Metacontrast Interference as Determined by a Method of Comparisons

Abstract

Interaction between successively presented visual stimuli with adjacent contours was investigated in order to see whether maximal metacontrast which appears typically at intermediate interstimulus intervals (ISI) is also obtainable when a method of comparisons is employed where several interference stimuli are shown, only one of which is preceded by a test stimulus. When such a method is used, for the two highly practiced Ss employed in this study data showed that the first stimulus was nearly always detectable at intermediate ISIs (50 to 100 msec.). However, when the duration of the test stimulus was very short, its detectability decreased as the interstimulus interval decreased, becoming maximal at the shortest interstimulus interval. Similar findings were obtained with the method of comparisons when the successively presented stimuli overlapped.