Functional Specialization of Semantic Processing to Chinese Characters: Developmental Studies
Date Issued
2015
Date
2015
Author(s)
Lee, Shu-Hui
Abstract
Reading development is associated with maturational changes in the brain. However, the neural mechanisms of reading development are not fully understood. This thesis used behavioral measures and functional magnetic resonance imaging (fMRI) to investigate developmental changes in orthographic, phonological, and semantic representations for reading Chinese characters. Experiment 1 used a longitudinal fMRI approach to explore the neural substrates of semantic processing to written Chinese characters in the lexical level. The results demonstrated that processing weak association pairs produced greater activation in posterior middle temporal gyrus, reflecting a greater developmental increase between time 1 and time 2 for the children as compared to that for the adolescents. The developmental increase indicates greater improvements of accessing semantic representations via enhanced interconnections for weaker association pairs. Experiment 2 used a cross-sectional fMRI study with two visual tasks (visually-similar task vs. visually-dissimilar task) to investigate the interaction of semantic and orthography in both the lexical and sublexical levels. The results showed a greater developmental increase in left angular gyrus (BA 39) activation in the visually-similar compared to the visually-dissimilar task for strong association pairs. The results suggest that shared semantics at the sublexical level facilitates the integration of overlapping features at the lexical level in older children. Experiment 3 used a behavioral study with a cross-modal paradigm to demonstrate the relationship among semantic, orthography, and phonology in both the lexical and sublexical levels. Children performed better on accuracy for high relative to low transparency in the strong association. Moreover, the results showed a reduced difference in accuracy for high than for low transparency for time 2, compared to that of time 1. These findings demonstrate developmental changes from a focus on radical components (i.e., sublexical processing) to a focus on whole characters (i.e., lexical processing). The findings in this thesis will advance our understanding of the functional architecture of word recognition systems in children.
Subjects
development
fMRI
semantics
orthography
phonology
Type
thesis
File(s)![Thumbnail Image]()
Loading...
Name
ntu-104-D98227103-1.pdf
Size
23.54 KB
Format
Adobe PDF
Checksum
(MD5):2f68fca5bf8961a589bcb5eaa53825cd