Forming a negative impression of another person correlates with activation in medial prefrontal cortex and amygdala.

Neural correlates involved in the formation of negative impression from face were investigated using event-related functional magnetic resonance imaging and a partial conditioning paradigm. Eighteen normal volunteers underwent imaging while they viewed the faces of two unfamiliar individuals: one individual's face was partially accompanied by negative emotion but the other's was not. After the volunteers learned the relationship between the faces and the emotion, they formed a more negative impression of the person's face when the emotion was presented. Subtraction analysis of the individuals' neutral faces revealed activation in the dorsal anterior cingulate cortex and superior temporal sulcus, but this activity did not correlate with the change of impression from face. On the other hand, the response in the left amygdala negatively correlated with the change of impression from face in the first run. Time modulation analysis revealed that activity in the dorsomedial prefrontal cortex associated with negative emotion was the largest in the initial part of the acquisition. These results suggest that a negative impression from face may be formed by orchestrated activity in the dorsomedial prefrontal cortex, dorsal anterior cingulate cortex and amygdala, and that the activity has a prominent role in the initial acquisition of negative emotion.