Neuropsychological characteristics of right hemisphere damage: investigation by attention tests, concept formation and change test, and self-evaluation task.

Neuropsychological characteristics of right (non-dominant) hemisphere damage were investigated by attention tests, a concept formation and change test, and a self-evaluation task on a total of 126 brain damaged subjects (66 right hemisphere damaged and 60 left hemisphere damaged). Common response patterns specific to subjects with right hemisphere lesions were studied by three attention tests (audio-motor method, cancellation test, and set dependent activity test). Those with right hemisphere lesions showed a large number of responses (excessive response) and low proportion of correct responses (low hit rate, qualitative deterioration of response), indicating a tendency toward randomness. A concept formation and change test, the new modified Wisconsin Card Sorting Test, was performed to investigate the handling of higher concepts. Only the frequency of difficulty of maintaining set (DMS) was significantly higher in those with right hemisphere lesions. Problems concerning attention and attitude toward the tests, i.e. random attitude were thought to exist in those with right hemisphere damage. Self-evaluation and corrective ability were studied on the self-evaluation task using the audio-motor method. Feedback was less effective in subjects with right hemisphere lesions, and they tended to underestimate their errors. These results were consistent with personality characteristics such as the lack of a serious attitude and poor volition for treatment, which are frequently observed in clinical settings. The above are considered basic, common characteristics of right hemisphere damage. These findings may partially explain the phenomenological characteristics of right hemisphere damage described by various investigators.