Superior temporal sulcus

Social perception

Allison, Puce, and McCarthy reviewed evidence that this region responds to signals produced by the movements of others. The posterior part has attracted particular interest. It appears involved in perceiving where someone is looking and in interpreting how they move.

• Biological motion, including walking and gesture
• Movements of the eyes and mouth
• Goal-directed hand actions
• Combining sounds and sights, such as seeing and hearing speech

Language and theory of mind

Regions along the sulcus also respond during speech perception and language comprehension. A neighboring area at the temporoparietal junction is often activated when people think about the beliefs of others. The left and right hemispheres seem to differ in emphasis, with language generally more strongly left lateralized in most people, but how these areas relate to one another remains an open question.

One region or many?

Hein and Knight asked whether a single region can really serve so many functions. Their review suggested that the function of this area may vary according to the wider network active at the time. Interpretation of brain imaging has its own constraints: activation shows association with a task, not that a region is necessary for it. Differences reported in conditions such as autism have varied across studies, and the region should not be described as a dedicated social module.