Perceptual Science Series
Neural Mechanisms of Perceptual Stability
Dr. Bart Krekelberg
Monday, February 22, 2010, 12:00pm - 07:00pm
Rutgers University, Center for Molecular and Behavioral Neuroscience
With every eye movement -- and we make 2 or 3 of these every second -- the world sweeps across the retina and moves to a different retinal location. Our research into perceptual stability investigates the neural mechanisms that allow us to not perceive these sweeps (saccadic suppression), and to know where things are in the world (stable position perception). I will present behavioral, imaging, and electrophysiological data that make the case that saccadic suppression is achieved in cortex, where we found different signatures of reduced visual sensitivity in a number of cortical areas (MT,MST,VIP,LIP). In these same areas, we also found eye position signals that are updated with every eye movement. Such an eye position signal, when combined with the retinal input can explain stable position perception. Interestingly, these eye position signals anticipated the real eye movements, which may explain why objects that are only briefly presented just before an eye movement are mislocalized. Taken together these data suggest that perceptual stability is not deferred to higher level processing, but achieved by neural mechanisms in early visual cortex.
Temporal Dynamics of Saccadic Suppression. Bremmer et al.
The Relationship between Saccadic Suppression and Perceptual Stability. Watson & Krekelberg
Cortical Contributions to Saccadic Suppression. Chahine & Krekelberg