Enhanced cortical processing of cardio-afferent signals in anorexia nervosa.

Objective: To assess cardiac interoception in anorexia nervosa (AN) using a multidimensional approach.

Methods: We assessed the physiological dimensions of cardioception, i.e. the peripheral signal itself (heart rate, HR, and heart rate variability, HRV) and its cortical representation (heartbeat evoked potentials, HEPs), and the psychological dimensions of interoceptive accuracy (heartbeat perception) and interoceptive sensibility (confidence ratings). Electroencephalogram (EEG) and electrocardiogram (ECG) were recorded concurrently during rest and while performing a heartbeat perception task in a sample of 19 female in-patients with AN (DSM-5) and 19 healthy control women (HC).

Results: HEPs, defined as mean EEG amplitude in a time window of 455-595 ms after the R-peak of the ECG, were significantly larger in the AN than in the HC group across conditions (p = .002, d = 1.06). There was a trend toward better heartbeat perception in AN, but no group differences in HR, HRV, and confidence ratings.

Conclusions: Individuals with AN showed an interoceptive profile of heightened cortical processing, a trend toward heightened interoceptive accuracy, and unaltered cardiac autonomic activation and interoceptive sensibility.

Significance: In terms of neurobiological models of AN, enhanced cortical representations of interoceptive signals might reflect a mechanism, which promotes fasting by alleviating negative body states.