Electrophysiological estimates of the time course of tonal and orthographic encoding in Chinese speech production

Recent electrophysiological studies have investigated the time course of semantic, syntactic, and phonological encoding in European language spoken production, such as English or Dutch. The present study investigated the time course of tonal and orthographic encoding during Chinese word production. Participants were shown pictures and carried out a dual-choice Go/noGo decision based on tonal information (whether a picture name was tone 1 or 2, or tone 3 or 4) or orthographic information (whether or not the picture name was written with a left-right structure character). Analyses of N200 effects and LRPs (lateralized readiness potentials) indicated that tonal information was retrieved prior to orthographic information. These results imply that orthographic codes are unlikely to contribute to phonological encoding in spoken word production. Furthermore, a late effect for the N200 in the Go/noGo=tone condition was observed, which may be related to internal self-monitoring of suprasegmental information.