Right unilateral spatial neglect in aphasic patients.

To investigate spatial responses by aphasic patients during language tasks, 63 aphasics (21 severe, 21 moderate, and 21 mild) were administered two kinds of auditory pointing tasks-word tasks and sentence tasks-in which the spatial conditions of the stimuli were controlled. There were significantly fewer correct responses on the right side of a space than on the left side in both the word and sentence tasks, but the left deviation of correct responses was more prominent in the sentence task than in the word task. Additionally, the severe aphasics exhibited a prominent leftward deviation that may have been the result of deficits in rightward attention controlled by the left hemisphere. This phenomenon also seems to reflect the directional attention that is subserved by the right hemisphere, which attends to the left side of a space and, less predominantly, the right side of a space.

Impaired pitch production and preserved rhythm production in a right brain-damaged patient with amusia.

Pre- and postmorbid singing of a patient with amusia due to a right-hemispheric infarction was analyzed acoustically. This particular patient had a premorbid tape recording of her own singing without accompaniment. Appropriateness of pitch interval and rhythm was evaluated based on ratios of pitch and duration between neighboring notes. The results showed that melodic contours and rhythm were preserved but individual pitch intervals were conspicuously distorted. Our results support a hypothesis that pitch and rhythm are subserved by independent neural subsystems. We concluded that action-related acoustic information for controlling pitch intervals is stored in the right hemisphere.