Estimation of brief time intervals presented in the right and left visual half-fields

The perception of visually presented duration is studied depending on the visual half-field in which the light stimulation has been presented. Light stimuli of the order of 200-1000 ms, of equal duration, divided by a 10 ms interval, were presented in random order, one in the left, the other in the right visual half-field. The subjects' task was to determine which of the pair of stimuli seemed longer. The response "equal in duration" was not allowed. It was found that two light stimuli of equal duration, consecutively presented in the left and right visual half-fields, are perceived as different owing to their time order. This difference reveals the effect of hemispheric differences in duration perception--the second of the pair of stimuli was reported by the subjects as longer in 70% of the cases when it was presented in the left visual half-field, while the second--in the right visual half-field was reported as longer in 60% of the cases.