A Comparison of the mismatch negativity and a differential waveform response

Abstract

A mismatch negativity response (MMN) and a new differential waveform were derived in an effort to evaluate a neural refractory or recovery effect in adult listeners. The MMN was elicited using oddball test runs in which the standard and deviant stimuli differed in frequency. To derive the differential waveform, the same standard and deviant stimuli were presented alone. MMN responses were obtained by subtracting the averaged responses to standards from the deviants. The differential waveforms were obtained by subtracting the averaged responses to standards presented alone from deviants presented alone. Scalp topography for the MMN and differential waveforms were similar. A significant (p<.05) positive and negative correlation was found between the earlier and later components of the bimodal MMN and the N1 and P2 component of the differential waveform, respectively. Further, N1 and P2 of the differential waveform were significant (p<.05) predictor variables of early and late peak amplitudes of the MMN. These results suggest that refractory effects may overlay/modify the morphology of the MMN waveform.

Sumario

Se obtuvo una respuesta de negatividad desigual (MMN) y una nueva onda “diferencial” en un esfuerzo por evaluar un efecto neural refractario o de recuperación en sujetos adultos. La MMN fue generada utilizando cursos peculiares de prueba en los que el estimulo estándar y el alterado tenían frecuencias diferentes. Para derivar la onda diferencial, se presentaron el mismo estímulo estándar y el alterado en forma aislada. Las respuestas MMN se obtuvieron restando las respuestas promediadas estándar de las alteradas. Las formas de onda diferenciales se obtuvieron restando las respuestas promediadas a estímulos estándar presentados aisladamente, de los estímulos alterados presentados también en forma aislada. La topografía craneana de los MMN y las onda diferenciales fueron similares. Se encontraron correlaciones positivas y negativas significativas (p<.05) entre los componentes tempranos y tardíos de la MMN bi-modal y de los componentes N1 y P2 de la onda diferencial, respectivamente. Más aún, los componentes N1 y P2 de la onda diferencial fueron variables de predicción significativas (p<.05) de los picos tempranos y tardíos de amplitud de las MMN. Estos resultados sugieren que los efectos refractarios pueden cubrir/modificar la morfología de las onda de la MMN.

• Auditory event-related potentials
• Mismatch negativity
• Neural recovery

Notes

¹We chose to evaluate waveforms recorded from C_Z for two reasons. First our previous work focused on response recorded from C_Z (Walker et al 2001; Cranford et al 2003). Second, it has been suggested that attentional processes influence the topographical distribution of the MMN (Woldorff et al 1991; Näätänen et al 1993). Further, the N2b process that is activated with attention is more strongly represented in the central electrodes (C_Z) rather than the frontal electrodes (F_Z).

²Data from one participant's was lost for these analyses of N1 and P2 ERPs.