@article{oai:cur-ren.repo.nii.ac.jp:00000188,
 author = {Ogino, Tatsuya and Hanafusa, Kaoru and Morooka, Teruko and Takeuchi, Akihito and Oka, Makio and Tsushima, Yasuko and Sanada, Satoshi and Ohtsuka, Yoko and Ogino, Tatsuya and Hanafusa, Kaoru and Morooka, Teruko and Takeuchi, Akihito and Oka, Makio and Tsushima, Yasuko and Sanada, Satoshi and Ohtsuka, Yoko},
 journal = {Chugokugakuen journal},
 month = {},
 note = {Background: The relationship between reading ability and categorical judgment of speech sounds in children whose native language is Japanese is unclear. The purpose of this study is to elucidate the impact of categorical perception on the development of reading ability in children whose native language is Japanese.
Methods: First, forty second-graders (F18, M22; 7y4m−8y4m) attending a public elementary school were tested for reading time and reading errors using the monomoraic syllable reading test, the word and non-word reading tests, and the single sentence reading test. Reading time scores and reading error scores which lay more than 1.5 times the interquartile range (IQR) higher than the third quartile were considered outliers. Next, 30 out of these 40 children were tested using the categorical perception task. A thirteen-step stimulus continuum from /ka/ to /ga/, made by changing voice onset time, was presented to the subjects with the steps in random order, and the subjects made judgments as to whether each stimulus sounded more like /ka/ or /ga/.
Results: Reading time as assessed through all 4 tasks and reading errors as assessed through the non-word reading test and the single sentence reading test correlated weakly with the Categorical Perception Index (CPI), which indicated the stability of categorical judgment. In addition, the number of scores which were outliers also showed a weak correlation with CPI.
Conclusion: These results suggest that categorical perception ability affects the development of reading ability in children whose native language is Japanese.},
 pages = {39--45},
 title = {Categorical Perception and Reading Skill: A Survey of Japanese Second Graders},
 volume = {13},
 year = {2014}
}