Electrophysiological Evidence of Sublexical Phonological Access During Character Naming by Chinese-Speaking Children.

Abstract

The significance of phonological processing skills in learning to read an alphabetic orthography have long been recognized, and deficits in phonological skills have been identified as a core underlying reason for poor decoding in English and other alphabetic scripts. Yet in the case of Chinese, a less transparent script where grapheme-phoneme correspondence rules are not applicable, whether sublexical decoding skills are crucial still remains a controversial issue. Using event-related potential (ERP) technique, this study examined whether typically developing children are sensitive to sublexical phonological access during character naming. Primary grade four children were administered a standardized reading sub-test from the Hong Kong Test of Specific Learning Difficulties of Reading and Writing (Ho, Chan, Tsang & Lee, 2000), and asked to name a character presented on the screen after a cue was shown in a delayed naming task. Characters varied in regularity (regular vs. irregular) and phonological token consistency (consistent vs. inconsistent) factorially. Significant regularity effects were found showing that children named regular characters more accurately than irregular characters. ERP findings showed that regular characters elicited a smaller P200 amplitude in the frontal-central regions, but a larger N400 in the central left hemisphere compared to irregular characters. Significant correlations between reading ability with regularity effect at the N400 were also found, indicating that larger differences in regularity were associated with higher reading ability. Main effects of consistency were only found at the N400 with characters with inconsistent phonetic radicals eliciting a greater negativity than consistent ones. Overall, the findings suggest that the P200 and N400 components are sensitive to sublexical phonological access in Chinese, as more effortful phonological access was required for irregular characters at the P200, and greater lexical semantic competition was needed for retrieving characters with radicals that map onto multiple pronunciations or regular characters whose phonetic radical shared a similar pronunciation with the character. Critically, the findings suggest that sensitivity to sublexical phonological regularity is associated with reading skill.