Patterns of perceived similarity cannot be generalized from long to short exposure durations and vice versa

It was found that the variables of form type (dots, lines, polygons) and axis of rotation (x, y, z) had no effect on perceived similarity in the long exposure conditions, but when inspection time was limited to 150 msec, both variables had a substantial impact.

Abstract

Subjects rated the perceived similarity between patterns and their 180-deg rotational variants. The stimuli, adapted from Halpern, Fishbein, and Warm (1979), were randomly generated dot patterns and line drawings and polygons generated from the dot patterns. Inspection time was varied in a between-subject design. As in the Halpern et al. (1979) study, it was found that the variables of form type (dots, lines, polygons) and axis of rotation (x, y, z) had no effect on perceived similarity in the long exposure conditions. However, when inspection time was limited to 150 msec, both variables had a substantial impact. This finding undermines the frequent practice of selecting stimuli for use in reaction time or other experiments with limited inspection time on the basis of similarity ratings gathered under typical free inspection conditions.