Brains of anorexia nervosa patients process self-images differently from non-self-images: an fMRI study

The central disturbance in anorexia nervosa (AN) is a distorted body image. This perceptual error does not extend to judging others' body shapes. We used fMRI to examine if the brain processing of an image of self is different in the brains of AN patients. The sample comprised 10 patients with AN and 10 healthy control women. In a controlled epoch design, subjects were presented with images of self and non-self, matched for body mass index (BMI), in a counter-balanced fashion, and echoplanar images with blood oxygenation level dependent (BOLD) contrast were obtained on a 3T Philips scanner. Processing of non-self-images by control subjects activated the inferior and middle frontal gyri, superior and inferior parietal lobules, posterior lobe of the cerebellum and the thalamus. Patients had a similar pattern of activation with greater activation in the medial frontal gyrus. When the two groups were contrasted for the differential activation with self vs. non-self-images, control subjects had greater activation than patients in the middle frontal gyri, insula, precuneus, and occipital regions while the patients did not have greater activation in any region. AN patients had no significant regions of activation with self-images compared to baseline. We conclude that AN patients process non-self-images similarly to control subjects, but their processing of self-images is quite discrepant, with a lack of activation of the attentional system or the insula. Such discrepant emotional and perceptual processing may underlie the distortion of self-images by AN patients.