Uchiyama, H. 1, 2, 3 , Seki, A. 1, 2, 3 , Tanaka, D. 1, 2, 3 & Koeda, T. 1, 2, 3
1 Department of Education, Faculty of Regional Sciences, Tottori University, Tottori, Japan
2 Department of Clinical Research, Tottori Medical Center, National Hospital Organization
3 Japan Science and Technology Agency (JST)/Research Institute of Science and Technology for Society (RISTEX), Tokyo, Japan
Studies have shown that the fusiform gyrus (FG), inferior parietal lobes (IPL), and inferior frontal gyrus (IFG) play important roles in the reading of alphabetic languages. Functional MRI (fMRI) studies on alphabetic languages show that the activation of the FG is associated with fluent-word recognition in skilled readers. Although FG has been identified to be crucial for the reading of Japanese logographic kanji characters, but not of phonographic kana characters, it is activated even for kana characters when their visual familiarity is high. This indicates the dynamic changes in reading systems during the development of skills required for reading Japanese. To delineate the age-related changes in the reading system, we conducted an fMRI with 48 school-aged children. Subjects performed a picture-word matching task: they judged whether the given pictures matched the written words and nonwords. The left FG and left IPL were activated more strongly when the students were presented with familiar words than with letter strings (nonwords). This activation in the IPL and left IFG decreased with age, but there was no such decrease in the FG region. This age-related diminishing activation might indicate a change in the reading skill, from letter-by-letter decoding to fluent-word recognition.