When Japanese write kana letters, they convert phonemes to kana letters and write them down (e.g., /ka/→か) . When typing kana letters, they romanize the phonemes and type the romanized letters (e.g., /ka/→KA→か) . As kana writing and typing are differently processed as such, the general view is that rehabilitation should be planned specifically for each of these two abilities. However, we experienced a case of chronic aphasia who showed improvement in both writing to dictation of kana letters and typing of aurally presented moras after a newly devised relearning training of phoneme-to-letter conversion.
The patient was a male in his 40s with cerebral hemorrhage in the left temporoparietal lobe. He showed deficits in writing of hiragana and roman letters to dictation, and in typing of aurally presented moras. On the other hand, he showed good performance in transcribing visually presented kana to roman letters and in typing them. He underwent relearning training, in which auditory presentation of a mora was paired with visual presentation of the corresponding kana letter, wherein a line drawing having the corresponding initial sound of its name was simultaneously presented and he copied the letter repeatedly. It was confirmed in another session that he could name those drawings. He showed improved performance in writing hiragana and roman letters to dictation and typing of aurally presented moras. He commented that he recalled the line drawings used in the training when writing and typing the moras. The visual, semantic, and phonological information involved in the training may have facilitated the relearning of phoneme-to-hiragana conversion, and improved the performance in writing hiragana of aurally presented moras. We concluded that the patient regained typing ability of aurally presented moras not with romanization of the moras but with visualization of the corresponding kana letters.
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