Anticipating intentional actions: The effect of eye gaze directionon the judgment of head rotation

摘要

Using a representational momentum paradigm, this study investigated the hypothesis thatjudgments of how far another agent's head has rotated are influenced by the perceivedgaze direction of the head. Participants observed a video-clip of a face rotating 60° towardsthem starting from the left or right profile view. The gaze direction of the face was eithercongruent with, ahead of, or lagging behind the angle of rotation. Following this, two staticfaces, at varying angles of rotation with respect to the end-point angle of the face in thevideo-clip, were presented simultaneously. The task of the participants was to decidewhich of the two heads was at an angle best resembling the angle of the end-point ofthe moving face. The critical test condition consisted of one test face oriented at 10° before,and the other at 10° after the end-point. The 'lagging behind' gaze condition elicited a sig-nificant underestimation of the rotation compared to the 'congruent' and 'ahead' gaze con-ditions. Participants did not exhibit similar biases when judging the rotation of severalnon-face control stimuli with visual features that mimicked different aspects of gaze direc-tion. The findings suggest that when the gaze direction of a perceived agent is incongruentwith the direction of the agent's head motion observers automatically utilise this discrep-ancy to adjust their inferences about the agent's intended heading direction.