Neural Correlates of Conscious Motion Perception.
Frontiers in human neuroscience January 1, 2018 Gonzalo Boncompte, Diego Cosmelli
The neural signature of conscious perception is debated, with candidates including the P3b, Visual Awareness Negativity (VAN), and early components like P1. Most studies use static images, favoring ventral stream processing. This experiment isolated local motion, a dorsally processed feature, as the consciously perceived content. Using physical equality between Seen and Unseen conditions and minimal contrast differences, a P3b with wide centro-parietal distribution strongly correlated with stimulus detection, with larger magnitude for Seen vs. Unseen conditions consistently at the single subject level. VAN was undetectable, and P1 was absent. A N2pc component appeared in the 200-300 ms window, consistent with high attentional demands. Results extend P3b's role as a content-independent neural correlate of consciousness to visual motion perception.