Abnormality of Auditory Mismatch Negativity in Depression and Its Dependence on Stimulus Intensity.

Mismatch negativity (MMN) is thought to reveal several abnormalities of cognitive functioning. Although depression often affects cognitive functioning, previous studies concerning MMN in depressed patients provided conflicting results. In recent reports, it has been suggested that depressed patients may show abnormal auditory response to regular auditory stimuli presented with at a relatively high intensity.