Individuals with anorexia processed the non-self- images in a manner similar to controls, suggesting that there is no fundamental disturbance in their brain’s ability to process images of bodies. The major differences emerged in how they processed their self-images. Whereas the controls showed active engagement of the brain’s attentional system and the insula when looking at the self-images, even when scanning the images as instructed, those with anorexia showed no such activation and appeared to be suppressing emotional and perceptual processing of the self information. The authors hypothesize that the reduced perceptual processing may “provide the basis for perceptual disturbance in relation to body shape” which AN patients with anorexia show, and “the insula inactivity [may be] the basis of failure of feedback to correct their self-image disturbance.” Read more below.
Brains of anorexia nervosa patients process self-images differently from non-self-images: an fMRI study.
School of Psychiatry, University of New South Wales, Sydney, Australia. email@example.com
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 co
mprised 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.