Using the circumplex model of affect to study valence and arousal ratings of emotional faces by children and adults with autism spectrum disorders.

The affective circumplex model holds that emotions can be described as linear combinations of two underlying, independent neurophysiological systems (arousal, valence). Given research suggesting individuals with autism spectrum disorders (ASD) have difficulty processing emotions, we used the circumplex model to compare how individuals with ASD and typically-developing (TD) individuals respond to facial emotions. Participants (51 ASD, 80 TD) rated facial expressions along arousal and valence dimensions; we fitted closed, smooth, 2-dimensional curves to their ratings to examine overall circumplex contours. We modeled individual and group influences on parameters describing curve contours to identify differences in dimensional effects across groups. Significant main effects of diagnosis indicated the ASD-group’s ratings were constricted for the entire circumplex, suggesting range constriction across all emotions. Findings did not change when covarying for overall intelligence.