Tzeng, Y. 1 , Hsu, C. 2 & Lee, C. 2
1 Institute of Neuroscience, National Yang-Ming University, Taiwan
2 Institute of Linguistics, Academia Sinica, Taiwan
The present study aims to examine how reading ability shapes children?s brain responses to real characters (RC), pseudo-characters (PS) and non-characters (NC) while performing a pronounceable judgment task. The ensemble empirical mode decomposition method based on the Hilbert-Huang transformation was to extract ERP signals corresponding to N400 (frequency range:1-3Hz). Adult?s data revealed a typical lexicality effect (PS>RC>NC). 53 children from 2nd to 6th grade were subdivided into high-, median- and low- ability groups based on their scores on the Chinese Character Recognition Test (CCRT). Only high-ability group showed an adult-like pattern. A correlation analysis showed significantly positive correlations between CCRT scores and lexicality effects (RC-NC) from 300 to 450 msec in central-posterior sites (ranging from .27 to .46). Children with higher CCRT sores, their brain responses to RC tend to elicit more negative N400 than those to NC did. These findings support that children would gradually acquire the orthographic knowledge as they learned more Chinese characters. Beside, the frequency-based analysis method provides a potential solution to the overlapping component problem in traditional ERP analysis to identify neural markers for reading development.