The 36th Congress of the International Union of Physiological Sciences (IUPS2009)

会場: Kyoto International Conference Center (ICC Kyoto)

著者:Takahiro Doi, Takahiro Okada, Ichiro Fujita
Lab Cognitive Neurosci, Osaka Univ, Toyonaka

タイトル:The Body Text of the Abstract:within 1300 characters including spaces Spatially selective integration of binocular disparities in fine depth perception

発表日:28 Jul., 2009

The acuity for perceiving stereoscopic depth is greatly improved when a reference stimulus is presented at a different location, suggesting that combining different binocular disparities over space is essential for stereoacuity. Here we examined how the brain spatially weighs and integrates binocular disparities in a fine depth discrimination task. To estimate the contribution of disparities at different locations in depth judgment, we introduced disparity noise to various locations within random-dot stereograms, which were otherwise binocularly correlated, consisting of test and reference planes. Subjects were required to report whether the test or reference plane was perceived as nearer. We then calculated the correlation between depth judgment and noise location. The estimated contribution or weight of binocular disparities was largest near the boundary between the test and reference planes and declined monotonically with distance from the border. At 4 deg from the boundary, the weight was 10% of the peak for stimuli with 3.5 deg eccentricity. We suggest that binocular disparities near the boundary contribute more to stereoacuity than those distant. The brain uses disparity signals only from near the boundary despite available signals over a wider area.