Motivation and Neuropsychological Performance Following Sports-Related Concussion in College Athletes

Abstract

PURPOSE: The current project examined the impact of differential motivation on baseline versus post-concussion neuropsychological measures in college athletes. METHODS: 360 collegiate athletes were administered a neuropsychological battery prior to and following concussion. High Motivation at Baseline (HMB) and Suspect Motivation at Baseline (SMB) groups were established for each measure based on whether baseline performance fell at least one standard deviation from the mean of the given measure (+1 SD = HMB; −1 SD = SMB). Also, participants were divided into Declined, Stable, and Improved groups according to reliable change indices. Greater improvement on post-injury testing was expected in the SMB group than the HMB group, given hypothesized differences in baseline motivation. Separate repeated measures ANCOVAs (covarying SAT performance and comparing HMB and SMB group performance) were conducted on each of the following measures: Hopkins Verbal Learning Test-Revised (HVLT-R), Symbol Digit Modalities Test (SDMT), Trail Making Test (TMT), Digit Span, Stroop, Controlled Oral Word Association (COWA), and Vigil. Also, the frequency of HMB and SMB participants identified as Declined, Stable, and Improved were compared for each measure utilizing χ2 analysis. RESULTS: SMB groups for the TMT-A (F(1, 28) = 24.73, p < .01), TMT-B (F(1,30) = 4.39, p < .05), Digit Span (F(1,25) = 6.52, p < .01), and Stroop-Color Word trial (Stroop-CW; F(1,28) = 7.55, p < .01) demonstrated greater improvement than the HMB groups. Also, the frequency of Improved participants was greater for the SMB groups on the TMT-A (χ2(1) = 14.30, p < .001), TMT-B (χ2(1) = 7.82, p < .01), Stroop-CW (χ2(1) = 6.00, p = .05), and Vigil (χ2(1) = 8.86, p < .05). CONCLUSIONS: These findings are likely due to lower motivation in the SMB group at baseline for each test. Follow-up analyses suggested that the Stroop-Word trial may be relatively unaffected by fluctuations in motivation. These findings have implications for return-to-play decisions and point to the need for better methods for identification of suspect motivation at baseline. One possible objective method for the identification of suspect motivation will be discussed.