Self-Control in Bulimia Nervosa

The Influences of Eating and Fasting on Inhibitory Control in Bulimia Nervosa: A Computational Neuroimaging Study

This study examines the influence of acute fasting and eating on self-control in adult females with and without bulimia nervosa (BN). Specifically, the study team is investigating whether differences in behavior and brain activation in response to computer tasks after fasting and after eating a meal could help to explain the symptoms of bulimia nervosa. Data will be collected using questionnaires and a technology called magnetic resonance imaging (MRI).

Treatment-resistant binge eating and purging may be perpetuated by self-control deficits linked to reduced activation in frontostriatal circuits. To date, however, neurocognitive studies of BN have not assessed the dynamic computational processes underlying inhibition or considered the fact that individuals with BN oscillate between two extremes-under-controlled and over-controlled intake. The proposed study combines neuroimaging with computational modeling to investigate the influences of acute fasting and eating (i.e., metabolic states) on how the brains of women with bulimia nervosa (BN) adaptively prepare for and exert inhibitory control. More specifically, the study has the following main objectives: 1) To determine whether eating and fasting affect adaptive inhibitory control and related frontostriatal activation abnormally in BN; 2) To identify associations of BN severity with state-specific frontostriatal activation and behavior.

Two participant groups (one with and one without bulimia nervosa) will be scanned using MRI after they have fasted and after they have consumed a standardized meal. The order of these two scans will be counterbalanced across groups.

Participants are randomly assigned (in even numbers across the two groups) to scan order: A. These participants are first scanned after 16 hours of fasting on one day, and are next scanned after a standardized meal on a second day. B. These participants are first scanned after a standardized meal on one day, and are next scanned after 16 hours of fasting on a second day.

Participants are randomly assigned (in even numbers across the two groups) to scan order: A. These participants are first scanned after 16 hours of fasting on one day, and are next scanned after a standardized meal on a second day. B. These participants are first scanned after a standardized meal on one day, and are next scanned after 16 hours of fasting on a second day.

Frontostriatal activation associated with the predicted likelihood that upcoming inhibition is needed (P(stop))

Frontostriatal activation associated with: inhibitory control prediction errors (signed and unsigned)

Frontostriatal activation associated with the predicted likelihood that upcoming inhibition is needed (P(stop))

The frequency of binge eating episodes, self-induced vomiting episodes, and fasting episodes as assessed by the Eating Disorder Examination (EDE). Frequency of episodes assessed with no minimum or maximum limit.

The prevalence of bulimia nervosa is substantially greater in women than in men. Moreover, prior research suggest that men and women show different neural response patterns during the engagement of inhibitory control, and that satiety differentially impacts the neural function of men and women.

Inclusion Criteria: Female Aged 18 to 35 years Currently between 85 and 130% of the expected weight for height Right-handed English-speaking Additional Inclusion Criteria for Women with Bulimia Nervosa: ° Meet DSM-5 criteria for bulimia nervosa Exclusion Criteria: Medical instability Ongoing medical treatment, medical condition, or psychiatric disorder that may interfere with study variables or participation Shift work Pregnancy, planned pregnancy, or lactation during the study period Allergy to any of the ingredients in or unwillingness to consume the standardized meal or unwillingness to drink water during the fasting period Any contraindication for fMRI

Individual participant data that underlie the results reported in this article, after deidentification (text, tables, figures, and appendices).

Investigators whose proposed use of the data has been approved by an independent review committee identified for this purpose.