MICROGENETIC PROCESS OF PERCEPTION OF SUBJECTIVE CONTOUR USING SELF-SUFFICIENT INDUCING PATTERN

To investigate the operation of two figural cues of ''alignment'' and ''incompletion'' in the perception of subjective contour, the microgenetic process of perception of subjective contour was analyzed. Two inducing patterns were used, one with both ''alignment'' and ''incompletion'' cues and another with only an ''alignment'' cue. The latter was a simplified version of the ''self-sufficient'' pattern presented by Kanizsa in 1979 which induced no subjective contour under usual observation. These two patterns were tachistoscopically exposed for 10 to 70 msec., and four subjects rated the clarity of subjective contour on 240 trials. As a result, the rated clarity of subjective contour in the pattern with only an ''alignment'' cue showed a slight ''inverted-U'' function with a peak at 30 to 40 msec. as the duration of exposure increased, while that in the pattern with both cues increased monotonically. It was shown that, even in the ''self-sufficient'' pattern which induces no subjective contour under usual observation, the processing toward perception of subjective contour was generated at the early stage of the microgenetic process. The results also agree with this author's previous finding that ''alignment'' is active earlier in the processing of subjective contour than is ''incompletion.''