Ami Sambai

An investigation into kana reading development in normal and dyslexic Japanese children using length and lexicality effects

This is the first study to report differences between Japanese children with and without dyslexia in the way string-length and lexicality effects are manifested when reading Japanese kana. These children were asked to read kana words and non-words consisting of either two or five kana characters. The results showed that the error rates of the normal Preschoolers and Primary-School children with dyslexia were higher than those of the normal Primary-School children. Further, the reading latencies of the normal Preschoolers, First-graders and dyslexics were significantly longer than those of the normal Second, Third and Fifth/Sixth graders. Moreover, reading latencies became shorter as the age of the participants increased. Both normal and dyslexic children showed significant effects of length and lexicality on reading latencies. However, the interaction between the length and lexicality was only seen in normal children from the Second-grade onwards. These results suggest that (1) normal First-graders reach a ceiling in terms of reading accuracy and that (2) as Japanese normal children become older, they become better at lexical reading processes, which leads to fluent kana reading, but that (3) the dyslexics, even at Fifth/Sixth grades, have not developed sufficient lexical reading processes.

The effect of the position of atypical character-to-sound correspondences on reading kanji words aloud: Evidence for a sublexical serially operating kanji reading process

In English, the size of the regularity effect on word reading-aloud latency decreases across position of irregularity. This has been explained by a sublexical serially operating reading mechanism. It is unclear whether sublexical serial processing occurs in reading two-character kanji words aloud. To investigate this issue, we studied how the position of atypical character-to-sound correspondences influenced reading performance. When participants read inconsistent-atypical words aloud mixed randomly with nonwords, reading latencies of words with an inconsistent-atypical correspondence in the initial position were significantly longer than words with an inconsistent-atypical correspondence in the second position. The significant difference of reading latencies for inconsistent-atypical words disappeared when inconsistent-atypical words were presented without nonwords. Moreover, reading latencies for words with an inconsistent-atypical correspondence in the first position were shorter than for words with a typical correspondence in the first position. This typicality effect was absent when the atypicality was in the second position. These position-of-atypicality effects suggest that sublexical processing of kanji occurs serially and that the phonology of two-character kanji words is generated from both a lexical parallel process and a sublexical serial process.