In primates, neural processing of motion information starts at V1 layer 4, where many directional selective cells are found. In V2, directional selective cells are mostly found in thick stripes. The functional role of these V2 directional cells, however, is not well understood. Given the known role of V2 in real and illusory contour processing, we studied the possibility that motion cues may contribute to encoding of visual contours in V2.
Using intrinsic optical imaging technique, we imaged V1 and V2 response to moving stimuli (gratings and random dots) in awake, behaving monkeys. Our preliminary results showed that: 1) V2 thick stripes have higher motion sensitivity than thin or pale stripes. 2) Directional selectivity in thick stripes is organized in a topographic pattern. 3) V2 orientation domains respond to the motion boundaries in a similar way as to the luminance boundaries (cue-invariance). Based on these and other findings, we suggest a new view of V2's role in form and motion processing.