Does effort suppress cognition after traumatic brain injury? A re-examination of the evidence for the Word Memory Test

Abstract

Green, Rohling, Lees-Haley, and Allen (2001) suggested that scores on a test of "effort," the Word Memory Test (WMT), explains more variance in outcome after brain injury than does injury severity. As a consequence, Green and colleagues recommend using the WMT to control for sub-optimal effort in neuropsychological evaluations and group research. We re-examine the evidence for their conclusions and argue that identifying a larger proportion of explained variance is not in itself evidence of validity unless the premise to be proven is already assumed, namely, that the test is a valid measure of effort. Instead, the crux of Green and colleagues claim for the validity of the WMT implies an inte..