Retinotopic patterns of correlated fluctuations in visual cortex reflect the dynamics of spontaneous perceptual suppression.
While viewing certain stimuli, perception changes spontaneously in the face of constant input. For example, during "motion-induced blindness" (MIB), a small salient target spontaneously disappears and reappears when surrounded by a moving mask. Models of such bistable perceptual phenomena posit spontaneous fluctuations in neuronal activity throughout multiple stages of the visual cortical hierarchy. We used fMRI to link correlated activity fluctuations across human visual cortical areas V1 through V4 to the dynamics (rate and duration) of MIB target disappearance. We computed the correlations between the time series of fMRI activity in multiple retinotopic subregions corresponding to MIB target and mask. Linear decomposition of the matrix of temporal correlations revealed spatial patterns of activity fluctuations, regardless of whether or not these were time-locked to behavioral reports of target disappearance. The spatial pattern that dominated the activity fluctuations during MIB was spatially nonspecific, shared by all subregions, but did not reflect the dynamics of perception. By contrast, the fluctuations associated with the rate of MIB disappearance were retinotopically specific for the target subregion in V4, and the fluctuations associated with the duration of MIB disappearance states were target-specific in V1. Target-specific fluctuations in V1 have not previously been identified by averaging activity time-locked to behavioral reports of MIB disappearance. Our results suggest that different levels of the visual cortical hierarchy shape the dynamics of perception via distinct mechanisms, which are evident in distinct spatial patterns of spontaneous cortical activity fluctuations.
Department of Psychology, University of Amsterdam, 1018 XA Amsterdam, The Netherlands. T.H.Donner@uva.nl
Tobias H
TH
Donner
Dov
D
Sagi
Yoram S
YS
Bonneh
David J
DJ
Heeger
D000328:Adult; D001931:Brain Mapping; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009038:Motion; D009039:Motion Perception / Q000502:physiology*; D009903:Optical Illusions / Q000502:physiology; D010775:Photic Stimulation; D014793:Visual Cortex / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology*