Time and money: Exploring enhancements to performance validity research designs

Introduction The study examined the effect of preparation time and financial incentives on healthy adults' ability to simulate traumatic brain injury (TBI) during neuropsychological evaluation. Method A retrospective comparison of two TBI simulator group designs: a traditional design employing a single-session of standard coaching immediately before participation (SIM-SC; n = 46) and a novel design that provided financial incentive and preparation time (SIM-IP; n = 49). Both groups completed an ecologically valid neuropsychological test battery that included widely-used cognitive tests and five common performance validity tests (PVTs). Results Compared to SIM-SC, SIM-IP performed significantly worse and had higher rates of impairment on tests of processing speed and executive functioning (Trails A and B). SIM-IP were more likely than SIM-SC to avoid detection on one of the PVTs and performed somewhat better on three of the PVTs, but the effects were small and non-significant. SIM-IP did not demonstrate significantly higher rates of successful simulation (i.e., performing impaired on cognitive tests with <2 PVT failures). Overall, the rate of the successful simulation was similar to 40% with a liberal criterion, requiring cognitive impairment defined as performance >1 SD below the normative mean. At a more rigorous criterion defining impairment (>1.5 SD below the normative mean), successful simulation approached 35%. Conclusions Incentive and preparation time appear to add limited incremental effect over traditional, single-session coaching analog studies of TBI simulation. Moreover, these design modifications did not translate to meaningfully higher rates of successful simulation and avoidance of detection by PVTs.