Learning the Rubber Hand Illusion: Implications for Dissociative PTSD Patients

The Rubber Hand Illusion (RHI) elicits the internalization of an external stimulus. To date, the RHI has been used to better understand body ownership in healthy controls and in specific pathologies, but has not yet been assessed in dissociative PTSD (d-PTSD) patients. Moreover, most studies having utilized a one trial experimental paradigm, did not follow the learning process of the RHI. The aim of this study was to assess the learning process of the RHI in d-PTSD patients, as compared to schizophrenia patients (SZs) and to healthy controls. Nineteen d-PTSD patients, 30 schizophrenia inpatients and 30 healthy controls underwent five different trials of the RHI over a two-week period. Significant interactions between group and trial emerged for start time and for illusion strength. D-PTSD patients showed an initial faster and more intense reaction to the illusion, compared to both other groups. However, throughout the learning process when no traumatic feelings arose, they corrected themselves and resembled the healthy controls. These findings might represent inappropriate activation and deactivation of both the Task Positive Network and the Default Mode Network in d-PTSD patients and may shed important light on neural functioning in d-PTSD patients.