The role of extra-striate areas in conscious motor behavior: a registered report with Fast-Optical Imaging

Abstract

Disclosing the brain areas responsible for the emergence of visual awareness and their timing of activation represents one of the major challenges in consciousness research. In particular, isolating the neural processes strictly related to consciousness from concurrent neural dynamics, either related to prerequisites or post-perceptual processing, has long engaged consciousness research. In this framework, the present study aims at unraveling the spatio-temporal dynamics underlying conscious vision by adopting a distinctive experimental design in which both awareness and motor response are manipulated, allowing the segregation of neural activity strictly related to awareness from response-related mechanisms. The study included 32 participants. We employed a GO/NOGO detection task, in which participants responded or withheld responding according to the experimental condition. Critically, during the performance of the task, participants’ brain activity was recorded by means of Event-Related Optical Signal (EROS) technique, which provides accurate information about brain functions both from the temporal and spatial point of view within the covered regions, simultaneously. The combination of this experimental design with EROS recording enabled us to pinpoint the neural correlates underlying conscious vision and to disentangle them from processes related to the response. Extra-striate areas, specifically the Lateral Occipital Complex (LOC), showed greater awareness-related activity independently of motor response. Our findings support the view that LOC plays a key role as a proper correlate of visual awareness, rather than post-perceptual or response-related processes. They also show that awareness modulates motor activity only when a response is executed, clarifying how conscious perception influences downstream motor processing.