Evaluation of new MMN parameters in schizophrenia.

ERPs could be helpful in the objectification of many psychological measures. In the last few decades one of the most commonly used ERPs has been the mismatch negativity (MMN) potential. It may be used to detect cognitive dysfunction in patients suffering from schizophrenia, dementia, depression, and can also be successfully applied in treatment monitoring. Nevertheless, changes of MMN parameters (prolongation of latency or reduction of amplitude) are not sufficiently specific to help to diagnose particular diseases. In this study we looked for more strict and specific MMN characteristics selective for schizophrenia. Fifteen healthy human subjects and twelve suffering from schizophrenia spectrum disorders were studied. Two new parameters were considered: the speed of ascending part of MMN slope (SAS) and the half area of the MMN wave. These two measures could differentiate the early stages of cognitive processing disturbances in schizophrenia spectrum disorders.