Normalization of horizontal pseudoneglect following right, but not left, upper limb amputation

Objectives: Subjects who have suffered limb amputations are known to have physiological alterations of their body's representation, or schema. Such changes of brain function might alter the right-left spatial allocation of attention. The goal of this study was to learn if, compared to normal subjects, limb amputees had alterations of right-left spatial attention. Methods: The subjects were veterans with amputation of one upper or lower limb. All subjects performed horizontal line bisections in their left, middle and right body-centered space. Results: Following right upper limb amputation, there appears to be a reduction of the normal left-sided bias (pseudoneglect) primarily for lines presented in the right body hemispace. Conclusions: This amputation-induced alteration of attentional bias might be related to changes in the body schema, a compensatory strategy, or alterations of scanning patterns. Further studies are needed to reproduce these, results and to learn the underlying brain mechanism. Published by Elsevier Ltd.