CBT Effects on Neural, Physiological, and Attentional Responses in Anorexia Nervosa

Condition(s) studied

Investigational drug(s) / intervention(s)

Cognitive-Behavioral Therapy: Manualized 12-week CBT protocol focused on reducing body image disturbance, distorted beliefs about food and appearance, and avoidance behaviors in individuals with anorexia nervosa. The intervention incorporates psychoeducation, cognitive restructuring, emotional regulation, food exposure, and body image work.

Study summary

This randomized controlled trial investigates the neurophysiological, physiological, and attentional effects of Cognitive-Behavioral Therapy (CBT) in individuals with restrictive-type anorexia nervosa (AN). The study compares two groups: one receiving a 12-week CBT intervention, and one placed on a waitlist (no active treatment during the study period). All participants undergo pre- and post-intervention assessments using electroencephalography (EEG), galvanic skin response (GSR), and eye-tracking while exposed to visual stimuli related to food, body image, and self-appearance. The primary outcomes include neural changes in attention and emotional processing (P300, LPP, frontal alpha asymmetry), physiological arousal (skin conductance), and visual attention biases (fixation duration and gaze distribution). The aim is to determine whether CBT leads to measurable improvements in neurobiological and attentional mechanisms related to body image disturbance and food-related anxiety in AN, contributing to biomarker-informed psychotherapy approaches.

Eligibility

Primary outcome measure(s)

• Change in EEG P300 amplitude in response to body image stimuli — aseline and Week 12
  P300 amplitudes will be extracted from EEG data during visual exposure to body image stimuli. Reduced amplitudes post-CBT are hypothesized to indicate reduced attentional salience and hyperfocus on appearance-related cues. P300 amplitudes will be extracted from EEG data during visual exposure to body image stimuli. Reduced amplitudes post-CBT are hypothesized to indicate reduced attentional salience and hyperfocus on appearance-related cues.
• Change in Late Positive Potential (LPP) amplitude to body and food stimuli — Baseline and Week 12
  LPP amplitudes will be measured during viewing of thin, overweight, and food-related images. A reduction post-CBT suggests decreased sustained emotional reactivity to distressing visual input.
• Change in frontal alpha asymmetry during self-image viewing — Baseline and Week 12
  Frontal alpha asymmetry (FAA), computed from EEG data, will be used to index emotional regulation. An increase in left-dominant FAA is expected post-CBT, reflecting enhanced emotional control and positive self-perception.
• Change in skin conductance response (SCR) to body and food stimuli — Baseline and Week 12
  Skin conductance responses will be measured via GSR during visual exposure to self-body, other-body, and food stimuli. Decreased SCR amplitudes post-CBT will indicate reduced physiological arousal and distress.
• Change in fixation duration on weight-related body areas — Baseline and Week 12 Baseline and Week 12
  Eye-tracking will assess gaze fixation duration on areas of interest (waist, thighs, stomach). Post-CBT reductions in fixation on these regions suggest reduced attentional bias toward body dissatisfaction zones.

Trial sites (1)

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