以事件誘發電位探討中文假字閱讀中的早期字音提取歷程

The Early Extraction of Sublexical Phonology in Reading Chinese Pseudocharacters: An Event-related Potentials Study

本事件誘發電位 (event-related potentials: ERPs) 研究旨在利用中文假字唸名探討漢字閱讀中讀音提取的歷程。實驗中，受試者會看到一組意旁在左音旁在右所造出的假字。每個假字呈現的同時，也會出現一個語音。這個語音可能是該假字音旁所預期或無法預期的讀音。實驗結果發現，中文假字配對可預期與不可預期之讀音會引發不同的腦電波反應，證實音旁具有提取讀音的作用。而腦電波的差異主要發生在額葉的兩個連續正波，P2a 與P2b，以及N400 的成分上。由於過去的研究指出P2 的成分主要與文字辨識歷程中早期的特徵提取有關，而N400 則反應了詞彙提取後的語意整合歷程。本研究的發現可用以支持漢字閱讀的字音提取可以發生在非常早期的階段。

This event-related potentials (ERPs) study attempts to trace the time course it takes to extract phonology while reading Chinese pseudocharacters. Participants were asked to passively attend to a set of pseudocharacters, each paired with a spoken syllable. This syllable had either a predicable or an unpredictable pronunciation, which was determined by the constituent phonetic radical of the pseudocharacter. The data showed that pseudocharacters paired with predictable or unpredictable pronunciations elicited different ERPs and suggested that Chinese pseudocharacters are pronounceable. Furthermore, pseudocharacters paired with unpredictable pronunciations elicited two greater frontal positivities, p2a and p2b, and an enhanced N400. P2 component could be used to index the early extraction of phonology in reading Chinese pseudocharacter; N400 was associated with the post-lexical processing. These findings suggest that phonetic radicals could be used to suggest pronunciation in the early stage of Chinese lexical processing.