Poster C86, Wednesday, August 21, 2019, 10:45 am – 12:30 pm, Restaurant Hall
The brain regions involved in development of kana reading skills: a longitudinal f-MRI study of Japanese primary school students
Ayumi Seki1,4, Hitoshi Uchiyama2,4, Tatsuya Koeda3,4;1Faculty of Education, Hokkaido University, 2Faculty of Humanities and Education, The University of Shimane, 3The National Center for Child Health and Development, 4Child Developmental and Learning Research Center, Tottori University
The Japanese phonogram, kana, is highly transparent, and most children acquire the basic decoding skills during their first year of schooling. In the following years, their reading fluency develops greatly. Using a longitudinal fMRI study with children of this period, we investigated the brain activations related to the development of reading fluency. Eighteen Japanese students (12 boys and 6 girls) participated in the functional MRI studies twice at the second grade (G2: aged 8.3±0.3 years) and fourth grade (G4: aged 10.0±0.4 years). The participants performed the picture-word matching task during the scans. Target pictures of familiar objects were presented on a screen along with either visually or auditorily presented words/pseudowords. Twenty stimuli each for six conditions [i.e., matched words(vWM, aWM), non-matched words(vWN,aWN), and pseudowords(vPW, aPW)] were presented in a pseudo-randomized order. In both sessions, reading skills were assessed outside the scanner. The fMRI data were analyzed with SPM8. For the first-level analysis, activation corresponding to each condition was derived with the general linear model. For the second-level analyses, a two-factor repeated-measure ANOVA was conducted to examine the effect of grade (2G/4G) and modality (auditory/visual). To further investigate the task-specific activations, a two-factor ANOVA (grade (2G/4G) × task (WN/PW)) was conducted separately for visual and auditory stimuli. Additionally, the brain activation at G2, which correlated with the reading time at G4, was evaluated with parametric analysis. The activated regions were largely overlapped between G2 and G4. The main effects of grade were found in the bilateral parahippocampal gyrus (G2<G4) and left inferior frontal gyrus (G2>G4). The main effects of modality were noted in the bilateral superior temporal gyrus (aW>vW) and bilateral inferior occipital to the fusiform gyri (vW>aW). The occipital activation was extended more anteriorly at the left side and formed a distinguishable peak at the middle part of the fusiform gyrus (-42, -56, -20), the vicinity of the visual word form area. The ROI analysis showed equivalent activations for three visual stimuli. Greater activations for vWN than vPW were found at the bilateral posterior cingulate cortex, left anterior part of the fusiform gyrus, and the left angular gyrus. The activation of the anterior fusiform (-30, -32, -20) was greater to vWN than to wPW at both G2 and G4, while the other two regions showed the difference mainly at G2. The anterior fusiform gyrus also showed greater activation for aWN than for aPW, suggesting the common semantic processing for both auditory and visual words. The parametric analysis with the reading time of words depicted the left posterior superior temporal sulcus. Stronger activation of this region at G2 was correlated to the longer RT at G4. The results of the present study indicated that the middle part of the fusiform gyrus, VWFA, was involved in reading both words and pseudowords in the transparent kana script. Subsequent reading proficiency was predicted by reduced activation of the posterior temporal area during visual stimuli, implying that localization of brain activation may be the key to the development of reading fluency.
Themes: Reading, Development
Method: Functional Imaging