Social cognition and the superior temporal sulcus: implications in autism.

The most common clinical sign of autism spectrum disorders (ASD) is social interaction impairment, which is associated with communication deficits and stereotyped behaviors. Based on brain-imaging results, our hypothesis is that abnormalities in the superior temporal sulcus (STS) are highly implicated in ASD. These abnormalities are characterized by decreased grey matter concentration, rest hypoperfusion and abnormal activation during social tasks. STS anatomofunctional anomalies occurring early across brain development could constitute the first step in the cascade of neural dysfunctions underlying autism. It is known that STS is highly implicated on social perception processing, from perception of biological movements, such as body movements or eye gaze, to more complex social cognition processes. Among the impairments that can be described in social perception processing, eye gaze perception is particularly relevant in autism. Gaze abnormalities can now be objectively measured using eye-tracking methodology. In the present work, we will review recent data on STS contributions to normal social cognition and its implication in autism, with particular focus on eye gaze perception.