Search

Objective: We developed the Shell Game Task (SGT) as a novel Performance Validity Test (PVT). While most PVTs use a forced-choice paradigm with "memory" as the primary domain being assessed, the SGT is a face-valid measure of attention and working memory. We explored the accuracy of the SGT to detect noncredible performance using a simulatordesign study. Participants and Methods: Ninety-four university students were randomly assigned to either best effort (CON) (n=49) or simulating traumatic brain injury (TBI) (SIM) (n=45) conditions. Participants completed a full battery of neuropsychological tests to simulate an actual evaluation, including the Test of Memory Malingering (TOMM) and the SGT. The SGT involves three cups and a red ball shown on the screen. Participants watch as the ball is placed under one of the three cups. Cups are then shuffled. Participants are asked to track the cup that contains the ball and correctly identify its location. We created two difficulty levels (easy vs hard, 20 trials each) by changing the number of times the cups were shuffled. Participants were given feedback (correct vs incorrect) after each trial. At the conclusion of the study, participants were asked about adherence to study directions they were given. Results: Participants with missing data (CON=1; SIM=2) or who reported non-adherence to study directions (CON=2; SIM=1) were removed from analyses. Twenty-five percent in SIM and 0% in CON failed TOMM Trial 2 (<45) suggesting adequate manipulation of groups. Groups were not different in age, gender, ethnicity, or education (all p's>.05). There were 9 participants in each group with concussion/TBI history. TBI history was not significantly related to performance on the SGT in either group, although participants with TBI history tended to do better. Average performances on TOMM Trial 1 (36.62 vs 47.91, p<.001) and TOMM Trial 2 (37.50 vs 49.71, p<.001) were significantly lower in the SIM group. Performance on SGT was also significantly lower in the SIM group across SGT Total Correct (20.17 vs 24.65 of 40, p=.008), SGT Easy (10.60 vs 13.52 of 20, p=.002), and SGT Hard (9.57 vs 11.13 of 20, p=.068). Mixed ANOVA showed a trend towards significant group by SGT difficulty interaction (F(1,86)=3.41, p=.052, np2=.043). There was steeper decline in performance on SGT Hard compared to SGT Easy for CON. ROC analyses suggested adequate but not ideal sensitivity/specificity: scores <8 on SGT Easy (sensitivity=26%; false positive=11%), <7 on SGT Hard (sensitivity=26%; false positive=7%), and <15 on SGT Total (sensitivity=24%; false positive=9%). Conclusions: These preliminary data indicate the SGT may be able to detect malingered TBI. However, additional development of this measure is necessary. Further refinement of difficulty level may improve sensitivity/specificity (e.g., CON mean performance for SGT Easy trails was 13.52, suggesting the items may be too difficult). This study was limited to an online administration due to COVID, which could have affected results; future studies should test inperson administration of the SGT. In addition, performance in clinical control groups (larger samples of individuals with mild TBI, ADHD) should be tested to better determine specificity for these preliminary cutoffs. [ABSTRACT FROM AUTHOR]

The Word Memory Test (WMT) assesses non-credible performance in neuropsychological assessment. To mitigate risk of false positives among patients with severe cognitive dysfunction, the Genuine Memory Impairment Profile was derived. Only a modest number of investigations has evaluated classification accuracy among clinical samples, leaving the GMIP's accuracy largely uncertain. Accordingly, a simulation experiment evaluated the classification accuracy of the GMIP in a group of healthy individuals coached to simulate mild traumatic brain injury (TBI) related memory impairment on the WMT. Eighty healthy individuals were randomly assigned to one of the four experimental groups. One group was provided superficial information concerning TBI symptoms (naïve simulators), another was provided extensive information concerning TBI symptoms (sophisticated simulators), and a third group was provided extensive TBI symptom information and tactics to evade detection by performance validity tests (PVT) (test-coached). An honest responding control group was directed to give their best performance. All participants were administered the California Verbal Learning Test-2 (CVLT-2) and the WMT. Among the TBI simulators, 90% of the test-coached, 95% of the sophisticated simulators, and 100% of the naïve simulators were correctly classified as exaggerating memory impairment on the primary WMT indices. The simulator groups performed worse than the honest responding group on the CVLT-2. Of those who exceeded the WMT cutoffs, 60%, 27%, and 6% of the naïve-, sophisticated-, and test-coached simulators manifested the GMIP profile, respectively. The GMIP is apt to misclassify individuals as having genuine memory impairment, especially if a naïve or unsophisticated effort is made to exert non-credible performance. Indeed, individuals who employ the least sophisticated efforts to exaggerate cognitive impairment appear most likely to manifest the GMIP. The GMIP should be used cautiously to discriminate genuine impairment from non-credible performance, especially among people with mild TBI. [ABSTRACT FROM AUTHOR]

Introduction: The Groningen Effort Test (GET) is a recently developed performance validity test (PVT) for the identification of noncredible performance in a neuropsychological assessment of attention abilities. Because the majority of already established PVTs are based on memory functions, the GET has the potential to make a valuable contribution to validity testing. Method: The current study examined the utility of the GET in the detection of feigned cognitive dysfunction after acquired brain injury (ABI) and its incremental validity over already established PVTs, namely the Test of Memory Malingering (TOMM), the Dot Counting Test (DCT), and the b Test. Three hundred and forty-eight participants took part in this study, including 58 patients with ABI (stroke or traumatic brain injury), 43 healthy individuals instructed to show normal behavior, and 247 healthy individuals instructed to feign cognitive dysfunction after ABI. Results: With excellent overall classification accuracy, the GET performed close to the level of the TOMM, and superior to the b Test and DCT. Data analyses further revealed that the GET provides additional diagnostic accuracy compared to the b Test and the DCT in the detection of feigned cognitive dysfunction, but has no incremental validity over the TOMM. For each of the four PVTs in this study, diagnostic sensitivity was independent of the simulation strategy used. Conclusions: It is concluded that the GET is an attention-based PVT with promising test characteristics and high diagnostic accuracy in the detection of noncredible cognitive performance using a simulation design. Given the results can be replicated in studies using known-groups methodology, it may be a useful tool for clinical practice to complement neuropsychological assessments of patients with ABI. [ABSTRACT FROM AUTHOR]