Executive functions and intraindividual variability following concussion

Justin E. Karr, Mauricio A. Garcia-Barrera, Corson N. Areshenkoff

Research output: Contribution to journalArticlepeer-review

15 Scopus citations


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.

Original languageEnglish
Pages (from-to)15-31
Number of pages17
JournalJournal of Clinical and Experimental Neuropsychology
Issue number1
StatePublished - Jan 2 2014

Bibliographical note

Funding Information:
Justin E. Karr is a Vanier Canada Graduate Scholar and thanks the Natural Sciences and Engineering Research Council of Canada for their support of his graduate studies. This research was supported financially by the American Psychological Foundation/Council of Graduate Departments of Psychology Peter and Malina James & Dr. Louis P. James Legacy Graduate Student Research Scholarship. It was also supported by a University of Victoria Internal Research Grant. The funding sources had no other role than financial support. Address correspondence to: Justin E. Karr, Department of Psychology, P.O. Box 3050, University of Victoria, Victoria, BC, Canada, V8W 3P5 (E-mail: jkarr@uvic.ca).


  • Concussion
  • Executive function
  • Intraindividual variability.
  • Mild traumatic brain injury

ASJC Scopus subject areas

  • Clinical Psychology
  • Neurology
  • Clinical Neurology


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