Program Number: OS3P-4-01 Presentation Time: Friday, July. 21, 14:00 - 14:15
Spatial frequency tuning of disparity-selective neurons in macaque V4
Hironori Kumano1, Seiji Tanabe2, Ichiro Fujita2
1Grad. Sch. of Engineering Science, Osaka Univ., Osaka, Japan, 2Grad. Sch. of Frontier Biosciences, Osaka Univ., Osaka, Japan
To examine whether convergence across spatial frequency channels contribute to stereoscopic processing, we recorded single neuron activity from area V4 of awake, fixating monkeys. For each neuron tested, we first measured the spatial frequency tuning with sinusoidal gratings or two-dimensional (2-D) filtered noise images, and then examined the disparity tuning with both correlated and anti-correlated dynamic random-dot stereograms (RDSs). Neurons with broader spatial frequency tuning had more attenuated disparity tuning for anti-correlated RDSs. In a subset of V4 neurons, we analyzed responses to various combinations of binocular disparity and spatial frequency by using 2-D filtered noise stereograms. The disparity tuning of most V4 neurons was consistent across a range of spatial frequencies to which they were sensitive. We suggest that V4 neurons pool disparity signals across spatial frequency channels to create an unambiguous representation of stereoscopic depth.
Keywords: STEREOPSIS, VISUAL CORTEX, AWAKE MONKEY, ELECTROPHYSIOLOGY
Reserch Funds: Supported by grants from MEXT (17022025) and Takeda Science Foundation.