Neuromagnetic signals associated with reading a kanji character formed by combining two kanji radicals

To find out which brain regions are responsible for the mental construction and recognition of a kanji character initiated by visually presented kanji radicals, rather than by information retained in the memory, a left hen ra dical and the corresponding right tsukuri radical were simultaneously prese nted randomly to either the left or right visual field of seven subjects. T hirty left hen radicals and the corresponding right tsukuri radicals were p repared as stimuli, this combination formed over 500 real or pseudo kanji c haracters. Instead of their usual left and right positions, the left hen ra dical was always presented above the right tsukuri radical. As quickly and correctly as possible, the subjects released a key when two kanji radicals constituted a single real kanji character and released another key otherwis e. We recorded neuromagnetic responses as well as accuracy and reaction tim e. Left visual field superiority was observed as regards accuracy. This is in good agreement with previous neuropsychological results. Equivalent curr ent dipoles were localized mainly in the left and/or right occipitotemporal regions (ventral visual pathways), the bilateral occipitoparietal regions (dorsal visual pathways) including the supramarginal region, and the areas surrounding the left superior temporal cortex. We suggest that these region s are related to reading and the mental construction of a kanji character f rom its radicals.