærmest umulig å studere dette med eksperimentelle og andre naturvitenskapelige metoder.  I senere år et det imidlertid vokst frem økt optimisme og interesse for bevissthetsforskning blant hjerneforskere, stimulert av nye, potente metoder. I 2002 erklærte Stanislas Dehaene og Jean-Pierre Changeux at hjerne-bevisshetsproblemet er ”Den ultimate intellektuelle utfordring for vårt nye årtusen”. Siden da har det vært gjort lovende fremskritt i teoretisk og eksperimentell forskning på dette områder. StanislasDehaene har bidratt vesentlig til dette, og vil redegjøre for dette i sitt foredrag. – J.F. Storm Forum for bevissthetsforskning

Abstract of Dr. Dehaene’s lecture
Understanding how brain activity leads to a conscious experience remains a major experimental challenge.
I will describe a series of experiments that probe the signatures of conscious processing. In these experiments, my colleagues and I ask whether a specific type of brain activity can be detected when a person suddenly becomes aware of a piece of information. We create minimal contrasts whereby the very same visual stimulus is sometimes undetected, and sometimes consciously seen. We then use time-resolved methods of electro- and magnetoencephalography to follow the time course of brain activity.
The results show that conscious access relates to a global burst of late synchronized activity (a cortical “ignition”), distributed through many cortical areas. We propose a theory of a global neuronal workspace, according to which what we experience as a consciousness is the global availability of information in a large-scale network of pyramidal neurons with long-distance axons.
This knowledge is now being applied to the monitoring of conscious states in non-communicating patients. Using real-time signal processing techniques, we believe that a few minutes of testing with simple sounds and two recording electrodes might suffice to determine whether a person is conscious.
Reference: Dehaene, S., & Changeux, J. P. (2011). Experimental and theoretical approaches to conscious processing. Neuron, 70, 200-227.

Biosketch of Dr. Stanislas Dehaene
Stanislas Dehaene is professor at the Collège de France, where he holds the chair of Experimental Cognitive Psychology. He directs the INSERM-CEA Cognitive Neuroimaging Unit at NeuroSpin in Saclay, south of Paris — France’s advanced neuroimaging research center. His research investigates the neural bases of human cognitive functions such as reading, calculation and language, with a particular interest for the differences between conscious and non-conscious processing. His main research findings include the discovery of automatic links between numbers and space, and of the role of the intraparietal sulcus in number sense; the operation of the “visual word form area”, a left occipito-temporal region which acquires the visual component of reading; and the identification of physiological responses unique to conscious processing, supporting the theory of a “global neuronal workspace” for consciousness.
He is the author of "The number sense" (1997/2010) and "Reading in the brain" (2009), and the editor of "The cognitive neuroscience of consciousness" (2001) and "From monkey brain to human brain" (2007). He is a member of the French and US Academies of Sciences and the Pontifical Academy of Sciences, and the recipient of the Dr. A.H. Heineken Prize in Cognitive Science (2009) and the McDonnell Centennial Award (1999).