Handedness and right-left discrimination.

Abstract

Hand preference in manual activity has long been a topic of investigative interest because of its association with the language functions and the concept of cerebral dominance. Similarly, the ability to discriminate between the right and left sides of one's body has claimed attention, although to a lesser degree than is the case with handedness. Psychologists have utilized measures of discrimination as an index of general intelligence and in the genetic study of children's conceptions of space. Neurologists have been particularly interested in the ability ever since the demonstrations by Bonhoeffer (4) and Gerstmann (6) that impairment in discrimination is not only related to the presence of cerebral disease but also may possess localizing significance. While disorientation in pure form (i.e., unaccompanied by more profound disturbances in the body schema) is rather uncommonly encountered in adult patients with cerebral disease, recent investigative work (i) suggests that it may occur in a clinically significant proportion of brain-injured and defective children. The question arises as to whether there is a relationship between these two aspects of laterality or right-left behavior, the motor aspect being represented by degree of hand preference and the perceptual aspect