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Objective: Pupillometry provides information about physiological and psychological processes related to cognitive load, familiarity, and deception, and it is outside of conscious control. This study examined pupillary dilation patterns during a performance validity test (PVT) among adults with true and feigned impairment of traumatic brain injury (TBI)., Participants and Methods: Participants were 214 adults in three groups: adults with bona fide moderate to severe TBI (TBI; n  = 51), healthy comparisons instructed to perform their best (HC; n  = 72), and healthy adults instructed and incentivized to simulate cognitive impairment due to TBI (SIM; n  = 91). The Recognition Memory Test (RMT) was administered in the context of a comprehensive neuropsychological battery. Three pupillary indices were evaluated. Two pure pupil dilation (PD) indices assessed a simple measure of baseline arousal (PD-Baseline) and a nuanced measure of dynamic engagement (PD-Range). A pupillary-behavioral index was also evaluated. Dilation-response inconsistency (DRI) captured the frequency with which examinees displayed a pupillary familiarity response to the correct answer but selected the unfamiliar stimulus (incorrect answer)., Results: All three indices differed significantly among the groups, with medium-to-large effect sizes. PD-Baseline appeared sensitive to oculomotor dysfunction due to TBI; adults with TBI displayed significantly lower chronic arousal as compared to the two groups of healthy adults (SIM, HC). Dynamic engagement (PD-Range) yielded a hierarchical structure such that SIM were more dynamically engaged than TBI followed by HC. As predicted, simulators engaged in DRI significantly more frequently than other groups. Moreover, subgroup analyses indicated that DRI differed significantly for simulators who scored in the invalid range on the RMT ( n  = 45) versus adults with genuine TBI who scored invalidly ( n  = 15)., Conclusions: The findings support continued research on the application of pupillometry to performance validity assessment: Overall, the findings highlight the promise of biometric indices in multimethod assessments of performance validity.

Neuropsychological test interpretation rests upon the assumption that the examinee has exerted full effort. If an individual provides inadequate effort during exam, the resulting data will be invalid and represent an underestimate of the person's true abilities. Although youth have been assumed historically to be less capable of deception than adults, acts of deception in childhood are not uncommon, even in normative populations. Yet, very few cases of children who have provided suboptimal effort during neuropsychological exam have appeared in the scientific literature. We present six clinical cases illustrating that children down to at least age 8 years can present with noncredible performance. The cases include those in which clear external incentives could be identified to those in which intrinsic or psychological factors were presumed to predominate. The fairly diverse nature of the presented cases, along with other recent work, suggests that suboptimal effort in children is apt to occur more frequently than previously recognized, even if it might occur less often than in comparable adult samples. In most of the presented cases, noncredible performance would not have been detected definitively by clinical judgment alone, reinforcing the value of routinely incorporating symptom validity tests into the neuropsychological assessment of school-aged children. The number of effort tests that have demonstrated utility in children pales in comparison to those available to the adult practitioner, although recent research now supports the use of several standalone measures with pediatric patients.

We studied a case of psychogenic amnesia by means of a functional magnetic resonance imaging (fMRI) experiment involving the retrieval of autobiographical memories. The 38-year-old patient was unable to access most of her autobiographical memories from her childhood up to 16 years of age. Compared with the forgotten period, evocation of the normally retrieved memories elicited increased activity in medial temporal and dorso-lateral frontal regions. Evocation of the preserved scattered recollections was associated with bilaterally distributed temporo-parieto-occipital loci of activations. These functional changes seem to support the idea of common mechanisms involved in both organic and psychogenic amnesias.

Validity scales were recently developed to improve assessment of symptom validity beyond original MMPI-2 validity scales. In an initial study, the Response Bias Scale (RBS; Gervais, 2005) was developed based upon non-head-injury claimant performances on a cognitive effort measure, the Word Memory Test (WMT). The present study examined relationships of the RBS with numerous MMPI-2 validity scales in a sample of 211 participants with secondary gain (SG) or no secondary gain (NSG). Of the validity scales observed, RBS yielded the largest effect size difference between groups (d = .65), followed closely by FBS (d = .60) and the L-scale (d = .51). Overall, RBS correlated most significantly (r = .74, p < .001) with FBS, but also showed significant correlations with most other validity scales for both groups. RBS further demonstrated significant correlations (p < .001) with all clinical scales except for Mf. Findings suggest that RBS and FBS may represent a similar construct of symptom validity, and may outperform other MMPI-2 validity scales in discriminating SG and NSG groups. Findings provide preliminary support for use of RBS within the forensic context.

