03D-03 Characteristics of disparity tuning to dynamic random-dot stereogram in macaque area V4
Seiji Tanabe1, Takahiro Doi1, Kazumasa Umeda2, Ichiro Fujita1
1Graduate School of Frontier Biosciences, Osaka University, Toyonaka, Japan,
2Graduate School of Engineering Science, Osaka University, Toyonaka, Japan
We quantitatively examined the disparity tuning characteristics of a large population of neurons in V4 using dynamic random-dot stereograms. Any neuronal sensitivity to monocular visual features is averaged out with this stimulus, thus we isolated sensitivity to binocular disparity. Over half of the analyzed cells were selective for disparity (142/224, 63%). Most of these cells possessed a preferred disparity at a small crossed disparity, and were maximally sensitive to minute disparity increments near the fixation plane. The disparity tuning curves were mostly even symmetric. Our results suggest that neurons in area V4 are suited to detect fme 3D structures that protrude from background. Comparison with the disparity tuning properties of neurons in the middle-temporal area (MT) suggests a complementary role for stereo processing between V4 and MT.