Perspective taking to assess topographical disorientation: Group study and preliminary normative data.

Difficulty in navigating in a well-known environment (i.e., topographical disorientation) is an incapacitating syndrome. Despite the relatively high frequency after a right cerebral lesion, there is currently a dearth of neuropsychological tests to assess it. We propose a completely new test, the third in a battery of three, which assesses perspective taking, a crucial process in spatial orientation. In this test, inspired from Piaget and Inhelder Three Mountains, the subject must imagine a change in perspective in two conditions: after a rotational or a linear displacement. This task was proposed to 63 patients with a right cerebral lesion and a control group (N = 112). Results show that a right cerebral lesion impairs perspective taking, more specifically when rotation is involved. In addition, the pattern of responses in patients indicates that they have a general deficit in the ability of decentering. Furthermore, we established preliminary normative data taking into account the effect of age and education (there was no effect of gender) on performance. These data indicate that this new test is a good tool in clinical practice for assessing spatial orientation and determining more precisely the symptoms underlying topographical disorientation.