Mismatch negativity: A systematic review of the spatiotemporal pattern of adaptation and prediction error in MMN

Since its discovery in the late 1970s, the mismatch negativity (MMN) has sparked a large and still-growing research agenda. The MMN has been assumed to reflect neuronal processes related to the detection of changes in regular sensory input, mainly based on prediction error (PE) generation, i.e., increased responses to unexpected, deviant stimuli. However, alternative models for the PE account, for example, suggest that the MMN is mainly based on adaptation to standard stimuli. This systematic review focuses on studies that aim to reveal the mechanisms that shape the MMN using methodological approaches such as suitable control conditions, dynamic causal modeling (DCM), and neurocomputational modeling. We searched for all suitable studies and tried to identify the spatiotemporal pattern associated with possible different mechanisms of MMN generation. Results of the review indicate that adaptation- and PE-related processes display amplitude maxima at different time points (adaptation occurring earlier, prediction later) within the MMN time window across sensory modalities, experimental variations (such as oddball paradigm, oddball feature, or task conditions), and analytical approaches. Furthermore, based on reviewed source modeling, DCM studies, and additional discussion of suitable brain imaging data, adaptation-related processes are mainly associated with sensory brain regions. In contrast, PE-related processes are found across the sensory pathways, but predominantly observed in hierarchically higher brain areas in the fronto-parietal and temporal cortex. Based on the reviewed studies and theoretical and methodological considerations, we suggest future directions of research in the field.