Abstract: 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.

Key words: Visual localization, Global processing, Local processing, Structure effect