Computational model for Kanji and Kana reading (1)

Abstract

    We propose that the basic process of kanji and kana reading is captured in a triangle framework suggested by Seidenberg & McClelland (1989), which assumes that the orthography, phonology, and meaning of words are interactively computed on the basis of parallel distributed processing. Our proposal, that the identical architecture and algorithm apply to both kanji and kana strings, found support in normal readers performance : In reading aloud two-character kanji words, normal readers were slower at low-frequency words with atypical character-correspondences than at either high-frequency words or words with consistent/typical correspondences. They could read aloud two-character kanji nonwords fluently. Normal readers were slower at low-imageable words than at high-imageable words, but the imageability effect emerged only when the target was low-familiar kanji words with atypical character-sound correspondences. In reading aloud kana nonwords, normal readers were faster at pseudohomophones (viz. orthographic nonword homophonic with real words) than at non-homophonic nonwords at when the pseudohomophones were homophonic with high-imageable kanji words. These effects indicate that the phonology of kanji and kana strings is computed directly from orthography, with support from meaning when direct computation is inefficient.
    The nature of normal readers' performance suggested that Japanese surface dyslexic patients suffering from semantic impairment should show severe deficit in reading aloud low-familiar kanji words with atypical character-sound correspondences, but relatively preserved performance for high-frequency words or words with typical character-sound correspondences. Furthermore, Japanese phonological dyslexic patients suffering from phonological impairment should be expected to show severe deficit in reading aloud non-homophonic nonwords, but relatively better performance for pseudohomophone homophonic with high-frequency and/or high-imageable words, in whatever script the nonwords comprise. Our assumptions were confirmed by reports of surface and phonological dyslexic patients in the literature and by our own additional tests.