Double dissociation between representational personal and extrapersonal neglect

BACKGROUND: Although perceptual and representational neglect are frequently associated, the demonstration of a double dissociation between both neglect forms suggests that both rely on different central mechanisms. In addition, perceptual neglect can be selectively observed within personal space or extrapersonal space. However, it is not known whether the latter dissociation also exists in representational neglect. METHODS: The authors investigated this question in two brain-damaged patients with anatomically different lesions sites, using neuropsychological tests specifically designed to assess perceptual and representational neglect in both personal and extrapersonal space. RESULTS: Patients presented a double dissociation with respect to personal and extrapersonal space in representational neglect. CONCLUSIONS: These data suggest that the cerebral networks that process mental space representation use similar principles of space compartmentalization as those used by cerebral networks processing perceived space.