The Word Memory Test and the Validity of Neuropsychological Test Scores

Abstract The Word Memory Test (WMT; Green, Allen, & Astner, 1996) contains measures that are very sensitive to exaggeration or poor effort but insensitive to all but the most extreme forms of cognitive impairment. The WMT is unique among symptom validity tests because of its extensive validation in clinical forensic settings, rather than relying on simulation research with healthy volunteers. Effort measured by the WMT predicted 50% of the variance in a total of 30,736 neuropsy-chological test results from 904 consecutive patients involved in com-pensation claims. In group data, WMT-measured effort was sufficient to eliminate or reverse major effects, such as the presence of greater impairment in people with severe versus mild head injuries. The removal of invalid data from people failing the WMT was found to make a major difference to the conclusions of several studies. Properly interpreted, the WMT will meet Daubert challenges.