Brain potentials during semantic and prosodic processing in French.

The present experiment was aimed at investigating the on-line processing of semantic and prosodic information. We recorded the Event-Related brain Potentials (ERPs) to semantically and/or prosodically congruous and incongruous sentences that were presented aurally, to study the time course of semantic and prosodic processing, and to determine whether these two processes are independent or interactive. The prosodic mismatch was produced by cross-splicing the beginning of statements with the end of questions, and vice-versa. Subjects had to decide whether the sentences were semantically or prosodically congruous in two different attention conditions. Results showed that a right centro-parietal negative component (N400) was associated with semantic mismatch, and a left temporo-parietal positive component (P800) was associated with prosodic mismatch. Thus, these two electrophysiological markers of semantic and prosodic processing differed in their polarity, latency and scalp distribution. These differences may indicate that the two processes stem from different underlying generators. However, the finding that the P800 elicited by prosodic mismatch was larger when the sentences were semantically incongruous than congruous suggests that the two processes may be interactive.