Interpreting a Case of Japanese Phonological Alexia: The Key is in Phonology

Abstract

A Japanese patient displayed a striking phonological alexia after a lefthemisphere CVA: KT's accuracy in reading real kanji or kana words was essentially normal; but asked to read simple 2-3-character kana strings with orthographically and phonologically unfamiliar form (nonwords), on which normal Japanese readers easily score 100%, he consistently failed to produce a single correct response. The introduction of phonological familiarity (i.e. creating nonwords homophonic with real words) produced a dramatic facilitation of KT's nonword reading, and this marked “;pseudohomophone” effect furthermore interacted with both frequency and concreteness of the words whose pronunciations were mimicked in the nonwords. KT also showed prominent deficits and lexicality effects in phonological tasks such as segmentation and blending that involve no orthographic processing. His pattern of language and reading performance is interpreted as a deficit in which pathologically reduced activation of phonological representations has differential consequences for word and nonword production.