刺激结构对视觉定位的影响

本实验采用多点定位作业,结合部分报告法,研究视觉刺激的整体结构对定位成绩的影响。所呈现的刺激为1、2、3或4个颜色点。其中2、3、4点刺激分别是直线、正三角形和正方形。结果发现,当呈现时间较长时,1点和2、3、4点的定位误差无显著差异。但是1点的定位反应时却显著少于2、3、4点。这提示出现视觉定位的结构效应。而当呈现时间较短时,却没有这种结构效应。实验还发现,这种结构效应并不因刺激结构的不同而有区别。

THE EFFECT OF STIMULUS STRUCTURE ON VISUAL LOCALIZATION

This experiment has been aimed to examine the effect of pattern of dots on visual localization. The stimuli randomly consist of one, two, three orfour dots of different colors, and the stimulus of two, three, four dots arespatially arranged so that they form a pattern of a line, an equilateral tri-angle and a square respectively. A microcomputer is engaged to present sti-muli and record the Ss' response. The brief presentation of an array is foll-bwed by a masking, then the Ss are asked to move mouse cursor to localizejust one dot of the array no matter how many dots had been presented. Ithas been found that when exposure duration is relatively long (250 MS), theaverage errors of localization for one, two, three and four dots are all atthe same level, while the RT at one dot is much shorter than that of multi-ple dots. The result suggests a structure effect in visual localization of mul-tiple dots. However, the effect disappears when exposure duration is redu-ced to 100 MS. The major aspects of the fect are discussed in relation to global and local processing.