Seminar SCALab 27/02/2025

Nathan Faivre - Director of Research CNRS - Labatory LPNC of the Unviersity Grenoble Alpes

Title: Accounting for the temporal dynamics of perceptual consciousness

Abstract:

The contrastive study of perceptual consciousness mostly compares brain activity when a stimulus is detected and when it is not. Although powerful, this approach is binary and leaves out the temporal aspect of perceptual consciousness: a stimulus, once detected, remains conscious for a given duration with a potentially non-constant intensity profile. In recent years, we have developed a computational framework to account for the dynamics of perceptual consciousness via a mechanism of leaky evidence accumulation. I will summarise the results of several behavioural studies and stereo-electroencephalographic recordings that support our computational framework. Notably, I will show that the perceived duration of a visual stimulus at perceptual threshold corresponds to the duration for which accumulated evidence remains above a perceptual threshold, in relation to the activity of mid-fusiform neuronal populations. I will conclude by discussing the potential of our approach to characterise other subjective aspects of conscious perception beyond simple detection, including confidence and non-veridical percepts.