Test–retest stability of the magnetic mismatch response (MMNm)

Objective We investigated the replicability of the magnetically measured mismatch negativity (MMNm). Methods The MMNm was recorded twice by using a 122-channel whole-head magnetometer in 15 healthy young adults. The MMNm responses for duration, intensity and frequency deviants were analyzed separately in left and right hemispheres for the response strength, latency, dipole moment, and generator loci. Results In the right hemisphere, the test–retest correlations were statistically significant for all MMNm parameters (r=0.49–0.89). In the left hemisphere, the majority of the MMNm parameters also demonstrated statistically significant test–retest correlations (r=0.61–0.82). In addition, the MMNm generator loci were stable for all deviants. Conclusions and significance The present results are encouraging in terms of both research and clinical use of MMNm in studying human auditory discrimination in its normal and deteriorated states.