Directors: Antonio M. Battro and Kurt W. Fischer
Program officer: María Lourdes Majdalani
Relationships between sensory, cognitive processing skills and literacy development in Japanese
This study aimed to investigate relationships between sensory, cognitive processing skills and the development of literacy skills in Japanese. The Japanese writing system uses phonetic “Kana” and logographic “Kanji” script, both of which differ visually, but share phonological (and often semantic) representations. Forty-three Japanese children in 2nd grade (22 boys and 21 girls, Mean age =7.83 years, SD=3.27 months) were tested in Japan. Thirteen tests consisting of a battery of auditory, phonological, orthographic, visual processing skills and intelligence measures were administered individually. Results suggest that literacy skills in phonetic Kana were best predicted by phonological short-term memory, but NOT by visual short-term memory, while the development of literacy skills in logographic Kanji was explained uniquely by processing skills in all modalities: visual, orthographic, and phonological. This multi-modal involvement in Kanji literacy skills reflects the properties of Kanji script, which is visually complex and needs to be pronounced at the whole-word level due to multiple phonological representations for each Kanji character. It is important to note that the orthographic processing measure that significantly accounted for literacy skills in both Kana and Kanji was most highly associated with dynamic visual sensory processing. It is suggested that the visual magnocellular system could be responsible for dynamic visual sensory processing, which is reported to play an important role in orthographic processing of alphabetic scripts. Thus, the visual magnocellular system may form part of an underlying mechanism supporting literacy skill, irrespective of the writing system or the script. In addition, the present study on the normal development of literacy skills in Japanese may help us to understand the nature of dyslexia in Japanese subjects, which, from the evidence accrued, appears to manifest itself differently from dyslexia in native English speakers.