Neurocognitive variables underlying group performance on a measure of effort: The Medical Symptom Validity Test (MSVT)
This study utilized the Medical Symptom Validity Test (MSVT) and a set of standard neuropsychological instruments to determine the underlying construct of the MSVT that accounts for effort in mild traumatic brain injury (mTBI) patients by comparing/contrasting mTBI with dementia and an analog simulation. The results indicate that a common underlying neurocognitive construct (memory) exists between mTBI and dementia patients, which may account for poor effort as measured by the MSVT. Other underlying factors emerged for both groups, though they did not point to a common construct. This finding suggests that the overall effect of brain injury in neurologically impaired groups also impacts effort performance as measured by the MSVT. Similarly impaired performance patterns also emerged between mTBI and dementia groups in sub groups that failed effort measures. Thus, failed effort tests may be a function of more pronounced deficits in these groups, rather than a function of effort. Finally, although similar effort profiles were noted between mTBI and analog simulators, the analog group was unable to mimic the neurocognitive effects of mTBI.