Food Avoidance and Aversive Goal Value Computation in Anorexia Nervosa

Abstract

Anorexia nervosa (AN) is associated with food restriction and significantly low body weight, but the neurobiology of food avoidance in AN is unknown. Animal research suggests that food avoidance can be triggered by conditioned fear that engages the anterior cingulate and nucleus accumbens. We hypothesized that the neural activation during food avoidance in AN could be modeled based on aversive goal value processing. Nineteen females with AN and thirty healthy controls matched for age underwent functional magnetic resonance brain imaging while conducting a food avoidance task. During active control free-bid and computer-generated forced-bid trials, participants bid money to avoid eating food items. Brain activation was parametrically modulated with the trial-by-trial placed bids. During free-bid trials, the AN group engaged the caudate nucleus, nucleus accumbens, ventral anterior cingulate, and inferior and medial orbitofrontal cortex more than the control group. High- versus low-bid trials in the AN group were associated with higher caudate nucleus response. Emotion dysregulation and intolerance of uncertainty scores were inversely associated with nucleus accumbens free-bid trial brain response in AN. This study supports the idea that food avoidance behavior in AN involves aversive goal value computation in the nucleus accumbens, caudate nucleus, anterior cingulate, and orbitofrontal cortex.

Keywords: anorexia nervosa; eating disorders; fMRI; food avoidance; nucleus accumbens.

Figure 1

Correlation slope for the calorie content of the thirty-five food items shown and mean monetary bids placed across groups.

Figure 2

Brain response to low and high bid across the study groups in the caudate nucleus.

Figure 3

Higher left (L) nucleus accumbens free-bid goal value computation to avoid high caloric foods was associated with lower BMI and drive for thinness; nucleus accumbens aversive goal value computation was also associated with lower scores on the Intolerance of Uncertainty Scale (IUS), and Eating Disorder Inventory Emotion Dysregulation Subscale (EDI-ED).