Reading kanji without semantics: Evidence from a longitudinal study of dementia

要旨

The effects of the degenerative disease process on patterns of oral reading and reading comprehension of Japanese kanji words were investigated longitudinally in 3 demented patients, based on repeated administration of the 50-item Kanji Pronunciation-Comprehension Test (K.P.C.T.) and a battery of tests assessing a variety of cognitive abilities including semantic memory. On the K.P.C.T., all 3 patients showed essentially perfect oral reading until the very advanced stage of the disease process, which was in marked contrast to the progressive deterioration of their ability to comprehend the same set of words. These findings, consistent with some interpretation of lexical nonsemantic reading in English-speaking neurological patients, suggest the existence of an independent orthography-to-phonology transcoding procedure for kanji words. An interesting discrepancy in the pattern of word pronunciation performance, however, was noted between the Japanese patients (co-existence of near normal word naming and progressive deterioration of comprehension) and the Englishspeaking demented patients with analogous “nonsemantic reading” (emergence of regularisation errors in exception words relatively early in the disease process). Possible explanations and hypotheses for this discrepancy are presented.

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