Neural mechanisms of perceptive and affective processing of body stimuli in anorexia nervosa – are there developmental effects?

Stefanie Horndasch,Julie Rösch,Oliver Kratz,Anne Vogel,Hartmut Heinrich,Holmer Graap,Gunther H Moll,Arnd Dörfler,Clemens Forster

doi:10.1016/j.psychres.2020.112853

Abstract

Different components of body image processing seem to be reflected by different neural mechanisms. A core symptom of Anorexia nervosa (AN) is a disturbance of body image with correlates found on a neural level. The present study focuses on the neural processing of visual body stimuli of different weight categories in adolescent and adult AN patients.Thirty-three adolescents aged 12–18 years (15 AN patients, 18 control participants) and 36 adult women (19 AN patients, 17 control participants) underwent functional magnetic resonance imaging (fMRI) while performing a perceptive and an affective body image task involving photographic stimuli of women belonging to different BMI categories.Differential effects on activation, depending on the BMI of the women shown in the pictures, were found in frontal brain regions, the thalamus, the caudate and the fusiform gyrus. Group effects differentiating between AN patients and control participants were seen mainly in the caudate and insula. No significant developmental effect was seen.During a perceptive task, diminished activation of regions involved in perceptive and evaluative functions as well as emotional reasoning was seen in AN. During an affective task there was a tendency towards activation differences reflecting reduced ability of size estimation and impaired integration of visual and body perception with emotions.

Highlights

A core symptom of Anorexia nervosa (AN) is body image disturbance which is comprised of a behavioral, perceptual, cognitive and affective component (1-4)
During evaluation of the neural processing in an affective task there was a tendency towards activation differences reflecting reduced ability of size estimation and impaired integration of visual and body perception with emotions
For some regions that we considered to be of importance for the study the effects were only close to significance

Summary

Introduction

A core symptom of Anorexia nervosa (AN) is body image disturbance which is comprised of a behavioral, perceptual, cognitive and affective component (1-4). Several regions in the human cortex have been investigated as selectively processing the appearance of human bodies in healthy adults, e.g. the “extrastriate body area” in the occipitotemporal cortex (5) or the "fusifom body area" (6). In eating disorders (EDs) abnormal processing of body image, within a neural network for body perception, has been discussed (7) and investigated in several functional Magnetic Resonance. Differences between AN patients and healthy participants in body image processing, which have been found in the aforementioned studies, can be allocated to the following neural structures: In areas which have been described as selectively processing body pictures such as the fusifom body area and extrastriate body area (see above) either enhanced (10) or reduced (17, 18) activity was found in AN patients. Other studies reported similar levels of activity (9, 16, 20)

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