Behavioral, neuronal, and physiological facets of multidimensional body image in anorexia nervosa: a scoping review.

Body image is a core identity facet in anorexia nervosa (AN). Current literature outlines body image as a multidimensional construct, characterized by perceptual, cognitive, and emotional components, which explain how individuals perceive, think, and behave in relation to their body. The purpose of this scoping review is to uncover neuropsychological disturbances in AN related to body image by focusing on its different behavioral and neuronal assessments, aiming to provide a broad overview of common findings and limitations. Additionally, we explore the role of somato-sensory/somato-motor components and physiological markers underlying body image disturbances, which have not been extensively examined in previous studies. Literature screening was performed across three databases (PubMed, PsycINFO, Scopus). We classified behavioral, physiological, and neuroimaging studies according to their degree of involvement with body image dimensions and discussed the primary findings for each component. A total of 4015 studies were identified, of which 107 were eligible (84 behavioral and 23 neuroimaging studies) based on eligibility criteria, covering research from 1973 to 2024. Notably, of those which specified the following factors: 16 studies focused on the restrictive subtype (AN-r), two on the binge-eating/purging subtype (AN-b/p), and 19 examined both AN-r and AN-b/p; finally four on the atypical subtype; 11 on the weight-recovered state (WR) and three included also male participants. The mean age across all studies was 20.1 years (SD = 3.79). Our findings reveal that body image disturbances in AN are not limited to the overestimation of body size but also encompass cognitive, emotional, and somato-sensory aspects. A strong drive for thinness emerged as a prominent cognitive factor in maintaining the disturbance, along with altered autobiographical recall, executive function, and attentional biases toward body-related stimuli. Emotional regulation difficulties, altered interoceptive awareness, and distorted somato-sensory aspects-reflected in tactile and motor processes-were highlighted. In addition, increased autonomic reactivity to body image stimuli, indicating a sympathetic/parasympathetic imbalance, is supported by specific cortical-subcortical functional alterations. Our review emphasizes that body image distortion in AN should not be viewed merely as a perceptual deficit but rather as a complex cognitive-emotional and somato-sensory process.