People with posttraumatic stress disorder (PTSD) and its dissociative subtype show altered brain connectivity between the vestibular system—which integrates sensory information about body orientation—and cortical regions involved in self-awareness. Using resting-state fMRI, researchers compared 60 people with PTSD, 41 with the dissociative subtype, and 40 healthy controls. The PTSD and control groups had stronger connectivity between the vestibular nuclei and the parieto-insular vestibular cortex and dorsolateral prefrontal cortex than the dissociative subtype group. Greater depersonalization and derealization symptoms correlated with weaker connectivity in the right supramarginal gyrus. These findings suggest that disrupted vestibular multisensory integration may contribute to distinct symptom profiles in PTSD and its dissociative subtype.
In individuals with the dissociative subtype of posttraumatic stress disorder (PTSD), the rubber hand illusion (RHI) provokes complex and differentiated responses, including subjective distress, depersonalization, derealization, tonic immobility, increased physiological arousal, and flashbacks. The illusion was induced after both synchronous and asynchronous brushing. These findings suggest that the RHI acts as a strong provocation stimulus, eliciting individual patterns of symptom presentation related to body misrepresentation and altered body ownership. The paradigm may be useful for studying the neurophenomenology of body distortion in trauma-related altered states of consciousness.