An investigation of facial emotion recognition impairments in alexithymia and its neural correlates
Alexithymia is a personality trait that involves difficulties identifying emotions and describing feelings. It is hypothesized that this includes facial emotion recognition but limited knowledge exists about possible neural correlates of this assumed deficit. We hence tested thirty-seven healthy subjects with either a relatively high or low degree of alexithymia (HDA versus LDA), who performed in a reliable and standardized test of facial emotion recognition (FEEL, Facially Expressed Emotion Labeling) in the functional MRI. LDA subjects had significantly better emotion recognition scores and showed relatively more activity in several brain areas associated with alexithymia and emotional awareness (anterior cingulate cortex), and the extended system of facial perception concerned with aspects of social communication and emotion (amygdala, insula, striatum). Additionally, LDA subjects had more activity in the visual area of social perception (posterior part of the superior temporal sulcus) and the inferior frontal cortex. HDA subjects, on the other hand, exhibited greater activity in the superior parietal lobule. With differences in behaviour and brain responses between two groups of otherwise healthy subjects, our results indirectly support recent conceptualizations and epidemiological data, that alexithymia is a dimensional personality trait apparent in clinically healthy subjects rather than a categorical diagnosis only applicable to clinical populations.