Neural mechanism of reading and writing in the Japanese language.

Three Japanese patients presenting with pure alexia showed agraphia for Kanji in addition. A left angular gyrus lesion caused agraphia for both Kanji and Kana, but Kanji reading was preserved. A left posterior inferior temporal (PIT) lesion resulted in alexia and agraphia for Kanji, while the Kana function was preserved. These results imply that the semantic processing of reading Kanji words depends upon the left PIT area, while the phonological reading of Kana is mediated by the left angular gyrus. The PIT area also plays an important role in writing Kanji words.