Speaking words in the second language: From semantics to phonology in 170 ms

The temporal course of semantic and phonological retrieval when producing words in the second language was investigated using ERP technique. In the experiment, less proficient Chinese-English bilinguals were required to name pictures in their second language. Before performing this task, they carried out a dual choice go/nogo task on the basis of a picture's semantic information (i.e., whether the picture was of an object or an animal) and phonological information (e.g., whether the picture's English name starts with the letter C or F). During the time window of 200-600ms after stimulus onset, nogo trials generated a more negative ERP profile relative to go trials. A clear-cut N200 was obtained from their difference waves. Overall, the peak latency of N200 elicited by semantic information is earlier than that by phonological information. It takes unbalanced bilinguals approximate 170ms to retrieve phonological information after semantic information becomes available in the second language production. These findings suggest that the semantic information is encoded earlier than the phonological information during the second language production.