Neural correlates of rapid reversal learning in a simple model of human social interaction.

Humans and other primates spend much of their time engaged in social interactions where a crucial ability is to decode face expressions and act accordingly. This rapid reversal learning has been proposed to be important in the relative evolutionary success of primates. Here we provide the first neuroimaging evidence that the ability to change behaviour based on face expression in a model of social interactions is not reflected in the activity in the fusiform face area, but is specifically correlated with activity in the orbitofrontal and anterior cingulate/paracingulate cortices. These brain regions are particularly involved in reversal learning, such that the activations described occurred specifically at the time of reversal, and were also found when different face expressions other than angry were used to cue reversal. The evidence that the orbitofrontal and anterior cingulate/paracingulate cortices are specifically activated at the time of reversal is important for understanding changes in affect and emotional processing in patients with lesions to these brain regions.