Effect of the localization of visual stimuli on the detection of temporal relations

The perception of simultaneity and temporal order of a pair of light stimuli is studied in dependence on their localization in the visual field. Four different modes of presenting the light stimuli on the screen were used: (1) both stimuli in the middle of the screen, immediately above the fixation point; (2) both stimuli in the left visual half-field, 8 deg. of arc to the left of the fixation point; (3) both stimuli in the right visual half-field, at the same distance from the fixation point; (4) one stimulus in the left and the other one in the right visual half-field, accordingly at 8 deg. of arc to the left or to the right of the fixation point. The duration of each of the pair of simultaneous or consecutive light stimuli was 100 ms. The percentage of correct responses to the presentation of simultaneous or consecutive pairs of light flashes was estimated. The experimental data suggest that the perception of simultaneity of two visual events depends on the spatial position of these events in the visual field.