[Reading and writing Japanese: Kanji versus Kana]

In my talk, I reviewed studies on the neural substrates of Kanji vs. Kana, two types of Japanese characters, written since the 1980s. More Specifically, I reviewed the development of the studies on (1) Kanji and Kana in pure alexia/agraphia, (2) alexia with agraphia of Kanji and (3) 'musical letters' vs. 'literary letters', and reported new findings from those studies. In the 1980s, we frequently studied patients with partial callosal lesions and those with pure alexia, and many of the studies were on the neural substrates of Kanji vs. Kana. Later, we discovered cases of alexia with agraphia of Kanji caused by lesions in the posterior part of the left inferior temporal gyrus, leading us to understand the neural substrates of Kanji and Kana in more detail. In addition to the reading and writing of 'literary letters', we studied the neural mechanisms of the reading and writing of 'musical letters', i.e. musical scores. Our study showed that the neural mechanisms of reading and writing musical scores were similar to those of reading and writing 'literary letters' in professional musicians, although those neural mechanisms varied slightly.