AS21-02 - Bulimia nervosa and impulsiveness: electrophysiological evidence of hyperarousal-related impairment of inhibitory processes

Abstract

Objectives Bulimia nervosa (BN) is associated with a deficit of self-regulatory control and impulsivity. The present study was aimed to clarify, using electrophysiological techniques, whether impulsivity in BN subjects is related to hyperarousal, which impairs inhibitory control. A poor modulation of emotional arousal might induce impulsive behaviors through this mechanism favoring binge eating as well as comorbidity with substance abuse. Methods Event-related potentials were recorded in 17 female patients with BN and 17 healthy controls, during a three-tone oddball task. ERP components related to response inhibition, effortful and automatic processing were analyzed. ERP topography and tomography were analyzed by means of the microstate and LORETA techniques. Results BN patients showed reduced amplitude and shorter latency of the N200; increased amplitude and shorter latency of the target SW; higher activity of the distracter P300 generators in left fronto-parietal-temporal cortex and bilateral cingulate; lower activity of the target SW generators in right frontal gyrus, left parieto-temporal regions, and bilateral cingulate. Discussion The observed electrophysiological abnormalities suggest a condition of hyperarousal, with impaired suppression of irrelevant stimuli due to abnormal cortical activation and reduced signal-to-noise ratio. Our findings point to functional abnormalities within a neural system that subserves self-regulatory control and reward, which may contribute to binge-eating and other impulsive behaviors in women with BN.