Neural substrates of the ability to recognize facial expressions: a voxel-based morphometry study.

The recognition of facial expressions of emotion is adaptive for human social interaction, but the ability to do this and the manner in which it is achieved differs among individuals. Previous functional neuroimaging studies have demonstrated that some brain regions, such as the inferior frontal gyrus (IFG), are active during the response to emotional facial expressions in healthy participants, and lesion studies have demonstrated that damage to these structures impairs the recognition of facial expressions. However, it remains to be established whether individual differences in the structure of these regions could be associated with differences in the ability to recognize facial expressions. We investigated this issue using acquired structural magnetic resonance imaging, and assessed the performance of healthy adults with respect to recognition of the facial expressions of six basic emotions. The gray matter volume of the right IFG positively correlated with the total accuracy of facial expression recognition. This suggests that individual differences in the ability to recognize facial expressions are associated with differences in the structure of the right IFG. Furthermore, the mirror neuron activity of the IFG may be important for establishing efficient facial mimicry to facilitate emotion recognition.