Categorical perception of anger and disgust facial expression is affected by non-clinical social anxiety: an ERP study.Brain Res. 2007 Feb 09; 1132(1):166-76.BR
Anxiety has been associated with a bias for interpreting threatening information. Faces expressing anger seem to be more easily detected by socially anxious individuals than by non-anxious individuals. Similarly, disgust on a face may also reflect a negative social judgment. We tested the hypothesis that individuals displaying non-clinical social anxiety would be as sensitive to disgust as to anger interpretation by comparing individuals scoring high or low on the fear of social evaluation scale (FNE, Watson and Friend, 1969). Event-related potentials (ERP) were recorded in response to repetitions of a particular facial expression (e.g. anger) and in response to two deviating (rare) stimuli obtained by a morphing procedure, where one depicted the same emotion as the frequent stimulus, while the other depicted a different facial expression (e.g. disgust). The classic effect of categorical perception was reproduced: at a behavioral level, people detected more easily rare faces depicting a different emotion than faces depicting the same emotion. ERP results suggest that deviant faces depicting a different emotion evoked an earlier attentional N2b/P3a wave complex, together with an earlier and enhanced P3b. More interestingly, participants with non-clinical social anxiety manifested a reduced N2b wave when they had to detect a change in intensity of anger presentation. However, these individuals did not show facilitation to disengage from disgust when they have to detect angry faces, which was displayed by control participants. Implications and suggestions for further research about the role played by anger and disgust in psychopathology are outlined.