The ability to infer others' thoughts, intentions, and feelings is regarded as uniquely human. Over the last few decades, this remarkable ability has captivated the attention of philosophers, primatologists, clinical and developmental psychologists, anthropologists, social psychologists, and cognitive neuroscientists. Most would agree that the capacity to reason about others' mental states is innately prepared, essential for successful human social interaction. Whether this ability is culturally tuned, however, remains entirely uncharted on both the behavioral and neural levels. Here we provide the first behavioral and neural evidence for an intracultural advantage (better performance for same- vs. other-culture) in mental state decoding in a sample of native Japanese and white American participants. We examined the neural correlates of this intracultural advantage using fMRI, revealing greater bilateral posterior superior temporal sulci recruitment during same- versus other-culture mental state decoding in both cultural groups. These findings offer preliminary support for cultural consistency in the neurological architecture subserving high-level mental state reasoning, as well as its differential recruitment based on cultural group membership.

To investigate the hypothesis that early visual processing of stimuli might be boosted by signals of emotionality, we analyzed event related potentials (ERPs) of twelve right-handed normal subjects. Gray-scale still images of faces with emotional (fearful and happy) or neutral expressions were presented randomly while the subjects performed gender discrimination of the faces. The results demonstrated that the faces with emotion (both fear and happiness) elicited a larger negative peak at about 270 ms (N270) over the posterior temporal areas, covering a broad range of posterior visual areas. The result of independent component analysis (ICA) on the ERP data suggested that this posterior N270 had a synchronized positive activity at the frontal–midline electrode. These findings confirm that the emotional signal boosts early visual processing of the stimuli. This enhanced activity might be implemented by the amygdalar re-entrant projections.