The mismatch negativity (MMN) is an automatic change-detection response of the brain elicited even in the absence of attention or behavioral task (Naatanen et al., 2012). MMN is typically elicited by auditory stimuli that deviate in some respect, such as frequency, intensity, or duration from the preceding more frequent stimuli and thus reflects the mismatch between the current sensory input and the memory representation of the preceding auditory stimuli. MMN is generated by the process of early change detection in the left and right auditory cortices and subsequent prefrontal activation. We are aware of only one published twin study of MMN (Hall et al., 2006b). In this study, both test-retest reliability and heritability of duration MMN amplitude was high (.66 and 68%, respectively), suggesting that the entire trait-like variance in MMN is genetically determined. However, this study was based on a modestly-sized sample (40 MZ pairs and 30 DZ pairs), therefore these point estimates should be interpreted with some caution. Importantly, a recent case-control study confirmed high test-retest reliability of MMN and has assigned this measure one of the highest
