Body image perception and sense of agency: notes from the alien hand experiment

Body image perception comprises stable and dynamic representational features. Here, we examined whether a stable body image (BI) measure correlates to a dynamic sense of agency (SoA) score. Moreover, we tested whether differential BI perception scores predicts SoA performance under sensory conflict conditions. A total of 21 university students (age M=25.9, SD=9.29) completed the Brazilian version of the Silhouette Figures Scale (SFS) and participated in The Alien Hand Experiment (TAHE). TAHE is a task that manipulates participants’ hand movement SoA. A Bayesian correlation matrix revealed substantial negative correlation probability between BI perception and SoA confidence in accuracy responses, specifically in experimental conditions where agency was manipulated. Based on the SFS scores, participants were divided into groups with and without evidences of BI distortion. Bayesian Independent Samples T-Tests evidenced substantial differential probability between groups. Analyzes confirmed lower SoA confidence among subjects with BI distortion greater than ±3 kg/m². La percepción de la imagen corporal comprende características representativas estables y dinámicas. Aquí examinamos si una medida estable de la imagen corporal (IC) correlaciona con el senso de agencia (SA) de movimientos corporales. Un total de 21 estudiantes universitarios (M=25,9, DP=9,29) completaron la versión brasileña de la Escala de Figuras de Siluetas (EFS) y participaran en el Experimento de la Mano Alienígena. Una matriz de correlación bayesiana reveló una probabilidad de correlación negativa sustancial entre IC y la confianza en SA, específicamente en las condiciones experimentales donde el SA fue manipulado. Con base en los escores de la EFS, los participantes se dividieron en grupos con y sin evidencias de distorsión de IC. Las comparaciónes de grupos evidenciaron una diferencia sustancial entre los grupos. Los análisis confirmaron una menor confianza en SA entre individuos con distorsión de IC mayor que ±3 kg/m². Body image perception comprises stable and dynamic representational features. Here, we examined whether a stable body image (BI) measure correlates to a dynamic sense of agency (SoA) score. Moreover, we tested whether differential BI perception scores predicts SoA performance under sensory conflict conditions. A total of 21 university students (age M=25.9, SD=9.29) completed the Brazilian version of the Silhouette Figures Scale (SFS) and participated in The Alien Hand Exper