Affective-motivational brain responses to direct gaze in children with autism spectrum disorder.

BACKGROUND: It is unclear why children with autism spectrum disorders (ASD) tend to be inattentive to, or even avoid eye contact. The goal of this study was to investigate affective-motivational brain responses to direct gaze in children with ASD. To this end, we combined two measurements: skin conductance responses (SCR), a robust arousal measure, and asymmetry in frontal electroencephalography (EEG) activity which is associated with motivational approach and avoidance tendencies. We also explored whether degree of eye openness and face familiarity modulated these responses.
METHODS: Skin conductance responses and frontal EEG activity were recorded from 14 children with ASD and 15 typically developing children whilst they looked at familiar and unfamiliar faces with eyes shut, normally open or wide-open. Stimuli were presented in such a way that they appeared to be looming towards the children.
RESULTS: In typically developing children, there were no significant differences in SCRs between the different eye conditions, whereas in the ASD group the SCRs were attenuated to faces with closed eyes and increased as a function of the degree of eye openness. In both groups, familiar faces elicited marginally greater SCRs than unfamiliar faces. In typically developing children, normally open eyes elicited greater relative left-sided frontal EEG activity (associated with motivational approach) than shut eyes and wide-open eyes. In the ASD group, there were no significant differences between the gaze conditions in frontal EEG activity.
CONCLUSIONS: Collectively, the results replicate previous finding in showing atypical modulation of arousal in response to direct gaze in children with ASD but do not support the assumption that this response is associated with an avoidant motivational tendency. Instead, children with ASD may lack normative approach-related motivational response to eye contact.