Executive dysfunction in traumatic brain injury: The effects of injury severity and effort on the Wisconsin Card Sorting Test

Abstract

This study examined the persistent effects of traumatic brain injury (TBI) on Wisconsin Card Sorting Test (WCST) performance. Since poor effort can contaminate results in populations with incentive to perform poorly, performance validity was explicitly assessed and controlled for using multiple well-validated cognitive malingering indicators. Participants were 109 patients with mild TBI and 67 patients with moderate-to-severe TBI seen for neuropsychological evaluation at least one year post injury. Patients with diffuse neurological impairment and healthy controls were included for comparison. Results suggested a dose–response effect of TBI severity on WCST performance in patients providing good effort; the mild TBI group did not differ from controls while increased levels of impairment were observed in the moderate-to-severe TBI group. Effort during testing had a larger impact on WCST performance than mild or moderate-to-severe TBI. Clinical implications of these findings are discussed.

Keywords:

• Traumatic brain injury
• Wisconsin Card Sorting Test
• Executive function
• Outcome
• Performance validity
• Effort
• Malingering

Results from this study were presented at the 36th Annual Meeting of the International Neuropsychological Society. Parts of this study were also submitted as a thesis by the first author to the Department of Psychology of the University of New Orleans in partial fulfillment of the requirements for the degree of Master of Science in Psychology. This project is one component of a much larger data collection project. Our research assistants, including Jeffrey Love, Matthew Heinly, Kelly Curtis, and Adrianne Brennan, have been tireless, and their efforts are much appreciated.