Abstract
Being able to attend to the location others are gazing at is crucial to understand people's intentions. This orientation of attention by gaze has been studied using target detection tasks in which a central face cue gazing to the side precedes the appearance of a lateral target. Participants are faster to respond to the gazed-at location (congruent trials) than to the non-gazed at location (incongruent trials). Whether this gaze orienting effect (GOE) is modulated by facial expressions is still debated. A GOE enhancement has been reported with fearful compared to neutral faces and attributed to increased arousal or emotional valence.
In the present experiment, we compared the effects of fearful and surprised expressions, previously unstudied, on the GOE at the behavioral and neural level, using the ERP technique. In a classic target detection task, dynamic faces with averted gaze and displaying fear, surprise or no expression, were presented to 20 participants. The GOE was found for all emotions on reaction times. However compared to neutral faces, the GOE was significantly enhanced when the target was preceded by fearful and surprised faces, for which it did not differ. At the ERP level, an enhanced P1 amplitude in response to the target was found for congruent compared to incongruent trials for all emotions.
Thus, greater allocation of attentional resources at the gazed-at location was found for fear and surprise compared with neutral emotions only on reaction times. It remains possible that a differential emotional effect would be seen on ERPs in response to the cue, which we are currently investigating.
CIHR, CRC program, CFI and ORF.