台大心理系

How does the human brain store and process meanings of words? Emerging evidence has shed light to the cognitive mechanism for adults. However, the functional architecture of word comprehension in children is not fully understood. In a series of experiments, I use a semantic association task (weak vs. strong association) to investigate developmental changes in orthographic, phonological, and semantic representations for reading Chinese characters. In particular, I focus on the issue about how the mapping between lexical representations becomes more automatic with development. Both behavioral and functional magnetic resonance imaging (fMRI) data will be given in this presentation. This talk will provide two sets of developmental studies of meaning processing for Chinese characters. In the first part of the talk, I will discuss the involvement of executive control in semantic processing. Two experiments were used to explore the relationship between phonology and semantics. The findings suggest greater involvement of semantic selection mechanisms in the distantly related pairs (i.e., weak association), particularly in the cross-modal task for processing spoken characters. Moreover, age-related increases in semantic selection were found in the cross-modal task, suggesting a more mature ability in selecting the appropriate meaning over age. In the second part of the talk, I will discuss whether there are visual features in Chinese characters that facilitate semantic judgments. Four experiments were used to explore the relationship between orthography and semantics. The results showed that semantic radicals may help to facilitate the semantic integration process, especially for the closely related pairs (i.e., strong association). In addition, age-related increases in semantic integration were found in processing strong association, reflecting a better ability in integrating contextual relevant information into a coherent concept over age. Overall, these studies aim to provide a cognitive and neural framework of developmental changes for processing meaning.