The purpose of this study was to examine the clinical utility of memory minus Working Memory Index (memory-WMI) discrepancy scores on the WMS-III for detecting poor effort in 145 personal injury litigants (19 poor effort, 126 adequate effort). On average, participants in the poor effort group performed significantly lower on all WMS-III memory indexes and demonstrated larger memory-WMI discrepancy scores compared to participants in the adequate effort group. Discriminant function analyses using memory-WMI discrepancy scores as independent variables revealed poor overall classification rates (60.0% to 63.4%). Based on the prevalence of unusually suppressed attention-concentration ability relative to memory functioning using unidirectional memory-WMI discrepancy scores, high specificity and negative predictive power values were found. However, there was unacceptably low sensitivity and positive predictive power. These results suggest that memory-WMI discrepancy scores on the WMS-III do not provide clinically useful information regarding response set and should be used cautiously as an indicator of poor effort.

Published information pertaining to the clinical utility of the WMS-III in assessing memory impairment in traumatic brain injury (TBI) remains inadequate. WMS-III findings are reported for 180 litigants with post-acute moderate to extremely severe TBI, classified into three groups according to injury severity, and a healthy control group. A significant "dose-response" relationship was found between memory impairment and TBI severity for most of the WMS-III indexes and subtests. Effect sizes were large for the Immediate and General Memory Indexes and medium for the Working Memory Index. In general, TBI had a greater effect on the Visual than Auditory Indexes. Effect sizes were greatest for Family Pictures and least for the auditory recognition and working memory tasks. Group findings indicate the immediate memory tasks to be clinically useful in relation to a severe or extremely severe TBI, but not for less severe trauma. Delayed memory tasks do not provide information additional to that obtained from immediate memory measures. The revised Tulsky indexes are no more sensitive to the effects of TBI than the original ones. Differences between WMS-III memory indexes are unlikely to be of diagnostic utility although memory-intelligence discrepancies may be.

Recent research suggests that effort detection measures based on patterns of neuropsychological performance may be more robust to coaching than traditional effort detection measures. In the present study, we evaluated the Exaggeration Index for an extended version of the Auditory Verbal Learning Test (EI-AVLTX), a recently developed effort detection instrument based on patterns of performance on the AVLT using a simulated malingering paradigm. In two independent samples, the EI-AVLTX was1 found to be relatively sensitive and specific to malingering, and robust to the effects of a warning about malingering detection.

The current study is an investigation of the MMPI-2 Fake Bad Scale ( FBS ) in the detection of incomplete effort in mild head injury (MHI). Using ROC curve analysis, we found that a cutoff score of 21 had a sensitivity of 90% and specificity of 90%, providing an overall correct classificatory rate of 90%. In addition, traditional indices of faking bad on the MMPI-2, the F and F-K indices, fared relatively poorly by comparison and added no predictive power over the FBS. Finally, multivariate analyses revealed that although the FBS shares a number of items with Hs and Hy scales, the FBS carried the majority of variance in predicting incomplete effort in our MHI sample. Overall, these findings indicate that the FBS has high sensitivity and specificity in identifying incomplete effort in mild head injury.

Three studies describe the development and validation of a new procedure (AVLTX) to detect inadequate effort or malingering by adding 60-min delayed recall/recognition trials and identifying "impaired" memory performances that are highly inconsistent with performances of brain-damaged (BD) individuals. In Study I, AVLTX performances of 25 probable malingerers (PMs) were compared with those of 43BD and 40 psychiatric patients (PSYs). Seven inconsistencies were identified and converted to scaled inconsistency scores, yielding the exaggeration index (EI). Study II reported cross-validation in an independent sample of 34 PM, 70BD and 89 PSY, showing sensitivity of 0.59 and specificities of 0.97 (BD) and 0.92 (PSY). Study III compared the diagnostic accuracy of the EI with two well-established effort assessment paradigms, exemplified by the RMTand DRT (a symptom validity test). The RMT showed excellent sensitivity and poor specificity; the DRT showed poor sensitivity and excellent specificity; the EI showed good sensitivity and excellent specificity. Adding a second delayed trial to list-learning tests can be a time-efficient procedure to detect inadequate effort.

Neuropsychological testing was completed in a patient who showed cognitive decline of mental functions, unusual answers to questions, and other characteristics of what has typically been described in the literature as the "Ganser Syndrome." Clear evidence of malingering on a memory test seemed to confirm that this patient was exaggerating deficits for psychiatric reasons or secondary gain, yet the patient showed evidence of mild organic impairment on MRI and continued to deteriorate in cognitive functions and basic self-care. Although an initial SPECT scan had suggested a pattern inconsistent with dementia, a second scan showed frontal-temporal perfusion deficits. Based on this scan and the clinical picture of progressive deterioration, a diagnosis of frontal-temporal lobe dementia was made. This case illustrates that the seemingly deliberate selection of incorrect responses may occur in the early stages of an organic dementia, and that a diagnosis of frontal-temporal lobe dementia should be considered in cases where symptoms appear to be psychiatric or nonorganic. The case further raises the question of whether the reported symptoms of Ganser Syndrome may be accounted for by frontal-temporal lobe dysfunction, since there appears to be some overlap between symptoms of Ganser Syndrome and frontal-temporal lobe dementia. It is also important to note that many reported cases of Ganser Syndrome had a history of head injury.