The effects of semantic and physical mismatches on auditory event-related potentials in adolescents

The purpose of this research was to examine the effects of semantic and physical mismatches on auditory Event Related Potentials (ERPs). There were ten subjects aged 11 through 15. Five of the subjects were male and five were female. ERPs were recorded as 80 different 4 word sentences were auditorily presented. The sentences either ended normally or were completed by unexpected words that were either a semantic mismatch or loud in volume or both.;Deviances in congruence yielded an early central parietal negative wave around 220 ms. This wave was analogous in its topography and onset to the N400. The short duration of this wave was attributed to the unique auditory paradigm used. The paradigm presented a simple listening task that was conducive to both phonemic and semantic priming. It was postulated that this priming shortened the time needed to perform the language processing tasks; therefore, shortening the duration of the waveform.;It was anticipated that the physical deviation of loudness would produce a P300. This was not observed. Instead a frontal central negative deviation around 200 ms was seen. It was proposed that this wave was the mismatched negativity (MMN) because of its topography, duration and latency.;Results of this study offer research implications for further study. In order to truly investigate the N400's role language processing, several areas must be more thoroughly examined: N400 in children, the N400 in response to an auditory stimulus, and the latency, duration and onset of the N400.