Effects of stimulus duration, temporal delay, and complexity on the judgments of dot location.

The present study investigated how information on location was processed at an early stage of information processing by the task of recognizing dots presented briefly and followed by a masking stimulus. 8 subjects were asked on 1528 trials to recognize the positions of dots presented on a circumference. Effects of number of dots (1, 2, and 3), duration of presentation (36, 56, 200, and 500 msec.), and time delay (interval between the offset of display and the onset of recognition stimulus, 100 and 500 msec.) were examined. Analyses showed that the percentage of correct recognition increased with the duration of presentation and that the effect of duration decreased with the number of dots. Meanwhile, no significant effect was found for time delay. Consequently, with increased duration, the information on location is transferred to short-term visual memory. However, the ratio of transfer from iconic storage to short-term visual memory with duration varied with the complexity of visual stimulus.