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.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
OTHER
Masking
SINGLE
Enrollment
100
16 hours of fasting
fed a standardized meal
neuroimaging with computational modeling
Center of Excellence in Eating and Weight Disorders at the Icahn School of Medicine at Mount Sinai
New York, New York, United States
Brain Activation Associated With P(Stop)
Frontostriatal activation modulated by the predicted need for inhibition (P(stop) (i.e., parametric modulation by p(Stop)), measured as the mean BOLD signal across voxels within the region of interest (ROI). Positive values indicate that neural activation increases as the predicted probability of needing to stop increases (i.e., stronger responses when stopping is predicted to be more likely), whereas negative values indicate that activation decreases as the predicted probability of needing to stop increases (i.e., greater activation when stopping is predicted to be less likely).
Time frame: after 16 hours of fasting and at 30 minutes after a standardized meal (as least 24 hours apart, but not more than 7 days apart)
Brain Activation Associated With Prediction Errors (Unsigned)
Frontostriatal activation modulated by unsigned inhibitory control prediction errors (i.e., parametric modulation by absolute prediction error magnitude), measured as the mean BOLD signal across voxels within the region of interest (ROI). Positive values indicate that neural activation increases with the magnitude of unsigned prediction errors (i.e., stronger responses to more surprising outcomes), whereas negative values indicate that activation decreases as unsigned prediction errors increase (i.e., relative deactivation for more surprising outcomes).
Time frame: after 16 hours of fasting and at 30 minutes after a standardized meal (as least 24 hours apart, but not more than 7 days apart)
Brain Activation Associated With Prediction Errors (Signed)
Frontostriatal activation modulated by signed inhibitory control prediction errors (i.e., parametric modulation by prediction error magnitude), measured as the mean BOLD signal across voxels within the region of interest (ROI). Positive values indicate that neural activation increases as signed prediction errors become more positive (i.e., stronger responses to the surprising need for control), whereas negative values indicate that activation decreases as signed prediction errors become more positive (i.e., stronger responses to the surprising lack of need for control).
Time frame: after 16 hours of fasting and at 30 minutes after a standardized meal (as least 24 hours apart, but not more than 7 days apart)
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Brain Activation Associated With Successful Inhibition
Frontostriatal activation associated with successful inhibition , measured as the mean BOLD signal across voxels within the region of interest (ROI) for the contrast of Successful Stop vs. Go trials. Positive values indicate activation associated with successful inhibition.
Time frame: after 16 hours of fasting and at 30 minutes after a standardized meal (as least 24 hours apart, but not more than 7 days apart)
Stop Signal Reaction Time (SSRT)
Behavioral performance on the stop signal task, as measured by stop signal reaction time calculated as mean go reaction time minus the stop-signal delay at 50% successful inhibition (SSD₅₀). Higher SSRT means longer latency before failed inhibition.
Time frame: after 16 hours of fasting and at 30 minutes after a standardized meal (as least 24 hours apart, but not more than 7 days apart)
Stop Signal Task Inhibition
Percent correct responses to stop trials on the Stop Signal Task measured by percent of stop trials on which participant successfully withheld a response (vs. failed to withhold response).
Time frame: after 16 hours of fasting and at 30 minutes after a standardized meal (as least 24 hours apart, but not more than 7 days apart)