Eye contact with neutral and smiling faces: Effects on autonomic responses and frontal EEG asymmetry

In our previous studies we have shown that seeing another person live with a direct vs. averted gaze results in enhanced skin conductance responses (scrs) indicating autonomic arousal and in greater relative left-sided frontal activity in the electroencephalography (asymmetry in the alpha-band power),associated with approach motivation. in our studies,however,the stimulus persons had a neutral expression. in real-life social interaction,eye contact is often associated with a smile,which is another signal of the sender's approach-related motivation. a smile could,therefore,enhance the affective-motivational responses to eye contact. in the present study,we investigated whether the facial expression (neutral vs. social smile) would modulate autonomic arousal and frontal eeg alpha-band asymmetry to seeing a direct vs. an averted gaze in faces presented live through a liquid crystal (lc) shutter. the results showed that the scrs were greater for the direct than the averted gaze and that the effect of gaze direction was more pronounced for a smiling than a neutral face. however,in this study,gaze direction and facial expression did not affect the frontal eeg asymmetry,although,for gaze direction,we found a marginally significant correlation between the degree of an overall bias for asymmetric frontal activity and the degree to which direct gaze elicited stronger left-sided frontal activity than did averted gaze. © 2012 pönkänen and hietanen.