A re-evaluation of the multi-standard control condition for the existence of a genuine MMN

May, Patrick (2017) A re-evaluation of the multi-standard control condition for the existence of a genuine MMN. Psychophysiology, 54 (Suppl.). S9. ISSN 0048-5772

Abstract

The continuing debate on the genesis of MMN centers on the question of whether MMN reflects differential adaptation of the circuits responding to the standard and deviant (the adaptation hypothesis) or whether it is generated by dedicated deviance detection mechanisms relying on sensory memory (the memory hypothesis). That is, either the MMN expresses response modulation, or it has a separate,specialized generator system which produces a “genuine” MMN. Previous research has attempted to settle this question non-invasively, in favor of the memory hypothesis, through so called multi-standard (MS) control experiments. The current study re-examines these issues in the context of a computational model which is based on the anatomical structure of auditory cortex and includes short-term depression (adaptation) of excitatory connections. In simulations, the model replicates the responses elicited in the oddball and MS conditions without the presence of separate deviance-detection subsystems. Instead, the cortical columns of the model index stimulus-specific adaptation and respond to tone sequences in a highly selective way. These results show that it is doubtful whether MS control experiments can offer reliable non-invasive evidence for the memory hypothesis. Instead, the model supports the adaptation hypothesis, offering a parsimonious account of MMN as part of an adaptation-modulated N1 response. Novel predictions for single and multiunit measurements which could falsify the adaptation hypothesis are offered.