No evidence of perceptual pseudoneglect in alexithymia

Abstract

Neuroscience research links alexithymia, the difficulty in identifying and describing feel-ings and emotions, with left hemisphere dominance and/or right hemisphere deficit. To provide behavioral evidence for this neuroscientific hypothesis, we explored the relationship between alex-ithymia and performance in a line bisection task, a standard method for evaluating visuospatial processing in relation to right hemisphere functioning. We enrolled 222 healthy participants who completed a version of the 20-item Toronto Alexithymia Scale (TAS-20), which measures alexi-thymia, and were asked to mark (bisect) the center of a 10-cm horizontal segment. The results doc-ument a significant rightward shift in the center of the line in participants with borderline and man-ifest alexithymia compared with non-alexithymic individuals. The higher the TAS-20 score, the greater the rightward shift in the line bisection task. This finding supports the right hemisphere deficit hypothesis in alexithymia and suggests that visuospatial abnormalities may be an important component of this mental condition.