Pre-conference workshop: Methodological aspects of MMN research
Tuesday, Sep 8, 2015
MMN Interpretation – the adaptation model
Leibnitz Institute for Neurobiology, Magdeburg, Germany
This presentation serves as a brief introduction to the so-called adaptation model of MMN. This model explains the MMN in terms of physiologically known mechanisms of auditory cortex, namely serial structure, stimulus selectivity, and adaptation realized through short term synaptic plasticity (STP). In its simplest form it suggests that the frequently presented standard stimulus results in stimulus-specific adaptation of auditory cortex. This leads to attenuated responses to the standard and to response recovery when the deviant is presented. The model suggests that the memory system and comparison process underlying MMN generation - as advocated by the orthodox theory of MMN - are physiologically realized by STP and stimulus selectivity, respectively. The adaptation model parts company with orthodox theory by suggesting that the MMN, rather than resulting from a separate change-detection process, is in fact part of a modulated N1 response. The methodological consequence of this is that the subtraction curve technically defining the MMN might actually represent an artefact produced by off-line data analysis.