Is autotopoagnosia real? EC says yes. A case study.

We report a case of pure autotopagnosia (AT) following a left subcortical vascular accident. The absence of any language disorder, general mental deterioration or other cognitive impairments in this patient allowed an in-depth study of AT. Several tests of body representation and object and animal representation, as well as tests assessing semantic skills were administered to verify current interpretations of AT. Results showed a clear-cut dissociation between defective performances in body representation tests and normal performances on tests involving other kinds of stimuli. The patient's performances were particularly defective on tests relying on visuo-spatial body representation, but her semantic and linguistic knowledge seemed to be spared. This dissociation between different aspects of body representation supports Sirigu et al.'s hypothesis that multiple, partially independent systems are involved in body knowledge. In agreement with this hypothesis, in the present patient AT seems be due to a deficit in a system that processes the structural properties and relative position of single body parts. The present results, reporting the first observation of a subject not affected by any cognitive impairment other than AT, strongly support the existence of a system specifically devoted to body representation.