OJ 1-14 Disparity tuning of area V4 neurons differs when tested with dynamic random-dot stereograms or solid-figure stereograms
Takahiro Doi1, Seiji Tanabe1, Kazumasa Umeda2, Ichiro Fujita1
1Grad Sch Frontier Biosciences, Osaka Univ, Osaka, Japan, 2Grad Sch Engineering Science, Osaka Univ, Osaka, Japan
Neurons in the macaque visual area V4 are sensitive to binocular disparity in dynamic random-dot stereograms (RDSs) or solid-figure stereograms (SFSs). Because disparity change in an RDS does not accompany positional shifts in monocular images, subjects must use the stereo vision system to detect the change. Thus an RDS is useful for investigating the neural mechanism of stereo vision. However, RDS-like images are rare in natural scenes, while SFS-like images are common. Here we quantitatively analyzed disparity tuning of V4 cells, each tested with RDSs and solid bars. No correlation existed in the modulation amplitude, tuning sharpness, and preferred disparity between the tuning curves obtained with the two stimulus types. Disparity tuning curves tested with RDSs were sharper than those tested with SFSs. The results suggest that stereoscopic depth representations of RDSs and SFSs considerably differ in V4. 2004 Elsevier Science Ireland Ltd. and the Japan Neuroscience Society. All rights reserved.