Greater anterior insula activation during anticipation of food images in women recovered from anorexia nervosa versus controls

Abstract

Individuals with anorexia nervosa (AN) restrict food consumption and become severely emaciated. Eating food, even thinking of eating food, is often associated with heightened anxiety. However, food cue anticipation in AN is poorly understood. Fourteen women recovered from AN and 12 matched healthy control women performed an anticipation task viewing images of food and object images during functional magnetic resonance imaging. Comparing anticipation of food versus object images between control women and recovered AN groups showed significant interaction only in the right ventral anterior insula, with greater activation in recovered AN anticipating food images. These data support the hypothesis of a disconnect between anticipating and experiencing food stimuli in recovered AN. Insula activation positively correlated with pleasantness ratings of palatable foods in control women, while no such relationship existed in recovered AN, which is further evidence of altered interoceptive function. Finally, these findings raise the possibility that enhanced anterior insula anticipatory response to food cues in recovered AN could contribute to exaggerated sensitivity and anxiety related to food and eating.

Keywords: Functional magnetic resonance imaging (fMRI); Interoception; Neuroimaging.

FIGURE 1. Task design

Anticipation paradigm based on a previously published cueing task (Peper et al. 2009) using images of food and object images obtained by Uher et al. (Uher et al. 2003).

FIGURE 2. Group Effects during Food Anticipation (P<0.05, minimum cluster volume 1024mm³)

Axial images are displayed in Talairach Z coordinates (Talairach and Tournoux 1988). Control women (CW). Women recovered from anorexia nervosa (RAN).

FIGURE 3. Group Effects during Food Images (P<0.05, minimum cluster volume 1024mm³)

Axial images are displayed in Talairach Z coordinates (Talairach and Tournoux 1988). Control women (CW). Women recovered from anorexia nervosa (RAN).

FIGURE 4. Group (CW,RAN) by Condition (Food Anticipation, Object Anticipation) whole brain comparison

Regions of interest were thresholded at P<0.01 with a minimum cluster volume of 1024mm³. (A) One significant region of interest was identified in the right anterior inferior insula (1344mm³) characterized by (B) significantly increased response to anticipation of food, P=0.018, and significantly decreased response to anticipation of object images, P<0.001, in women recovered from anorexia nervosa (RAN) versus control women (CW). Post-hoc 2-tailed paired t-tests yielded significant within group and within condition differences. (C) The average difference of food and object pleasantness ratings showed a significant positive correlation with Food Anticipation – Object Anticipation percent signal change in this right anterior insula region in CW (r²=0.59) but not RAN (data not shown).