[Right parietal lesions, spatial neglect and egocentric reference]

Using a proprioceptive "straight-ahead" pointing task, we determined the position of the subjective sagittal middle in thirty unselected patients with unilateral vascular lesions in the right hemisphere and twenty-two normal controls. Patients with extensive right parietal damage (n = 16) showed an ipsilesional (rightward) deviation of their egocentric reference, whereas patients with lesions that substantially spared the right parietal lobe (n = 14) showed a contralesional (leftward) deviation. No significant correlation emerged between the position of the egocentric reference and the performance on a neglect battery. These results can help explain some dissociations between left neglect signs and ipsilesional deviation of the egocentric reference, and raise some questions about the links among lesion location, neglect signs and egocentric frame of reference.