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Although the majority of studies on musical processing in musicians observed a left hemisphere dominance which has usually been explained by a proficient analytical strategy used by these subjects, the findings are still inconsistent. Changes in hemispheric activity induced by listening to music (J. S. Bach fugues) and by recognizing the repetitions of the fugue theme were examined, using the technique of bilateral transcranial Doppler sonography (TCD) of the left and right middle cerebral artery (MCA). Subjects were 32 right-handed musicians, half of whom were members of an orchestra or members of a choir. The fugues were presented in two versions: a-cappella and instrumental. During passive listening to the a-cappella version, a weak left-dominant asymmetry of blood flow acceleration was observed, while there was no hemispheric asymmetry during listening to the instrumental version. During the task of fugue theme recognition, a highly significant asymmetry in favour of the right MCA was observed with both versions. It is concluded that when the processing of complex musical material has to be based on the analysis of melodic contour features and calls for working memory capacities a right hemisphere dominance is observed even in musically sophisticated subjects.

Hemisphere specific changes of blood flow velocity in the right and left middle cerebral artery (MCA) induced by cognitive demands of verbal and nonverbal tasks were examined by means of a newly developed technique of simultaneous bilateral transcranial ultrasonic Doppler sonography (TCD). Thirty-one right-handed healthy volunteers served as subjects. Identical stimulus and response procedures were used with all tasks to avoid possible differential effects of these conditions on blood flow velocity. Compared to the preceding resting phase, the increase in flow velocity induced by each of the verbal tasks (sentence completion, similar or contrasting word meaning, similarities) proved to be significantly higher in the left than in the right MCA. Among the non-verbal visuospatial tasks only the "identical pictures" (perceptual speed) task led to a complementary higher increase in right MCA blood flow velocity. No such asymmetry in blood flow acceleration was observed, however, with the tasks "figure assembly" and "cube comparison" which require visualization and mental rotation of figures. The findings underline the recently emerging uncertainty in neuropsychological research with regard to the functional specialization of the right hemisphere.

Two nonverbal tasks (Nebes' Figural Unification Test and Arc-Circle Matching Task) were given to 10 aphasic patients and 10 normal controls. Observations in split-brain patients have shown that the right hemisphere performs almost normally on these tasks while the left hemisphere fails completely. Left and right hand performances of aphasics and controls were compared with those of split-brain patients as reported in the literature. In the Figural Unification Test the aphasics' left hand performance was significantly poorer than that of split-brain patients. This is interpreted as an effect of left hemispheric interference with right hemispheric nonverbal performance. The lack of a similar impairment of left hand performance in the Arc-Circle Matching Task suggests that this interference is only provoked by tasks which, due to the possible verbalization of stimulus material, tend to stimulate left hemispheric activity.

The possibility of hemisphere interaction in the processing of spoken language was studied in two dichotic listening experiments. The stimulus material consisted of six CV syllable triplets each spoken with each one of six intonation contours. In Experiment I, 15 aphasic patients, 8 patients with unilateral right hemisphere lesions, and 10 normal controls were asked to identify the four components of a dichotic item from a multiple-choice (MC) set comprising all possible CV triplets and intonation contours. In Experiment II, 30 normal subjects were required to identify either the right or left ear stimulus alone from an MC set comprising the right and left ear stimulus together with the two wrong combinations of right ear CV triplet with left ear intonation and vice versa. It is concluded from the results that the left hemisphere is capable of processing both phonetic and intonational information and that there is neither the necessity nor the tendency for right hemisphere participation in the perception of spoken language.

This article reports that patients with right temporal lobe damage scored significantly lower in the Recurring-Figures-Test (RFT) than normal controls while patients with left temporal lobe damage were not inferior to the control group in a normatiove study. The RFT was applied using a German translation given in the test manual. The test material consists of 20 stimulus form 7 blocks of 20 trials. Within each block, 8 mixed at random with 12 new figures. The Recurring-Figures-Test is a valid instrument for the assessment of non-verbal memory function.