サッカードに伴う連続点滅刺激の見かけの刺激の発生理由の考察

Abstract

Subjects were placed in complete darkness and asked to elicit a saccade from a repeatedly flashing stimulus (500 Hz) in the center of their visual field to a saccade target located 10 deg to the right of the stimulus. The stimulus produced a phantom flash array in the direction of the saccade. The stimulus was extinguished or was changed in color after the onset of the saccade. The subjects reported the perceived position of the rightmost phantom flash of the array. The time course of the perceived positions suggested that the degree of mislocalization of each phantom flash depended on the time from saccade onset in the case where stimulus flashing started before saccade onset or from the beginning of stimulus flashing. Our previous study suggested that the degree of mislocalization depends on the attended position during the saccade. Considering the previous study, the results in the present study suggested that the rightmost phantom flash position indicates the degree of the attention shift from saccade onset or appearance of the flashing stimulus until extinction of the stimulus.