Severity of neglect predicts accuracy of imitation in patients with right hemisphere lesions

Presence and severity of spatial neglect and accuracy of imitation of hand and finger postures were tested in 50 RBD patients. Disturbance of imitation was much more severe for finger than hand postures and was tightly correlated with severity of neglect. The number of errors was higher for fingers which from the patient's perspective were located on the left side of the examiner's demonstrating hand but this spatial bias was not sufficient to explain all errors. Possible causes for non-lateralized errors could be a general narrowing of the focus of attention and reduced capacity for processing of visual information which have been postulated to be regular companions of the lateral displacement of attention in spatial neglect.