The effects of physical and semantic incongruities on auditory event-related potentials.

Twenty subjects listened to a series of simple sentences, spoken by a male voice, in which the last word was on occasions either made semantically incongruous or was unexpectedly spoken by a female voice. Averages of ERPs to the last words revealed that a consistent late negative component (N456) was associated with semantic incongruity and a late positive component (P416) with physical (voice) incongruity. The results were consistent with those in the visual modality by Kutas and Hillyard (1980a,b) and are interpreted in terms of the facilitatory and inhibitory effects of contextual priming on the processing of the words concerned. In a subsidiary experiment 6 subjects were required to repeat the last words of the same set of sentences as rapidly as possible. Verbal response latency increased by 62 msec to physically incongruous words and by 185 msec to semantically incongruous words.