Social cognition modulates the sensory coding of observed gaze direction.

Gaze direction is an important social signal in both human and nonhuman primates, providing information about conspecifics' attention, interests, and intentions. Single-unit recordings in macaques have revealed neurons selective for others' specific gaze direction. A parallel functional organization in the human brain is indicated by gaze-adaptation experiments, in which systematic distortions in gaze perception following prolonged exposure to static face images reveal dynamic interactions in local cortical circuitry. However, our understanding of the influence of high-level social cognition on these processes in monkeys and humans is still rudimentary. Here we show that the attribution of a mental state to another person determines the way in which the human brain codes observed gaze direction. Specifically, we convinced observers that prerecorded video sequences of an experimenter gazing left or right were a live video link to an adjacent room. The experimenter wore mirrored goggles that observers believed were either transparent such that the person could see, or opaque such that the person could not see. The effects of adaptation were enhanced under the former condition relative to the latter, indicating that high-level sociocognitive processes shape and modulate sensory coding of observed gaze direction.