Your body, my experience: A systematic review of embodiment illusions as a function of and method to improve body image disturbance.
Jade Portingale, Isabel Krug, Hermione Liu, Litza A. Kiropoulos, David Butler · Clinical Psychology Science and Practice · 2024
Body image disturbance (BID) is a core feature of eating disorders and body dysmorphic disorder, with embodiment illusions offering the potential for understanding and treating BID through manipulating multisensory integration processes underlying self-perception. This systematic review is the first to evaluate evidence on whether (a) varying BID levels (i.e., BID-related diagnoses or higher levels of BID symptomatology) impact susceptibility to embodiment illusions and (b) embodiment illusions can improve BID symptomatology. Thirty-two studies involving clinical and community samples met the inclusion criteria. Generally, individuals with higher BID showed greater susceptibility to embodiment illusions compared to those with lower/no BID (nine of 14 studies, 64.29%). Most studies (20 of 24, 83.33%) found embodiment illusions produced improvements in BID, with medium to large effects across both findings. However, methodological heterogeneity and nonvalidated measures limit conclusions. Overall, results suggest multisensory integration disturbances underpin BID, while embodiment paradigms show promise as therapeutic interventions. Specific population factors (e.g., clinical diagnosis) and illusion parameters (e.g., body part stimulated, stimulation synchrony) influenced effects and warrant further investigation to optimize embodiment illusion paradigms. Despite limitations, this review highlights embodiment illusions as a valuable approach for elucidating mechanisms of BID and developing novel adjunctive treatments for BID-related conditions targeting multisensory integration deficits.