Individual differences in perceptual sensitivity to emotional human movement

Previous research has shown that typical adults demonstrate a heightened visual sensitivity to potentially threatening biological motion (Chouchourelou, Matsuka, Harber, & Shiffrar, 2006). Namely, typical adults are more sensitive to the presence of an angry point-light walker as compared to the presence of happy, fearful, sad, or neutral walkers. This is known as the anger-superiority effect. In a series of psychophysical studies, we asked whether individual differences in social skills influence the visual analysis of emotional human motion. Typical adults display a wide range of social abilities. Autism is a disorder that compromises social ability. Importantly, autism is a continuous disorder and autistic traits have been shown to exist in the general population. Given the associations between autism and dysfunction of the pSTS (a neural area involved in the visual detection of human movement; Boddaert et al., 2004), the amygdala (a neural area involved in emotion recognition and threat detection; Howard et al., 2000), and their interconnection, we examined the relationships between the magnitude of autistic traits in the general population and visual sensitivity to emotional human action. We predicted that individuals with excellent social skills (i.e., few autistic traits) would show levels of visual sensitivity to human motion that were emotion dependent, whereas individuals with poor social skills (i.e., more autistic traits) would show emotion-independent visual sensitivity to human motion.