Abstract
Previous studies have investigated the developmental differences of semantic processing regarding brain activation between adults and children. However, little is known about whether the patterns of structural connectivity and effective connectivity differ between adults and children during semantic processing. Functional magnetic resonance imaging (fMRI), diffusion spectrum imaging (DSI), and dynamic causal modeling (DCM) were used to study the developmental differences of brain activation, structural connectivity, and effective connectivity during semantic judgments. Twenty-six children (8- to 12-year-olds) and 26 adults were asked to indicate if character pairs were related in meaning. Compared to children, adults showed greater activation in the left ventral inferior frontal gyrus (IFG) and left middle temporal gyrus (MTG). Also, adults had significantly greater structural connectivity in the left ventral pathway (inferior frontal occipital fasciculus, IFOF) than children. Moreover, adults showed significantly stronger bottom-up effects from left fusiform gyrus (FG) to ventral IFG than children in the related condition. In conclusion, our findings suggest that age-related increases in brain activation (ventral IFG and MTG), IFOF, and effective connectivity (from FG to ventral IFG) might be associated with the bottom-up influence of orthographic representations on retrieving semantic representations for processing Chinese characters.
Highlights
Previous functional and structural studies have proposed that a dual-stream model for the language network includes the ventral and dorsal pathways that connect the functionally relevant frontal and temporal regions (Saur et al, 2008)
The ventral inferior frontal gyrus (IFG) is associated with controlling semantic retrieval (Lau et al, 2008), while the left middle temporal gyrus (MTG) is considered to be related to the storage of lexical representations (Hickok and Poeppel, 2007; Martin, 2007)
These findings provide converging evidence to understand the developmental differences between adults and children during semantic processing in Chinese
Summary
Previous functional and structural studies have proposed that a dual-stream model for the language network includes the ventral and dorsal pathways that connect the functionally relevant frontal and temporal regions (Saur et al, 2008). Relevance to the structural division, previous studies have suggested functional differences for the sub-parts of the left inferior frontal gyrus (IFG). Regarding developmental differences (ranging from 8 to 20 years) in brain activation, two major brain regions have been suggested to be associated with semantic processing as a network. These two brain regions include: the left ventral IFG and left MTG (Lau et al, 2008). A child study has shown that children have similar activation in the bilateral inferior frontal gyri and left MTG as reported by previous studies of adults for printed words (Chou et al, 2006)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
