The Stability of the Mismatch Negativity Event-Related Potential in Head Impact Exposure and Concussion

Abstract

Concussive injuries are well documented as having a variety of acute and chronic health effects, and there is increasing evidence for cognitive health effects following repetitive head impact exposure even without the clinical presentation of injury. Event-related potentials (ERPs) recorded from electroencephalography (EEG) are uniquely suited to examine these effects due to their temporal resolution and specificity. ERP research requires a balance between collecting enough data to obtain a reliable response and optimizing the length of the experimental task so as not to be onerous for the participant; however, there is limited research addressing the stability of ERPs with an increasing number of trials. The present study investigated the stability of the mismatch negativity (MMN), an ERP associated with pre-attentive processing, in the context of head impact exposure history. Forty-one athletes with varying histories of head impact exposure and concussion completed EEG recording during a three-deviant auditory oddball paradigm. Data were analyzed with an increasing number of MMN trials using multiple indices of robustness and stability including Pearson’s correlation, Cronbach’s alpha and R2. Results indicated that head impact exposure did not influence the reliability of the MMN. A reliable response was obtained with a minimum of 40 trials for a duration deviant, 50 trials for a frequency deviant, and 60 trials for an intensity deviant. Moreover, over 70% of the variance in total MMN amplitude was uniquely explained by the average of as few as 30 MMN trials in all three deviant types. The study was limited by a small sample size and varying quantifications of head impact exposure. The findings provide preliminary evidence that the MMN can be reliably observed with fewer trials than is currently the norm and can be applied to shorten paradigms and reduce the burden placed on participants.