Hjerne/bevissthetsforskning - Det Norske Videnskaps

Det Norske Videnskaps-Akademi og Forum for bevissthetsforskning
inviterer til åpent fellesmøte om:
Hjerne/bevissthets-forskning:
den 6.
november, 2013, med foredrag av
Prof. Dr. Stanislas Dehaene,
Collège de France and INSERM-CEA Cognitive Neuroimaging Unit, Saclay,
France
Signatures of conscious processing in the human brain
Time:
6 November, 2013, kl. 14.00-16.30
Place: Møterom Nedjma, 3. etasje, Litteraturhuset, Wergelandsveien 29, Oslo.
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 The Norwegian Academy of Science and 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 Science and Letters, and SERTA CDAB, UiO
http://theme.wordpress.com/credits/bevissthetsforum.com/
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-bevissthetsproblemet er ”Den ultimate intellektuelle utfordring for vårt nye
årtusen”. Siden da har det vært gjort lovende fremskritt i teoretisk og eksperimentell forskning på dette
området. Stanislas Dehaene har bidratt vesentlig til dette, og vil redegjøre for dette i sitt foredrag.
–J.F. Storm Forum for bevissthetsforskning
Abstract of Stanislas 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 longdistance axons.
This knowledge is now being applied to the monitoring of conscious states in noncommunicating 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).