Neural dynamics of social emotion processing in alexithymia

Alexithymia (“no words for feelings”), a transdiagnostic risk factor for various psychiatric disorders, is characterized by an impaired ability of emotion processing and regulation. Difficulties in emotion processing are at the core of alexithymia, which are mediated by altered neural correlates and dynamics. Given that social functioning is a major aspect of psychiatric disorders, we investigated the domain of social emotion processing and focused on the neural dynamics underlying social emotion processing in alexithymia.

We first replicated impaired emotion processing (indexed by higher P2 amplitudes in EEG recordings of brain activity) and additionally revealed intact emotional multisensory integration in alexithymia (accompanied by intact N1 and N2 EEG responses). Importantly, we demonstrated social-specific impairments of emotion processing in alexithymia (accompanied by higher N2 amplitudes and stronger alpha oscillations). Considering the important role of eyes within the face, we further showed perceptive and affective impairments for emotive eye-region processing in alexithymia, subserved by abnormalities of N1 and frontal alpha asymmetry. Futhermore, we found intact emotion-cognition integration in alexithymia in a nonsocial context and atypical adaptation to volatility learning following fearful facial expressions (i.e., social context), suggesting that impairments of emotion-cognition interaction in alexithymia are possibly social-specific.

Our findings revealed impairments at early as well as later stages of social emotion processing in alexithymia and argued that deficient social emotion processing is at the core of alexithymia. This thesis contributes to the scientific understanding of neuropsychopathology of alexithymia and may aid the development of treatment strategies of alexithymia-related mental disorders.