This research compares the performance of a sample of non-litigating participants with severe brain injury on both the WMT and TOMM under conditions of (1) full effort, (2) distraction, or (3) simulated malingering. The study included 60 participants with a severe brain injury and used restricted randomization to assign participants to the groups. Following Craik (1982) an auditory distraction task was used during the learning phase of each test in the distraction group, while a scenario adapted from Tombaugh (1997) was used to encourage simulation of memory impairment in the simulated malingering group. The results of this study clearly showed that while both tests demonstrated excellent sensitivity, the false positive rates for the WMT were significantly greater than those for the TOMM. It was concluded that the so-called “effort” components of the WMT required more cognitive capacity than was previously believed. (JINS, 2008, 14, 1074–1080.)