Decoding the Time Course of Conscious and Unconscious Operations
Thursday, 12 March 2015,
19:00 - 20:20
Subject Area: Neuroscience
Parsing a cognitive task into a sequence of successive operations is a central problem in cognitive neuroscience. A major advance is now possible thanks to the application of pattern classifiers to time-resolved recordings of brain activity (electro-encephalography [EEG], magneto-encephalography [MEG], or intracranial recordings). The method determines precisely when a specific mental content becomes explicitly represented in brain activity. Most importantly, how the trained classifier generalizes across time and experimental conditions sheds light on the temporal organization of information-processing stages. I will illustrate these ideas using several MEG+EEG experiments in which temporal decoding is used to track the fate of conscious and unconscious stimuli in the brain. Decoding clarifies the time course of several classical phenomena such as masking, blindsight, attentional blink, and psychological refractory period. All of these paradigms give converging results, suggesting that conscious perception is associated with the late formation of a distributed and metastable neural assembly that encodes the current subjective state of mind.
Stanislas Dehaene has dedicated his career to exploring uniquely human cognitive functions. He pioneered the field of numerical cognition, identifying the regions of the brain that are responsible for the so-called “number sense.” He has more recently brought his mathematical expertise to bear on the subject of consciousness, developing a computational model that links the subjective conscious experience with its neural correlates. In 2003, he was a co-recipient of the Fondation Louis D. Award of the Institut de France, and he is a 2014 awardee of the prestigious Brain Prize.
Read more about Stanislas Dehaene.