Activation of the Right Inferior Frontal Cortex During Assessment of Facial Emotion

TLDR

We measured regional cerebral blood flow with PET to identify brain regions involved in assessing facial emotion. We asked right‑handed normal subjects to evaluate facial emotion, attractiveness, and background color, then compared the resulting brain activity across conditions. The right inferior frontal cortex, a triangular area in the right hemisphere, showed significant activation during facial emotion assessment, indicating hemispheric asymmetry in processing emotional communicative signals.

Abstract

We measured regional cerebral blood flow (rCBF) using positron emission tomography (PET) to determine which brain regions are involved in the assessment of facial emotion. We asked right-handed normal subjects to assess the signalers’ emotional state based on facial gestures and to assess the facial attractiveness, as well as to discriminate the background color of the facial stimuli, and compared the activity produced by each condition. The right inferior frontal cortex showed significant activation during the assessment of facial emotion in comparison with the other two tests. The activated area was located within a triangular area of the inferior frontal cortex in the right cerebral hemisphere. These results, together with those of previous imaging and clinical studies, suggest that the right inferior frontal cortex processes emotional communicative signals that could be visual or auditory and that there is a hemispheric asymmetry in the inferior frontal cortex in relation to the processing of emotional communicative signals.