一川 誠

Abstract We examined the properties in orienting visual attention that are triggered by social cues (eye gaze or pointing finger) and nonsocial cues (an arrow). Particularly, we investigated whether the mental state of others would be modulated by any social cue. We presented an occluder between the cue and target to manipulate the mental state of an agent in cues (i.e., whether the agent is aware of the target). For Experiment 1, the reaction time (RT) to detect the target was prolonged when the target side was occluded only in the gaze‐cue condition, but not for the arrow or the pointing finger. For Experiment 2, the RT of a discrimination task, which demanded greater cognitive demand, was not prolonged for any cue type. These results suggest that the mental state attribution for the agency of the cue, which is affected by an occluder, is specific to the gaze cue, and suggest that it is under top‐down control that requires cognitive resources.

The perceptual simultaneity range for two diotically presented tones increases with decreasing frequency separation of the two tones from approximately 0.5 Bark. As the present study of two frequency regions shows, this effect is not observed when the two tones are not presented to the same ear, i.e., presented dichotically. Since the increase in simultaneity is only observed when the tones are presented to the same ear, it is possible that it reflects the time-frequency uncertainty within a cochlear filter.