Abstract:
Objective: To examine the relationship between poor effort, as measured by performance on the Word Memory Test, and baseline performance on ImPACT. Methods: Twenty-five undergraduate volunteers completed the immediate and delayed recall subscales of the WMT, as well as baseline testing on ImPACT. Results: Pearson’s correlations revealed a significant relationship between WMT scores (percent correct) and ImPACT processing speed composite score (r = .58; P = .003). Ten participants who failed the WMT (below 95% correct) had significantly faster ImPACT processing speed composite scores [F(1, 23) = 5.03; P = .035], as compared to 15 participants who completed the WMT at 95–100% correct. One-way ANOVAs revealed no significant between-groups differences on the other four ImPACT composite scores, including Impulse Control. Conclusions: Individuals performing with sub-optimal effort appear to process ImPACT stimuli faster than individuals completing the test with full effort. While this might suggest individuals providing sub-optimal effort are choosing any answer as quickly as possible, this is not reflected by poor performance on the other four composite scores. These results suggest that effort testing should be included in baseline concussion assessment, as decision time/processing speed is compromised by poor effort. In those cases where individuals provide sub-optimal effort, performance on baseline testing should be carefully scrutinized with particular emphasis on accuracy and speed of responses. Further research is required to determine the response patterns of individuals providing sub-optimal effort on specific neuropsychological test measures, especially those measuring response time on a computer.