Examining the neural correlates of incidental facial emotion encoding within the prefrontal cortex using functional near-infrared spectroscopy

Abstract

Previous neuroimaging research has implicated the prefrontal cortex (PFC) as a region of the brain that is vital for various aspects of emotion processing. The present study sought to examine the neural correlates of incidental facial emotion encoding, with regard to neutral and fearful faces, within the PFC. Thirty-nine healthy adults were presented briefly with neutral and fearful faces and the evoked hemodynamic oxygenation within the PFC was measured using 16-channel continuous-wave functional near-infrared spectroscopy. When viewing fearful as compared to neutral faces, participants demonstrated higher levels of activation within the right medial PFC. On the other hand, participants demonstrated lower levels of activation within the left medial PFC and left lateral PFC when viewing fearful faces, as compared to neutral faces. These findings are consistent with previous fMRI research, and suggest that fearful faces are linked to a neural response within the right medial PFC, whereas neutral faces appear to elicit a neural response within left medial and lateral areas of the PFC.