立体视觉的心理物理和VEP比较研究

心理物理试验是研究立体视觉的主要方法。70年代VEP开始用于体视研究,并取得许多结果。由于VEP信号复杂,这些结果不能令人满意。本文使用心理物理试验和VEP对比方法对体视加以研究。我们的结果是:VEP波形中第一个正峰与刺激图形的亮度有关;N_2峰和P_3峰的潜伏期对判断体视存在与否有重要价值;本试验确定N_2峰潜伏期在体视存在时约为240ms—280ms,无体视存在时约为290ms—310ms;P_3峰潜伏期在体视存在时约为280ms—310ms,无体视存在时约为340ms—360ms;体视存在时的VEP与无体视存在时的VEP的互相关系数小于0.1;有体视的VEP其功率谱密度在8Hz附近有一峰;心理物理试验中使用强制选择得到的结果从VEP波形比较中可以确认是可靠的;有体视的VEP其N_2和P_3的潜伏期随视差变化呈现规律性改变。

COMPARISON OF PSYCHOPHYSICAL EXPERIMENTS AND VEPS IN STEREOPSIS RESEARCH

Psychophysical experiment is the main method in the study of stereopsis. YEP was first used in the study of stereopsis since the 1970's with much re- sult. As YEP is very complicated the results were not satisfactory. In this paper we compared psychophysical experiments and VEPs in the research of stereopsis. The results showed that the first positive peak of VEP related to brightness of the stimulus; latence of N2 and P3 are useful for determining stereopsis; the latence of N2 is about 240 to 280ms for stereopsis and latence of N2 for none stereopsis is about 290 to 310ms; the latence of P3 is about 280 to 310ms for stereopsis and the latence of P3 is about 340 to 360ms for none stereopsis; the coefficient of coherence of VEP between stereopsis and none stereopsis is below 0.1; the density of power spectrum for stereopsis has a peak of around 8hz; the results with forced choice in psychophysical expe- riments is fairly reliable; the latence of N2 and P3 for stereopsis shows regu- larity while disparity was changed.