N2b Reflects the Cognitive Changes in Executive Functioning After Concussion: A Scoping Review

Abstract

Objectives: The N2b is an event-related potential (ERP) component thought to index higher-order executive function. While the impact of concussion on executive functioning is frequently discussed in the literature, limited research has been done on the role of N2b in evaluating executive functioning in patients with concussion. The aims of this review are to consolidate an understanding of the cognitive functions reflected by the N2b and to account for discrepancies in literature findings regarding the N2b and concussion.Methods: A scoping review was conducted on studies that used the N2b to measure cognitive functioning in healthy control populations, as well as in people with concussions.Results: Sixty-six articles that met inclusion criteria demonstrated that the N2b effectively represents stimulus-response conflict management, response selection, and response inhibition. However, the 19 included articles investigating head injury (using terms such as concussion, mild head injury, and mild traumatic brain injury) found widely varied results: some studies found the amplitude of the N2b to be increased in the concussion group, while others found it to be decreased or unchanged.Conclusion: Based on the available evidence, differences in the amplitude of the N2b have been linked to response selection, conflict, and inhibition deficits in concussion. However, due to large variations in methodology across studies, findings about the directionality of this effect remain inconclusive. The results of this review suggest that future research should be conducted with greater standardization and consistency.

Long-Term Cognitive Impairments of Sports Concussions in College-Aged Athletes: A Meta-Analysis

“…The ImPACT Impulse Control composite score could also distinguish between HOC athletes and controls, with HOC athletes performing worse. These results are consistent with neuroimaging and electrophysiology studies of mTBI and SRC using experimental tasks of response inhibition, such as the Flanker, Stop Signal, and Go/No-Go tasks (51–58). However, two studies using the ImPACT battery to investigate the consequences of SRC beyond the acute phase of injury have not found a difference on the ImPACT Impulse Control (59,60).…”

Amplitude-Time Characteristics of Women’s Brain Activity Associated With the Motor Response in the Stop-Signal Task Paradigm

“…Such topography is obviously due to the fact that the parietal cortex areas participate in the processes of sensory-motor integration [21] and the internal representations update based on new sensory information to initiate [22] or suppress actions [23]. It should be noted that some authors more often associate N2 with the occurrence of conflicts in information processing, such as a conflict of response or deviation from the expected results of actions [11,24]. Therefore, increasing the latency of such a component may indicate the occurrence of conflict during the processing of sensory information or even the development of inhibition of initiating subsequent actions [11].…”

Neurophysiological Markers to Guide Return to Sport After Sport-Related Concussion

“…44,45 Unlike P3, which shows some consistency (i.e., decrease), N2b was found to be increased, decreased, or unchanged in the concussion group. 46 This inconsistency with N2b may be because of cognitive demand differences between task (e.g., flanker calls on inhibition). These event-related potential components are used to investigate effects of concussion on cognitive function in research (for review see Krokhine et al 46 ) and are not yet portrayed as clinically useful.…”