Abnormalities in neural processing of emotional stimuli in Williams syndrome vary according to social vs. non-social content.

Williams syndrome (WS) is a rare genetic disorder caused by the deletion of approximately 25 genes on chromosome 7q11.23 and is characterized by both hypersociability and increases in specific phobia and anticipatory anxiety regarding non-social entities or circumstances. Alterations in amygdala reactivity and prefrontal regulation consistent with the observed behavioral pattern of social versus non-social abnormalities have been previously demonstrated in individuals with WS (Meyer-Lindenberg et al., 2005). However, in that study, the social stimulus (faces) matching task was more difficult than the non-social scene (IAPS stimuli) matching task, making it impossible to disambiguate the relative contributions of task difficulty and stimulus type (social versus non-social). In the present study, we examined the performance of the same group of participants with WS and normal IQs during a more cognitively demanding task using the same scene stimuli as in the prior study. Confirming previous findings, the results indicated (a) a differential response of prefrontal regions as a function of task difficulty and (b) a persistently increased activation of the amygdala to non-social scenes by individuals with WS regardless of cognitive load. These data provide further evidence of disruption in amygdala-prefrontal circuitry in individuals with WS. Copyright (c) 2009. Published by Elsevier Inc.