Perceptual Science Series
Note: Talk time is at 1:00 pm for THURSDAY, May 15
Raymond van Ee
The Helmholtz Institute, Utrecht University, The Netherlands
Conscious Bi-Stable Depth Perception: Bayesian Modeling, Eye Movements, and Effort of Will
Conscious perception seems to be intimately linked to will-power. We studied voluntary control in perception by exposing the visual system to an ambiguous depth stimulus. Observers estimated the orientation of a grid in 3D space. Monocular- and binocular-specified grid orientations were independently varied across stimulus presentations. Observers perceived only one orientation when the two specified orientations had the same sign. More interestingly, observers were able to select either a monocular- or a binocular-dominated percept when the two specified orientations had opposite signs. Moreover, observers were able to flip at will between the two percepts in a relatively well-controlled way, implying that conscious vision can be studied physiologically (neurophysiology, fMRI) in a well-controlled way. To understand the underlying mechanisms we developed a Bayesian model.