Autonomic responses to dynamic displays of facial expressions in adolescents and adults with Williams syndrome.

The behavioral phenotype characteristic of Williams syndrome (WS) is marked by strong interest in social interaction, manifested in attention to human faces, empathy, approach behavior and social disinhibition, often coexisting with generalized anxiety. Despite their heightened social interest, people with WS show deficits in explicit emotion recognition tasks similar to those of people with other developmental disabilities. In the current study we explored whether individuals with WS show distinctive autonomic responsiveness to social-emotional information, using skin conductance response and heart rate measures. Autonomic activation was investigated in response to facial expressions of emotion in adolescents and adults with WS, compared to age-matched normal controls and to age-, IQ- and language-matched individuals with learning or intellectual disabilities (LID). Overall participants with WS were less electrodermally responsive to dynamically presented face stimuli than the age- and IQ-matched LID group, and showed more heart rate deceleration when viewing emotional faces than the controls. These findings, indicating hypoarousal but increased interest in response to the dynamic presentation of facial emotions in WS, are consistent with the behavioral profile of high approachability toward social stimuli in this population.