Social Attention in 47,XXY (Klinefelter Syndrome): Visual Scanning of Facial Expressions Using Eyetracking.

Boys and men with an extra X chromosome (47,XXY, Klinefelter syndrome) are at risk for problems in social functioning and have an increased vulnerability for autism spectrum disorders (ASD). In the search for underlying mechanisms driving this increased risk, this study focused on social attention, that is, spontaneous orientation toward facial expressions. Seventeen adults with 47,XXY and 20 non-clinical controls participated in this study. Social attention was measured using an eyetracking method that quantifies the visual scanning patterns of faces expressing different types of emotions (happy, fearful, angry, neutral) and their varying intensity levels (25%, 50%, 75%, 100%). Overall, the group with Klinefelter syndrome fixated less on the eye region of faces when compared to controls (Cohen's d 1.4), and did not show the typical tendency, as was found in the control group, to first fixate on the eyes when presented with a face (Cohen's d 1.0). There was no significant effect of type or intensity of emotion. Shorter looking times toward eyes showed a borderline significant correlation with self-reports of poorer social functioning, with 29% explained variance. These findings suggest a reduced tendency to rapidly and automatically attend to the eyes of others in individuals with 47,XXY. This may have impact on more complex social-cognitive abilities that build upon this. In addition to studies of behaviorally defined disorders such as ASD, studying individuals with Klinefelter syndrome provide insight into mechanisms underlying various "at risk" pathways of social dysfunction and the factors that mediate this risk.