Is it Worth the Hit? Examining the Cognitive Effects of Subconcussive Impacts in Sport Using Event-related Potentials

Abstract

Concussion is a life-altering injury that can affect people of all ages. Event-related potentials (ERPs) extracted from electroencephalography (EEG) have proven sensitive to concussion-induced cognitive deficits. The MMN, P3a, P3b, and N2b are some ERP components of interest, assessing automatic attention, attentional resource allocation, working memory, and inhibitory executive function, respectively. These ERPs can assess some common symptoms associated with concussion at a level that cannot be attained using self-report. A reduced amplitude and potentially delayed latency of the P3a and P3b is a well-replicated result in concussion research. Furthermore, recent research suggests that an alteration in amplitude of earlier peaks such as the N2b and MMN might represent an irreversible change in cognitive processing that tends to occur in the chronic stages of concussion. Many of these studies have focused on athletes, however little research has evaluated the cognitive effects of sustaining numerous blows to the head that do not result in a clinical diagnosis of concussion, as is the case for many athletes in contact sports. These blows are often referred to as subconcussive impacts. The present study examined the cognitive and neurophysiological effects of subconcussive impacts on collegiate contact-sport athletes and compared them to noncontact athletes. The athletes completed questionnaires to evaluate their health and athletic history, as well as estimates of exposure to subconcussive impacts such as position and playing time, prior to participating in three paradigms meant to assess various cognitive processes during an EEG recording. Across two experiments we demonstrated that subconcussive impacts within a season of play can result in alterations in neurophysiological markers of cognitive health. Our findings also reveal that continued involvement in contact sports can have serious implications in one’s automatic attention, resource allocation, and working memory as demonstrated by reduced ERP amplitudes in contact as compared to non-contact athletes.