Executive functions and intraindividual variability following concussion.

ABSTRACT

UNLABELLED The long-term outcomes of executive functions and intraindividual variability (IIV; i.e., trial-to-trial or across-task variability in cognitive performance) following concussion are unclear due to inconsistent and limited research findings, respectively. OBJECTIVE: Responding to these gaps in scientific understanding, the current study aimed to assess the utility of both executive functions and IIV at predicting concussion history. METHOD: Altogether 138 self-identified athletes (Mage = 19.9 ± 1.91 years, 60.8% female, 19.6% with one concussion, 18.1% with two or more concussions) completed three executive-related cognitive tasks (i.e., n-back, go/no-go, global-local). Ordinal logistic regression analyses examined the joint effect of person-mean and IIV as predictors of concussion status. RESULTS: Only mean response time for the global-local task predicted the number of past concussions, while no IIV variables reached unique significance. CONCLUSIONS: IIV research on concussion remains limited; however, the preliminary results do not indicate any additional value of IIV indices above mean performances at predicting past concussion. For executive functions, shifting appears most sensitive at detecting concussion group differences, with past researchers identifying post concussion impairment in attentional processing.