How Do Looming and Receding Emotional Faces Modulate Duration Perception?

The direction of visual motion has been shown to affect the perception of interval duration; objects moving towards an observer (i.e., looming) are perceived to last longer than objects moving away (i.e., receding), and this has been explained in terms of arousal- or attention-based modulation. To dissociate the two competing accounts, we investigated how the influence of motion direction on duration perception is modulated by the emotional content of stimuli. Participants were given the temporal bisection task with images of emotional faces (angry, happy, and neutral) presented in a static (Experiment 1) or dynamic (Experiment 2) display. In Experiment 1, we found no influence of facial emotion on perceived duration. In Experiment 2, however, looming (i.e., expanding) stimuli were perceived as lasting longer than receding (contracting) ones. More importantly, we found an interaction between participant-rated arousal to faces and motion direction: The looming/receding asymmetry was pronounced when the stimulus arousal was rated low, but this asymmetry diminished with increasing arousal ratings. Thus, looming/receding temporal asymmetry seems to be reduced when arousing facial expressions enhance attentional engagement.