Visual and cognitive perspective-taking impairments in schizophrenia: A failure of allocentric simulation?

Introduction. Poor mentalising in some patients with schizophrenia has been attributed to disruption of a cognitive module dedicated to computing meta-representations (representations of beliefs about propositions) and linked specifically to paranoia. Because meta-representational capacity is needed to infer beliefs but is not needed to judge visual perspectives (which can be done by mentally rotating primary representations of seen objects), this view predicts that patients with selective mentalising deficits will show intact visual perspective-taking. Method. This study tested that prediction by investigating visual perspective-taking in patients and healthy controls, known to differ in mentalising ability. Item questions (asking locations of array-features) and appearance questions (asking how an array appears from another perspective) were presented with both viewer-rotation instructions (asking subjects to imagine moving themselves relative to an array) and array-rotation instructions (asking subjects to imagine rotating an array relative to their fixed viewpoint). Results. Whereas patients performed as well as controls on item questions (regardless of instruction) and appearance questions under array-rotation instructions, patients made more egocentric errors than controls judging appearance questions under viewer-rotation instructions. Conclusions. Our findings count against traditional theory-of-mind accounts and suggest instead that poor mentalising in schizophrenia is better understood as an impairment of perspective-taking.