Social cognition in autism is associated with the neurodevelopment of the posterior superior temporal sulcus

Objective: The posterior superior temporal sulcus (pSTS) plays a critical role in the 'social brain'. Its neurodevelopment and relationship with the social impairment in autism spectrum disorders (ASD) are not well understood. We explored the relationship between social cognition and the neurodevelopment of the pSTS in ASD. Method: We included 44 adults with high-functioning ASD and 36 controls. We assessed their performances on the 'Reading the mind in the eyes' test (for 34 of 44 subjects with ASD and 30 of 36 controls), their fixation time on the eyes with eye tracking (for 35 of 44 subjects with ASD and 30 of 36 controls) and the morphology of the caudal branches of the pSTS (length and depth), markers of the neurodevelopment, with structural MRI. Results: The right anterior caudal ramus of the pSTS was significantly longer in patients with ASD compared with controls (52.6 mm vs. 38.3 mm; P = 1.4 x 10(-3); Cohen's d = 0.76). Its length negatively correlated with fixation time on the eyes (P = 0.03) in the ASD group and with the Reading the mind in the eyes' test scores in both groups (P = 0.03). Conclusion: Our findings suggest that the neurodevelopment of the pSTS is related to the ASD social impairments.