The psychophysiological mechanisms of alexithymia in autism spectrum disorder

Accumulating evidence indicates that co-occurring alexithymia underlies several facets of the social-emotional difficulties common in individuals with Autism Spectrum Disorder (ASD). The mechanisms involved, however, remain poorly understood because measuring alexithymia relies heavily on self-report. To address this issue, carefully matched groups of individuals with ASD and comparison participants rated 70 emotion-inducing pictures on subjectively experienced arousal while skin conductance responses were monitored objectively. The results demonstrated reliable correlations between these subjective and objective measures, and in both groups around 25% of individual differences in this correlation (i.e. in emotion-relevant interoception) were accounted for by self-reported alexithymia. In the context of the wider literature, this suggests that alexithymia involves a disruption in how physiological arousal modulates the subjective experience of feelings in those with and without a diagnosis of ASD. Since mindfulness based therapies foster greater awareness of thoughts, feelings and bodily sensations, the findings also have implications for how the symptoms and consequences of alexithymia (e.g., anxiety) might be ameliorated