Dichotic listening ear preference after childhood cerebral lesions.

Patients with unilateral (right or left) nonprogressive cerebral lesions acquired in infancy (before age one) or childhood (ages one to fifteen) were given a dichotic listening test. The two groups of patients with the childhood lesions showed the pattern of ear preference typically seen after hemispheric lesions in adults; loss of right ear preference after left hemisphere (LH) lesions, and enhanced right ear preference after right hemisphere (RH) lesions. The two groups of patients with the very early lesions failed to show any consistent ear preference or to differ from one another in ear preference. It is postulated that this lack of a consistent lesion effect following very early lateralized brain lesions is due to the greater degree of functional reorganization that takes place after such lesions.