Abstract
Attentional direction can be different from visual direction. It has been shown that pupil response is affected by the luminance of attentional object. In addition, the frequency of pupil fluctuation has been shown to synchronize with that of luminance oscillation of attentional object. However the relationship between the degree of the synchronization and the change in the performance by the attentional state has not been investigated directly. In this research, we investigated the relationship between the power of the frequency component in the pupil fluctuation synchronized with the stimulus oscillation and the reaction time to the target stimulus, that is an index of the attentional state. We manipulated the attentional state of observers by changing the probability of the presentation location of target and measured the reaction time to detect the target and the pupil response. Results suggest that there is a correlation between the power of the frequency component in the pupil fluctuation synchronized with the stimulus oscillation and the attentional state.
