An ERP study on the time course of phonological and semantic activation in Chinese word recognition

With the event-related potential (ERP) technique, we examined the time course of phonological and semantic activation in Chinese word recognition. Participants did a semantic judgment task and a homophone judgment task over the same set of word pairs. Each pair was of either high or low word frequency and the two words were either unrelated or related semantically or phonologically, i.e., being homophones. For high-frequency words, both the semantically related pairs in the homophone task and the homophonic pairs in the semantic task elicited ERP responses different from the unrelated control pairs in the N400 component but not any component earlier, suggesting a similar time course for semantic and phonological activation. For low-frequency words, the semantically related pairs in the homophone task were associated with a similar modulation of N400. However, compared to the unrelated controls, the homophonic pairs in the semantic task elicited a larger P200, a component implicated in phonological processing in the literature, and thus demonstrated a phonological activation earlier than semantic activation. The results showed that word frequency affects the time course of semantic and phonological activation suggesting that phonology is not invariably activated before semantics in Chinese word recognition.