FUNCTIONAL INTERACTIONS BETWEEN AREAS V1 AND V2 IN THE MONKEY

The role of feedback connections from area V2 to V1 was studied by rev ersible inactivation. When V2 was inactivated, the responses of some V 1 neurons to stimulation of the surround region were increased while r esponses to center stimulation were unchanged or decreased. Latencies to small flashing stimuli were also compared in areas V1 and V2. The d istributions in the two areas overlap largely, with a 10 ms shift betw een the two. Neurons of V1 and V2 that are driven by the magnocellular layers of the LGN are activated 20 ms earlier than neurons of the par vocellular stream.