Word Memory Test Performance Across Cognitive Domains, Psychiatric Presentations, and Mild Traumatic Brain Injury

The classification accuracy of Warrington's recognition memory test (words) as a performance validity Test in a neurorehabilitation setting

This study was designed to evaluate the classification accuracy of the Warrington's Recognition Memory Test (RMT) in 167 patients (97 or 58.1% men; MAge = 40.4; MEducation= 13.8) medically referred for neuropsychological evaluation against five psychometrically defined criterion groups. At the optimal cutoff (≤42), the RMT produced an acceptable combination of sensitivity (.36-.60) and specificity (.85-.95), correctly classifying 68.4-83.3% of the sample. Making the cutoff more conservative (≤41) improved specificity (.88-.95) at the expense of sensitivity (.30-.60). Lowering the cutoff to ≤40 achieved uniformly high specificity (.91-.95) but diminished sensitivity (.27-.48). RMT scores were unrelated to lateral dominance, education, or gender. The RMT was sensitive to a three-way classification of performance validity (Pass/Borderline/Fail), further demonstrating its discriminant power. Despite a notable decline in research studies focused on its classification accuracy within the last decade, the RMT remains an effective free-standing PVT that is robust to demographic variables. Relatively low sensitivity is its main liability. Further research is needed on its cross-cultural validity (sensitivity to limited English proficiency).

Symptom and performance validity in neuropsychological assessments of outpatients 15-30 years of age

OBJECTIVE

It has been suggested that performance validity tests (PVTs) assess the credibility of a patient's objective test performance, symptom validity tests (SVTs) assess the credibility of a patient's subjective complaints, and that PVTs and SVTs are independent measures. The aim of this study was to test this hypothesis and investigate the associations of PVTs and SVTs with cognitive tests and self-reported measures.

METHOD

Patients 15-30 years of age were consecutively recruited from a neurorehabilitation outpatient clinic. The participants completed a battery of cognitive tests and self-reporting questionnaires as well as the Test of Memory Malingering (TOMM) and the Structured Inventory of Malingered Symptomatology (SIMS).

RESULTS

Forty-eight neurological patients of various etiologies were included. The TOMM (PVT) was related to cognitive tests across cognitive domains and unrelated to self-reporting measures. The SIMS (SVT) was related to other self-reported measures of perceived stress, anxiety, and depression, though also related to cognitive test of attention and processing speed. The PVT and the SVT were unrelated and hence seemed to measure two different constructs of validity.

CONCLUSIONS

This study supports the definition of PVTs and SVTs as two independent measures, consequently that both should be applied routinely in neuropsychological assessments.

Eye tracking as a mean to detect feigned cognitive impairment in the word memory test

Eye movements showed initial promise for the detection of deception and may be harder to consciously manipulate than conventional accuracy measures. Therefore, we integrated an eye-tracker with the Word Memory Test (WMT) and tested its usefulness for the detection of feigned cognitive impairment. As part of the study, simulators (n = 44) and honest controls (n = 41) performed WMT's immediate-recognition (IR) subtest while their eye movements were recorded. In comparison to the control group, simulators spent less time gazing at relevant stimuli, spent more time gazing at irrelevant stimuli, and had a lower saccade rate. Group classification using a scale that combined the eye movement measures and the WMT's accuracy measure showed tentative promise (i.e., it enhanced classification compared to the use of the accuracy measure as the sole predictor of group membership). Overall, integration of an eye-tracker with the WMT was found to be feasible and the eye movement measures showed initial promise for the detection of feigned cognitive impairment. Moreover, eye movement measures proved useful in enhancing our understanding of strategies utilized by the simulators and the cognitive processes that affect their behavior. While the findings are clearly preliminary, we hope that they will encourage further research of these promising psychophysiological measures.