频差在立体视觉信息加工中的作用 Ⅱ、频差“克服”视差

双眼立体视觉机制至今不很清楚,存在不少争论,研究它具有深远意义。我们的兴趣是从心理物理、电生理和理论模型三方面开展工作,最终目标是试图搞清楚视觉立体信息处理类机制。本文主要利用心理物理学方法研究频差克差视差的问题。我们利用自己研制的一种多功能立体图形发生器产生左边为非均匀条纹、右边为均匀条纹的一系列具有不同视差的立体图对。在感知到“阶梯”后,用三种方法使得“阶梯”感变平:①改变均匀条纹的频率,②改变均匀条纹与被试的距离,③改变非均匀条纹与被试者的距离。从而实现了频差“克服”视差。我们的结果支持用频差来解释双眼倾斜现象,它使我们相信频差是视差在初级视系统中的表象形式。

DIFFREQUENCY FUNCTION IN THE INFORMATION PROCESSING OF BINOCURAR STEREOSCOPIC VISION I DIFFREQUENCY "SURMOUNTING" DISPARITY

The mechanism of binocular stereoscopic vision has not been clarified. It is the purpose of this research to study diffrequency surmonting disparity. "Stair" perception were obtained by stereoscopically viewing two scenes of gratings, one of which was with even distributed gratings and the other was with uneven distributed gratings. So, disparities existed between these two scenes. Three psychophysical methods of changing dif frequencies were used to see if "stair" can be perceived as a smooth plane without depth tilt, in other words, if diffrequency can surmount disparity. The results indicate that when diffre-quency equals zero, the fused gratings seems as a frontal plane parallel to the observer, even if there exist disparities. It suggests that diffrequency is the main cue of binocular tilt effect and represents disparity in primary visual syste m .