Excessive appetitive arousal in Prader-Willi syndrome.

This study focused on genetic and behavioural aspects of one important component of the motivation to eat - how appetitive arousal is elicited through the presentation of food-associated stimuli. Individuals with Prader-Willi syndrome, a genetic disorder associated with hyperphagia, and control participants completed a computerised response task in the presence of motivational stimuli. In controls, appetitive arousal was specific to particular stimuli. In contrast, individuals with PWS showed a non-specific pattern of arousal. Over-activation of the anticipatory motivation system may be one consequence of the genetic disorder in PWS.