Effect of experience information on emotional word processing in alexithymia

Alexithymia is an at-risk personality trait that is associated with deficits in processing emotional words. However, little is known about whether the effect of emotional valence (neutral, positive, and negative) on word processing in alexithymia is related to individual differences in sensorimotor or affective information processing that is associated with alexithymia and experience information (sensorimotor vs. affective) that is denoted by words.

The present study performed two experiments to explore this issue. In Experiment 1, we orthogonally manipulated experience information that was denoted by neutral words. In Experiment 2, we orthogonally manipulated experience information that was denoted by valenced words (i.e., positive and negative). We asked two groups of healthy individuals with high scores (high alexithymic [HA] group) or low scores (low alexithymic [LA] group) on the 20-item Toronto-Alexithymia-Scale to complete a lexical decision task.

The results showed that emotional word processing in the HA group was modulated by a joint effect of valence and experience information, indicating that selective deficits in the processing of neutral and negative words were loaded more by sensorimotor information and that selective deficits in the processing of positive words were loaded more by affective experience compared with the LA group.

These findings shed a new light on emotional word processing in alexithymia and suggest that alexithymic deficits in the processing of emotional words should not be considered as being simply related to general or specific valence but rather related to experience information that is denoted by the meanings of words.