Synchrony dynamics in monkey V1 predict success in visual detection.
Behavioral measures such as expectancy and attention have been associated with the strength of synchronous neural activity. On this basis, it is hypothesized that synchronous activity affects our ability to detect and recognize visual objects. To investigate the role of synchronous activity in visual perception, we studied the magnitude and precision of correlated activity, before and after stimulus presentation within the visual cortex (V1), in relation to a monkey's performance in a figure-ground discrimination task. We show that during the period of stimulus presentation a transition in synchronized activity occurs that is characterized by a reduction of the correlation peak height and width. Before stimulus onset, broad peak correlations are observed that change towards thin peak correlations after stimulus onset, due to a specific decrease of low-frequency components. The magnitude of the transition in correlated activity is larger, i.e. a stronger desynchronization occurs, when the animal perceives the stimulus correctly than when the animal fails to detect the stimulus. These results therefore show that a transition in synchronous firing is important for the detection of sensory stimuli. We hypothesize that the transition in synchrony reflects a change from loose and global neuronal interactions towards a finer temporal and spatial scale of neuronal interactions, and that such a change in neuronal interactions is required for figure-ground discrimination.
van der Togt
Chris
C
Department of Vision and Cognition II, The Netherlands Ophthalmic Research Institute, Meibergdreef 47, 1105BA Amsterdam, The Netherlands. c.vandertogt@ioi.knaw.nl
Kalitzin
Stiliyan
S
Spekreijse
Henk
H
Lamme
Victor A F
VA
Supèr
Hans
H
D000818:Animals; D001931:Brain Mapping / Q000379:methods*; D003344:Cortical Synchronization; D004193:Discrimination Learning / Q000502:physiology*; D005074:Evoked Potentials, Visual / Q000502:physiology*; D008253:Macaca mulatta; D010775:Photic Stimulation / Q000379:methods; D013223:Statistics as Topic; D014793:Visual Cortex / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology*