Search

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.

Objective: This study was designed to examine the classification accuracy of verbal fluency (VF) measures as performance validity tests (PVT). Method: Student volunteers were assigned to the control ( n  = 57) or experimental malingering ( n  = 24) condition. An archival sample of 77 patients with TBI served as a clinical comparison. Results: Among students, FAS T-score ≤29 produced a good combination of sensitivity (.40-.42) and specificity (.89-.95). Animals T-score ≤31 had superior sensitivity (.53-.71) at .86-.93 specificity. VF tests performed similarly to commonly used PVTs embedded within Digit Span: RDS ≤7 (.54-.80 sensitivity at .93-.97 specificity) and age-corrected scaled score (ACSS) ≤6 (.54-.67 sensitivity at .94-.96 specificity). In the clinical sample, specificity was lower at liberal cutoffs [animals T-score ≤31 (.89-.91), RDS ≤7 (.86-.89) and ACSS ≤6 (.86-.96)], but comparable at conservative cutoffs [animals T-score ≤29 (.94-.96), RDS ≤6 (.95-.98) and ACSS ≤5 (.92-.96)]. Conclusions: Among students, VF measures had higher signal detection performance than previously reported in clinical samples, likely due to the absence of genuine impairment. The superior classification accuracy of animal relative to letter fluency was replicated. Results suggest that existing validity cutoffs can be extended to cognitively high functioning examinees, and emphasize the importance of population-specific cutoffs.

Objective: Iraq and Afghanistan Veterans with posttraumatic stress disorder (PTSD) and traumatic brain injury (TBI) history have high rates of performance validity test (PVT) failure. The study aimed to determine whether those with scores in the invalid versus valid range on PVTs show similar benefit from psychotherapy and if psychotherapy improves PVT performance., Method: Veterans (N = 100) with PTSD, mild-to-moderate TBI history, and cognitive complaints underwent neuropsychological testing at baseline, post-treatment, and 3-month post-treatment. Veterans were randomly assigned to cognitive processing therapy (CPT) or a novel hybrid intervention integrating CPT with TBI psychoeducation and cognitive rehabilitation strategies from Cognitive Symptom Management and Rehabilitation Therapy (CogSMART). Performance below standard cutoffs on any PVT trial across three different PVT measures was considered invalid (PVT-Fail), whereas performance above cutoffs on all measures was considered valid (PVT-Pass)., Results: Although both PVT groups exhibited clinically significant improvement in PTSD symptoms, the PVT-Pass group demonstrated greater symptom reduction than the PVT-Fail group. Measures of post-concussive and depressive symptoms improved to a similar degree across groups. Treatment condition did not moderate these results. Rate of valid test performance increased from baseline to follow-up across conditions, with a stronger effect in the SMART-CPT compared to CPT condition., Conclusion: Both PVT groups experienced improved psychological symptoms following treatment. Veterans who failed PVTs at baseline demonstrated better test engagement following treatment, resulting in higher rates of valid PVTs at follow-up. Veterans with invalid PVTs should be enrolled in trauma-focused treatment and may benefit from neuropsychological assessment after, rather than before, treatment.

Objective: Temporal discounting describes the devaluation of delayed rewards. Because temporal discounting is predictive of substance misuse, its clinical assessment could improve prevention (e.g., identifying at-risk youth) and treatment (e.g., predicting relapse). However, if discounting rates can be faked (e.g., to avoid treatment), their clinical utility may be limited. For the first time, we measured the influence of deception in a temporal discounting task., Method: We recruited 200 participants (44% female, M age = 33) through Amazon Mechanical Turk. Participants completed a discounting assessment with instructions to (a) respond honestly, (b) fake good (i.e., simulate better versions of themselves), or (c) fake bad., Results: Generalized linear mixed effects analysis showed that in Experiment 1, nonclinical samples faked good ( M hyperbolic discounting rate = 0.002) or bad ( M =   0.086) compared to the Honest group ( M = 0.008). In Experiment 2, cigarette smokers faked good ( M = 0.003) compared to the Honest group ( M =  0.025)., Conclusions: Temporal discounting transects the disciplines of psychology, biology, and behavioral economics. Before its promise as an endophenotype can be realized, assessments must be translated for clinical use. Opaquer temporal discounting tasks, or secondary measures of lying, may be required before temporal discounting can be confidently extended to clinical settings., (© 2019 Wiley Periodicals, Inc.)

The Forced Choice Test (FCT) can be used to detect malingered loss of memory or sensory deficits. In this test, examinees are presented with two stimuli, one correct and one incorrect, in regards to a specific event or a perceptual discrimination task. The task is to select the correct answer alternative, or guess if it is unknown. Genuine impairment is associated with test scores that fall within chance performance. In contrast, malingered impairment is associated with purposeful avoidance of correct information, resulting in below chance performance. However, a substantial proportion of malingerers intentionally randomize their responses, and are missed by the test. Here we examine whether a 'runs test' and a 'within test response 'bias' have diagnostic value to detect this intentional randomization. We instructed 73 examinees to malinger red/green blindness and subjected them to a FCT. For half of the examinees we manipulated the ambiguity between answer alternatives over the test trials in order to elicit a response bias. Compared to a sample of 10,000 cases of computer generated genuine performance, the runs test and response bias both detected malingered performance better than chance.

Background: We investigated a simple, novel diagnostic test for detecting incomplete effort during the motor portion of the neurological examination., Methods: The results from the honest palm sign (HPS) were evaluated for 162 consecutive neuro-oncology patients who had undergone upper extremity strength testing. Deltoid, bicep, and wrist extensor strength was assessed in all patients. During the examination, patients were repeatedly encouraged to "try as hard as possible" and to "resist with all your strength." The absence of nail prints on the palms constituted a positive HPS test result (i.e., indicative of incomplete effort). The presence of nail prints constituted a negative HPS test result (i.e., indicative of full effort)., Results: A total of 162 patients were tested. Their mean age was 55.5 ± 14.9 years, the median Karnofsky performance scale score was 80 (range, 60-100), and 63 patients (39%) were men. Of the 162 patients, 102 (63%) had malignant gliomas, 28 (17%) had brain metastases, 21 (13%) had other primary brain tumors, and 11 (6.8%) had primary central nervous system lymphomas. Of the 162 patients, 48 (30%) had positive HPS test results. The test sensitivity (84.6%), specificity (75.2%), positive likelihood ratio (3.41), and negative likelihood ratio (0.205) were good. After excluding 33 patients with characteristics that rendered them unsuitable for testing, the results from the remaining 129 patients were analyzed. The sensitivity was unchanged (84.6%), but the specificity (96.6%), positive likelihood ratio (24.5), and negative likelihood ratio (0.16) improved dramatically., Conclusions: The HPS test is a simple, sensitive, and very specific test for detecting incomplete effort during the motor portion of neurological evaluations., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Key elements for understanding, assessing, and treating a patient with a complaint of chemosensory dysfunction include establishing a relevant medical history and performing a focused medical examination. This age-old medical approach combines the utilization of associated tests and the results of chemosensory testing to establish a diagnosis and plan for medical management. Chemosensory testing is critical to establish the degree of dysfunction, the veracity and accuracy of a patient's self-report, the efficacy of treatments, and the degree to which spontaneous recovery occurs. In common with most medical disorders, it is incumbent upon the physician to determine, as best as possible, the time of onset of the symptom, its severity, precipitating factors, comorbidities, and fluctuations over time to understand the underlying pathophysiology. Importantly, distinguishing between "taste" loss due to decreased flavor sensations secondary to olfactory system compromise and "taste" loss due to true taste bud-mediated sensory alterations is critical. Unfortunately, this distinction is often underappreciated by medical professionals and laypersons alike, resulting in needless referrals within the medical community, including those related to imaging and gastroenterological testing. This chapter outlines the basic elements of the medical history and assessment of patients with complaints of chemosensory dysfunction, including a discussion on how to detect malingering., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Objectives: The aim of this study was to investigate the relationship of psychological variables to cognitive performance validity test (PVT) results in mixed forensic and nonforensic clinical samples., Methods: Participants included 183 adults who underwent comprehensive neuropsychological examination. Criterion groups were formed, that is, Credible Group or Noncredible Group, based upon their performance on the Word Memory Test and other stand-alone and embedded PVT measures., Results: Multivariate logistic regression analysis identified three significant predictors of cognitive performance validity. These included two psychological constructs, for example, Cogniphobia (perception that cognitive effort will exacerbate neurological symptoms), and Symptom Identity (perception that current symptoms are the result of illness or injury), and one contextual factor (forensic). While there was no interaction between these factors, elevated scores were most often observed in the forensic sample, suggesting that these independently contributing intrinsic psychological factors are more likely to occur in a forensic environment., Conclusions: Illness perceptions were significant predictors of cognitive performance validity particularly when they reached very elevated levels. Extreme elevations were more common among participants in the forensic sample, and potential reasons for this pattern are explored. (JINS, 2018, 24, 735-745).

The symptoms of ADHD are highly subjective, and there is ample empirical evidence that demonstrates the ease with which impairments in attention can be feigned on many commonly used subjective and objective measures of attention. We examined the combination of two assessment measures, NV-MSVT and IVA+, to screen for performance validity and ADHD symptoms in college students. Results indicated that the NV-MSVT was effective in differentiating between students with potential high impairment, such as ADHD, and possible malingerers. In addition, in vivo clinical data (N = 350) resulted in lower validity cut-off scores on the IVA+ than had been previously suggested. Clinical implications and future research are also discussed.

Detecting submaximal effort when testing grip strength is difficult. Research so far has focused on the discrimination between sincere and feigning healthy participants, whereas the clinically relevant distinction is between injured patients and feigning participants. The aim of our study was to compare rapid exchange grip and isometric grip strength testing in 41 participants feigning weakness with 39 patients with decreased hand function. Various parameters that describe grip strength were recorded and tested for differences between the groups. Only the maximum grip strength during rapid exchange grip was found to be significantly higher in feigning participants compared with patients, but this cannot be used for decision-making on an individual basis. We found no parameters that are useful for the detection of feigned weakness in an individual case., Level of Evidence: III.

This chapter is aimed at highlighting the recent findings concerning physiopathology, diagnosis, and management of conversion, factitious disorder, and malingering. Conversion disorder is the unintentional production of neurological symptom, whereas malingering and factitious disorder represent the voluntary production of symptoms with internal or external incentives. They have a close history and this has been frequently confounded. Practitioners are often confronted to medically unexplained symptoms; they represent almost 30% of neurologist's consultation. The first challenge is to detect them, and recent studies have confirmed the importance of "positive" clinical bedside signs based on incoherence and discordance, such as the Hoover's sign for the diagnosis of conversion disorder. Functional neuroimaging has allowed a better understanding of the pathophysiology, and highlighted abnormal cerebral activation patterns in conversion disorder in relation to motor, emotional, and limbic networks, different from feigners. This supports the theory evoked by Charcot of a "psychodynamic lesion," which is also reflected by the new term introduced in the DSM-5: functional neurological disorder. Multidisciplinary therapy is recommended with behavioral cognitive therapy, antidepressant to treat frequent comorbid anxiety or depression, and physiotherapy. Factitious disorder and malingering should be clearly delineated from conversion disorder. Factitious disorder should be considered as a mental illness and more research on its physiopathology and treatment is needed, when malingering is a non-medical condition encountered in medico-legal cases., (© 2018 S. Karger AG, Basel.)

The dancing mania erupted in the 14th century in the wake of the Black Death, and recurred for centuries in central Europe - particularly Germany, the Netherlands, and Belgium - finally abating in the early 17th century. The term "dancing mania" was derived from "choreomania," a concatenation of choros (dance) and mania (madness). A variant, tarantism, was prevalent in southern Italy from the 15th to the 17th centuries, and was attributed at the time to bites from the tarantula spider. Affected individuals participated in continuous, prolonged, erratic, often frenzied and sometimes erotic, dancing. In the 14th century, the dancing mania was linked to a corruption of the festival of St. John's Day by ancient pagan customs, but by the 16th century it was commonly considered an ordeal sent by a saint, or a punishment from God for people's sins. Consequently, during outbreaks in the 14th and 15th centuries, the dancing mania was considered an issue for magistrates and priests, not physicians, even though the disorder proved intractable to decrees and exorcisms. However, in the 16th century Paracelsus discounted the idea that the saints caused or interceded in the cure of the dancing mania; he instead suggested a psychogenic or malingered etiology, and this reformulation brought the dancing mania within the purview of physicians. Paracelsus advocated various mystical, psychological, and pharmacological approaches, depending on the presumptive etiologic factors with individual patients. Only music provided any relief for tarantism. Later authors suggested that the dancing mania was a mass stress-induced psychosis, a mass psychogenic illness, a culturally determined form of ritualized behavior, a manifestation of religious ecstasy, or even the result of food poisoning caused by the toxic and psychoactive chemical products of ergot fungi. In reality, dancing manias did not have a single cause, but component causes likely included psychogenic illness, malingering, and ritualized behaviors., (© 2018 S. Karger AG, Basel.)

