Alexithymia and lateralized presentation of emotional faces

Abstract

We tested whether alexithymia involves a right hemisphere deficit or impaired interhemispheric transfer. In 2 studies of college students, we assessed alexithymia (Toronto Alexithymia Scale-20), tachistoscopically flashed prototypic emotional faces to right or left visual fields, and recorded accuracy and reaction time. In study 1, 64 subjects (20 men) saw happy, angry, or neutral faces in 96 trials and responded whether or not the face was "emotional" using their ipsilateral or contralateral hand. Although alexithymia predicted more errors in recognizing anger overall (t=.27, p=.O3) especially among women, alexithymia was unrelated to intra or interhemispheric effects. In study 2, 44 subjects (23 men) saw angry, fearful, sad, or happy faces in 128 trials and verbally reported the emotion. Although alexithymia was unrelated to the differential performance of the hemispheres, the sexes differed in alexithymia's relationship to overall accuracy. Among women, alexithymia predicted lower accuracy (r-.60, p=.OO4), but among males, alexithymia predicted higher accuracy (r-.48, p=.O2); these fmdings held for both hemispheres and all emotions. We find no support for alexithymia's relationship to intra or interhemispheric deficits in facial emotion processing, but alexitbymia may predict emotion recognition differently for the sexes.