A Study on the Cerebral Lateralization Index using Intensity of BOLD Signal of functional Magnetic Resonance Imaging

摘要

This study proposes a new cerebral lateraliza-tion index on the basis of neural activation intensity. Eight right-handed male college students (mean age 23.5 years) and ten right-handed male college students (the mean age - 25.1 years) participated in this study of visuospatial and verbal tasks, respectively. Functional brain images were taken from 3T MRI using the single-shot EPI method. A cerebral laterali-zation index based on neural activation area (i.e. number of activated voxels) and another based on neural activation inten-sity (i.e. intensity of BOLD) were calculated for both cognition tasks. The result of calculating a cerebral lateralization index based on neural activation area suggested that the right hemi-sphere is dominant during visuospatial tasks and the left hemi-sphere is dominant during verbal tasks. When a cerebral lat-eralizationn index was computed on the basis of the neural activation intensity, it was shown that the area of cerebral lateralization closely related to visuospatial tasks is the supe-rior parietal lobe, and the area of cerebral lateralization closely related to verbal tasks is the inferior and middle frontal lobes. Since the proposed method can determine the domi-nance of the cerebrum by each area, it can be helpful to de-termine cerebral lateralization accurately and easily.