Background and Objective: Initiation of response in a simple reaction time (RT) task may precede conscious perception of the stimulus. Since volitionally delayed responses may require conscious perception of the stimulus before response initiation, it has been hypothesized that volitionally delayed responses will markedly delay RT., Methods: We conducted two experiments with separate groups of healthy volunteers (n=16; n=13) who performed computerized simple and choice RT tasks. In the standard condition, we instructed the participants to respond to a visual stimulus by pushing a button as quickly as possible. In the second condition, we instructed the participants to respond after a slight volitional delay. The second experiment had an additional volitional delay condition in which we asked participants to delay their responses by an estimated 50% above their usual standard response., Results: We found marked delays and increased variability when participants volitionally delayed their responses, averaging 322 ms for standard and 861 ms for delayed simple RTs (267% increase), and 650 ms for standard and 1018 ms for delayed choice RTs (157% increase). Effects did not differ across age, sex, or handedness. However, a minority of participants did not meaningfully delay their RT during the volitional delay conditions., Conclusions: On average, participants had marked delays when they tried to delay their responses slightly, but a subset of participants exhibited essentially no delay despite trying to delay. We suggest some potential mechanisms that future investigations might delineate.

Purpose: To propose a new test to identify color vision deficiency malingering., Methods: An online survey was distributed to 130 truly color vision deficient participants and 160 participants willing to simulate color vision deficiency. The survey contained three sets of six color-adjusted versions of the standard Ishihara color plates each, as well as one set of six control plates. The plates that best discriminated both participant groups were selected for a "balanced" test emphasizing both sensitivity and specificity. A "specific" test that prioritized high specificity was also created by selecting from these plates. Statistical measures of the test (sensitivity, specificity, and Youden index) were assessed at each possible cut-off threshold, and a receiver operating characteristic (ROC) function with its area under the curve (AUC) charted., Results: The redshift plate set was identified as having the highest difference of means between groups (-58%, CI: -64 to -52%), as well as the widest gap between group modes. Statistical measures of the "balanced" test show an optimal cut-off of at least two incorrectly identified plates to suggest malingering (Youden index: 0.773, sensitivity: 83.3%, specificity: 94.0%, AUC of ROC 0.918). The "specific" test was able to identify color vision deficiency simulators with a specificity of 100% when using a cut-off of at least two incorrectly identified plates (Youden index 0.599, sensitivity 59.9%, specificity 100%, AUC of ROC 0.881)., Conclusions: Our proposed test for identifying color vision deficiency malingering demonstrates a high degree of reliability with AUCs of 0.918 and 0.881 for the "balanced" and "specific" tests, respectively. A cut-off threshold of at least two missed plates on the "specific" test was able to identify color vision deficiency simulators with 100% specificity.

