Measurement and interpretation of the mismatch negativity

The mismatch negativity (MMN) is a preattentive brain response elicited by changes in repetitive auditory stimulation. Usually, it is identified as the difference between the event-related potential elicited by a high-probability standard and that elicited by a low-probability deviant stimulus. Most likely, MMN is generated by the outcome of a comparison process that registers a difference between the neural representation of the actual input and the memory trace of the standard stimulation. Since its discovery by Naatanen and colleagues in 1978, MMN has become a useful tool for investigating the brain's auditory information processing in several hundred studies. The present paper describes problems related to the measurement and interpretation of MMN. First, it reviews important features of MMN. Second, it provides technical information about recording and parametrization of this brain wave. Third, it discusses various methodological aspects which may be taken into account in the designing of MMN experiments. Fourth, it addresses some conceptual problems that have to be considered in the proper interpretation of MMN.