CogniGron Seminar: Pieter Roelfsema (Netherlands Institute for Neuroscience, Amsterdam & Institut de la Vision, Paris) - "How neurons create conscious perceptions – a new route for restoring vision in blind individuals"

Why are some visual stimuli consciously perceived, whereas others remain subliminal? I will discuss how weak but simple stimuli reach access consciousness once they elicit a minimal level of activity in the frontal cortex, leading to their storage in working memory. For simple stimuli, the visual cortex apparently acts as a relay station that needs to pass the information to higher cortical areas but is not essential for report. However, we found that the perception of more complex visual stimuli relies on a more sustained interaction between visual cortex and associative brain regions, related to scene segmentation and visual attention. The implication is that the processes subserving conscious perception depend on the complexity of perceptual processing. These results pave the way for a genuine understanding of mechanisms for phenomenal and access consciousness in perception. Our findings also inspire new approaches to create a visual prosthesis for the blind, by creating a direct interface with the visual brain. I will discuss how high-channel-number interfaces with the visual cortex could be used in the future to restore a rudimentary form of vision in blind individuals.