Emotion processing in alexithymia

Alexithymia refers to a lack of words for feelings and is considered to be a personality trait, leaving a person at risk for psychiatric and psychosomatic disorders. A reliable measure of alexithymia, the Toronto Alexithymia Scale-20 comprises three factors which reflect the affective, cognitive and behavioural characteristics of the disorder: difficulty in identifying emotion, difficulty in describing emotion and externally oriented thinking. The construct is associated with low positive affectivity (PA) and high negative affectivity (NA). The goal of these studies was to disentangle NA and alexithymia, and to investigate the structural or functional impairment in emotion processing. There were 46 male and 100 female volunteer subjects, aged between 17 and 55, who participated in three studies. Subjects discriminated between facial identity and facial expression given temporal constraint in Study 1, and between facial expression of emotion stimuli and neutral expressions given temporal constraint in Study 2. In Study 3 subjects colour named emotion and arousal words in a Stroop Task. In Study 1 all subjects were significantly more accurate in the identity condition. In Study 2 high alexithymics were significantly less accurate in the recognition of emotion given temporal constraint. Subjects with the greatest difficulty in describing emotions were the most impaired. There was a significant difference in the recognition of sad, angry and fearful stimuli. NA appeared to have a significant effect on perceiving differences in Study 1, but not in recognizing emotions in Study 2. While there were no between group effects in Study 3, there was a significant difference between conditions, with response time quickest for the baseline, and slowest for the arousal condition. These studies provide support for alexithymia as a viable construct. They help to disentangle NA and alexithymia, with NA having a significant effect in the attention stage of processing and alexithymia appearing to be a functional deficit, associated with difficulty in describing emotion, in the recognition stage of emotion processing. There appear to be overall differences in the accuracy of recognizing sadness, anger and fear. These studies also demonstrate that time, or temporal constraint, has a significant affect on emotion processing.