Successive versus Simultaneous Processes in the Recognition of Visual Patterns

Abstract

In earlier experiments with known nonverbal figures that subjects had to memorise, we found that, at the beginning of practice, recognition probability fell with increasing number of elements in a figure. Thus, the recognition process obeyed the principle of successiveness (Guriniene, 1993 Perception 22 Supplement, 50 – 51). In order to localise the successiveness at the lower levels of visual information processing, we investigated how the recognition probability for unknown patterns depended on their complexity. Test patterns were nonverbal geometrical figures consisting of four, five, six, seven, or eight vertical and horizontal line-segments. The sequence of each trial was as follows: a sound signal for attention fixation; the test pattern (10 ms); an individually determined interstimulus interval (20 – 125 ms); the masking pattern (200 ms); a pause (0 s, 0.5 s, 1.5 s, 2.5 s, or 4.5 s); three sample patterns. Subjects were asked to identify which one of the three sample patterns presented was the test figure.

No dependence of the recognition probability of unknown figures on their complexity was found. We suppose that, in our experimental situation, the feature extraction from the stimulus is a simultaneous process, but the matching of extracted features with information from long-term memory is carried out successively.