Previous | Next | To the beginning
Conventional lesion studies of alexia/agraphia without aphasia has revealed the important role of the left posterior inferior temporal area (left PIT) in reading and writing Japanese morphograms (kanji), whereas the left angular gyrus (left AG) has been regarded as the cortical center of reading and writing in Western languages. We carried out H215O - PET scan activation studies on normal subjects for analyzing the neural mechanism of reading Japanese. The subjects were reading aloud one of the following letter strings: 2-letter kanji words, 3-letter kana (phonogram) words, or meaningless strings of 3 kana letters (kana non-words). The subtraction images (reading-aloud task - fixation task) of rCBF revealed that bilateral PITs were activated in all three tasks. Lateral occipital areas of both hemispheres were activated in kana-word and kana-non-word reading, while no significant activation in this area was noted during kanji-word reading. Broca'a area and its right side counterpart, the bilateral transverse gyri, and the medial frontal lobe were also activated during all reading tasks. Inferior parietal lobule, especially the AG was not activated at all in any of the used reading tasks. Brain mechanism of reading and writing the Japanese language
Makoto IwataDepartment of Neurology, Tokyo Women's Medical University, Tokyo 162, Japan
We are now investigating the cortical areas responsible for the writing process, using the near infra-red light topography method invented by Koizumi et al. at Hitachi's Central Research Laboratory.
