51. Neural responses to human voice and hemisphere dominance for lexical-semantic processing--an fMRI study.
- Author
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Koeda, M., Takahashi, H., Yahata, N., Matsuura, M., Asai, K., Okubo, Y., and Tanaka, H.
- Subjects
HANDEDNESS ,LATERAL dominance ,CEREBRAL dominance ,SENSORY perception ,VOLUNTEERS ,VOLUNTEER service ,COGNITION ,HUMAN voice ,PSYCHOPHYSIOLOGY - Abstract
Objectives: In our previous functional magnetic resonance imaging (fMRI) study, we determined that there was distinct left hemispheric dominance for lexical-semantic processing without the influence of human voice perception in right-handed healthy subjects. However, the degree of right-handedness in the right-handed subjects ranged from 52 to 100 according to the Edinburgh Handedness Inventory (EHI) score. In the present study, we aimed to clarify the correlation between the degree of right-handedness and language dominance in the fronto-temporo-parietal cortices by examining cerebral activation for lexical-semantic processing.Methods: Twenty-seven normal right-handed healthy subjects were scanned by fMRI while listening to sentences (SEN), reverse sentences (rSEN), and identifiable non-vocal sounds (SND). Fronto-temporo-parietal activation was observed in the left hemisphere under the SEN - rSEN contrast, which included lexical-semantic processing without the influence of human voice perception. Laterality Index was calculated as LI = (L - R)/(L + R) x 100, L: left, R: right.Results: Laterality Index in the fronto-temporo-parietal cortices did not correlate with the degree of right-handedness in EHI score.Conclusions: The present study indicated that the degree of right-handedness from 52 to 100 in EHI score had no effect on the degree of left hemispheric dominance for lexical-semantic processing in right-handed healthy subjects. [ABSTRACT FROM AUTHOR]- Published
- 2007
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