title: Impulsiveness in patients with bulimia nervosa: electrophysiological evidence of reduced inhibitory control.
abstract: OBJECTIVE
  Bulimia nervosa (BN) is associated with a deficit of self-regulatory control and impulsivity. The present study aimed to clarify whether an impaired inhibitory control due to hyperarousal underlies impulsivity in BN subjects.
  
  
  METHODS
  Event-related potentials (ERPs) were recorded in 17 female patients with BN and 17 healthy controls during a three-tone oddball task. ERP components related to inhibition of irrelevant distractor stimuli, as well as effortful processing, were analyzed. Standardized low-resolution electromagnetic tomography (sLORETA) was used to assess ERP source activity.
  
  
  RESULTS
  Compared to healthy controls, BN patients showed reduced amplitude and shorter latency of the N200 (N2), increased amplitude and shorter latency of the target slow wave (SW), and higher amplitude of the P300 for distractor stimuli (P3a) and for targets (P3b). sLORETA showed the following: (1) higher activity of the P3a generators in the left parietal cortex, bilateral precuneus and right frontal and anterior cingulate for distractor stimuli and (2) lower activity of the SW generators in the left medial frontal gyrus, bilateral superior frontal, anterior cingulate and cuneus for target stimuli. The reduction of the N2 latency was associated with the Barratt scores for impulsiveness.
  
  
  CONCLUSIONS
  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 attention and self-regulatory control, which may contribute to impulsive behaviors in BN.
authors.affiliation: Department of Psychiatry, University of Naples SUN, Naples, Italy.
authors.forename: Eleonora
authors.initials: E
authors.lastname: Merlotti
authors.forename: Armida
authors.initials: A
authors.lastname: Mucci
authors.forename: Umberto
authors.initials: U
authors.lastname: Volpe
authors.forename: Valentina
authors.initials: V
authors.lastname: Montefusco
authors.forename: Palmiero
authors.initials: P
authors.lastname: Monteleone
authors.forename: Paola
authors.initials: P
authors.lastname: Bucci
authors.forename: Silvana
authors.initials: S
authors.lastname: Galderisi
mesh_terms: D000328:Adult; D001143:Arousal / Q000502:physiology; D001921:Brain / Q000503:physiopathology*; D052018:Bulimia Nervosa / Q000150:complications / Q000503:physiopathology* / Q000523:psychology*; D016022:Case-Control Studies; D005072:Evoked Potentials, Auditory / Q000502:physiology*; D005260:Female; D006801:Humans; D007175:Impulsive Behavior / Q000150:complications / Q000503:physiopathology* / Q000523:psychology*; D009433:Neural Inhibition / Q000502:physiology*; D009483:Neuropsychological Tests; D012927:Social Control, Informal