Perceived language competence modulates criteria for speech error processing: evidence from event-related potentials

With event-related potentials we examined how speaker identity affects the processing of speech errors. In two experiments with probe verification and sentence correctness judgement tasks, respectively, grammatical agreement violations and slips of the tongue were embedded in German sentences spoken in native or Chinese accent. Portraits of European or Asian persons served as cues for speaker's identity. In Experiment 1, only a P600 was elicited by grammatical agreement errors in native speech in the second presentations. In Experiment 2, grammatical errors again elicited a P600 only in native speech. Slips of the tongue, however, elicited a P600 in both native and non-native speech and a N400 for native speech. Hence, perceived speaker nativeness seems to modulate the integration of grammatical agreement violations into the utterance. Slips of the tongue induced (re)interpretation processes (P600) for both native and non-native speech, whereas retrieval of lexico-semantic information (N400) is reduced in non-native speech.