[Effects of learning experiences on the shift of hemispheric functional asymmetry]

Effects of learning experiences on the direction of shifts occurred in the functional asymmetry of the hemispheres were examined with unfamiliar stimuli. Hangul scripts were presented to 32 right handed university students who had no previous knowledge about Hangul. In the test session 1, the subjects were asked to discriminate the Hangul scripts tachistoscopically presented as fast and accurately as possible, and the left visual field advantage was obtained. The subjects were then assigned into following four groups with different conditions; to teach nothing, to teach the pronunciations of scripts, to teach the meanings of scripts, to teach both the pronunciations and the meanings of scripts. Then, the same discrimination task as that of the test session 1 was repeatedly given as the test session 2. No visual field differences was shown in the pronunciation teaching group, while the left visual field advantage was shown in other three groups. Possible mechanism as for the effects of learning experiences in relation to the hemispheric specialization were discussed.