# Measuring the Genuine Mismatch Negativity in the Auditory Multi‐Feature Paradigm

## TL;DR

Researchers developed a new method to measure the genuine mismatch negativity (MMN) in auditory processing, revealing that adaptation plays a bigger role than previously thought.

## Contribution

A cascadic control condition was introduced to isolate the genuine MMN from adaptation effects in the multi-feature paradigm.

## Key findings

- Genuine MMN amplitudes for frequency and location were smaller than in traditional paradigms.
- No genuine intensity MMN and only a later, smaller duration MMN were observed.
- Adaptation appears to contribute more strongly to MMN than previously assumed.

## Abstract

The mismatch negativity (MMN) is a well‐studied event‐related potential (ERP) component in the EEG reflecting deviance detection in the auditory modality. It taps into the basic functioning of auditory regularity processing. The auditory multi‐feature paradigm is widely used in sensitive and special populations to measure the MMN simultaneously for different sound features in a short amount of time. It is consensus in the field that both adaptation and genuine deviance detection contribute to the “classic” MMN computed as deviant minus standard ERP difference. However, no attempts have yet been made to disentangle adaptation from the “genuine” MMN in the multi‐feature paradigm. Here, we propose a cascadic control condition for the auditory multi‐feature paradigm that controls for adaptation and physical differences between standard and deviant sounds. Using this new paradigm, we measured the genuine MMN, computed as deviant minus control ERP difference, for frequency, location, intensity, and duration deviants. The genuine MMN amplitudes for frequency and location were found substantially smaller than in traditional paradigms. No genuine intensity MMN and only a later and smaller genuine duration MMN were found. The results suggest stronger contributions of adaptation than in the traditional oddball paradigm. Controlling for adaptation is particularly relevant in research concerning predictive processing and the use of the MMN as a biomarker related to impaired NMDA receptor synaptic transmission as observed in schizophrenia. The presented multi‐feature cascadic control condition enables the measurement of the genuine MMN, which presumably reflects higher‐order cortical computations, such as predictive processing, still in a short amount of time.

We designed and evaluated a cascadic control condition for the auditory multi‐feature oddball paradigm to control for the contribution of physical differences and adaptation to the mismatch negativity (MMN). Smaller, later, or no “genuine” deviant minus control MMNs were found for four sound features compared to “classic” deviant minus standard MMNs. The application of the control condition appears feasible as it allows to separate higher‐order cognitive processes from adaptation in sensitive populations.