Spatio-temporal effects in visual gap detection

The ability of the visual system to process temporal information is studied with regard to the interactions between temporal and spatial stimulus dimensions. A comparison of the results of two experiments indicate that the eye is able to discriminate temporal gaps in a train of visual flashes better when the flashes are spatially superposed then when they are dispersed. Thus, the inertial and integrating properties of the visual receptor seem, at first glance, to hinder the discrimination less than does spatial dispersion. However, an analysis of the results, using Levinson’s low-pass filter model, suggests that the increased discrimination is due to the recoding of the temporal stimulus information along a brightness dimension, and thus the true temporal properties of the visual system are probably better described by the dispersed rather than the overlapped condition. Other experiments are also reported that deal with related phenomena germane to the ability of human Ss to deal with the temporal information pattern of visual stimuli.