In verbal fluency (VF) tests, subjects articulate words in a specified category during a short test period (typically 60 s). Verbal fluency tests are widely used to study language development and to evaluate memory retrieval in neuropsychiatric disorders. Performance is usually measured as the total number of correct words retrieved. Here, we describe the properties of a computerized VF (C-VF) test that tallies correct words and repetitions while providing additional lexical measures of word frequency, syllable count, and typicality. In addition, the C-VF permits (1) the analysis of the rate of responding over time, and (2) the analysis of the semantic relationships between words using a new method, Explicit Semantic Analysis (ESA), as well as the established semantic clustering and switching measures developed by Troyer et al. (1997). In Experiment 1, we gathered normative data from 180 subjects ranging in age from 18 to 82 years in semantic ("animals") and phonemic (letter "F") conditions. The number of words retrieved in 90 s correlated with education and daily hours of computer-use. The rate of word production declined sharply over time during both tests. In semantic conditions, correct-word scores correlated strongly with the number of ESA and Troyer-defined semantic switches as well as with an ESA-defined semantic organization index (SOI). In phonemic conditions, ESA revealed significant semantic influences in the sequence of words retrieved. In Experiment 2, we examined the test-retest reliability of different measures across three weekly tests in 40 young subjects. Different categories were used for each semantic ("animals", "parts of the body", and "foods") and phonemic (letters "F", "A", and "S") condition. After regressing out the influences of education and computer-use, we found that correct-word z-scores in the first session did not differ from those of the subjects in Experiment 1. Word production was uniformly greater in semantic than phonemic conditions. Intraclass correlation coefficients (ICCs) of correct-word z-scores were higher for phonemic (0.91) than semantic (0.77) tests. In semantic conditions, good reliability was also seen for the SOI (ICC = 0.68) and ESA-defined switches in semantic categories (ICC = 0.62). In Experiment 3, we examined the performance of subjects from Experiment 2 when instructed to malinger: 38% showed abnormal (p< 0.05) performance in semantic conditions. Simulated malingerers with abnormal scores could be distinguished with 80% sensitivity and 89% specificity from subjects with abnormal scores in Experiment 1 using lexical, temporal, and semantic measures. In Experiment 4, we tested patients with mild and severe traumatic brain injury (mTBI and sTBI). Patients with mTBI performed within the normal range, while patients with sTBI showed significant impairments in correct-word z-scores and category shifts. The lexical, temporal, and semantic measures of the C-VF provide an automated and comprehensive description of verbal fluency performance., Competing Interests: DLW is affiliated with NeuroBehavioral Systems, Inc., the developers of Presentation software that was used to create these experiments. DLW’s affiliation with NBS does not alter our adherence to the data sharing policies of PLOS ONE.

Rationale: Artifacts or simulated diseases are self-inflicted conditions caused by various means and for different purposes. Disease simulation can be motivated, among other things, by illegal purposes, to escape from civil duties or prison sentences, for example, or to exploit specific situations in order to receive a range of benefits. In such cases, the simulator is fully aware of his or her actions and intentions., Diagnoses, Interventions and Outcomes: We report the case of a 42-year-old woman who, for 3 consecutive years, showed religious stigmata on the forehead and on the dorsal surface of hands and feet immediately before Easter. Lesions showed an acute onset, manifested as erosions and ulcerations, and healed a few days after Easter. Stigmata were immediately made public and every year faithful and curious people went in procession to the house of the patient, offering different kinds of gifts. After intervention of the police authority in the early days of the third episode, the patient and her family repented of their actions. Cutaneous lesions healed in few days and similar events did not occur during the following 2 years., Lessons: Regardless of personal beliefs, the possibility that stigmata could be self-inflicted for illegal or profit purposes should always be considered., Competing Interests: The authors have no conflicts of interest to disclose.

Purpose:: To investigate the contributions of transient pattern-reversal visual evoked potentials in the diagnosis of ocular malingering at a Brazilian university hospital., Methods:: Adult patients with suspected malingering in one or both eyes were referred for visual evoked potential testing. Data from patients' medical records were reviewed and analyzed retrospectively. Data analysis included the distance optotype visual acuity based on a ETDRS retro-illuminated chart and the transient pattern-reversal visual evoked potential parameters of latency (milliseconds) and amplitude (microvolts) for the P100 component, using checkerboards with visual subtenses of 15' and 60'. Motivations for malingering were noted., Results:: The 20 subjects included 11 (55%) women. Patient ages ranged from 21 to 61 years (mean= 45.05 ± 11.76 years; median= 49 years). In 8 patients (6 women), both eyes exhibited reduced visual acuity with normal pattern-reversal visually evoked potential parameters (pure malingerers). The remaining 12 patients (7 men) exhibited reduced vision in only 1 eye, with simulated reduced vision in the contralateral eye (exaggerators). Financial motivation was noted in 18 patients (9 men)., Conclusion:: Normal pattern-reversal visually evoked potential parameters with suspected ocular malingering were observed in a 20 patient cohort. This electrophysiological technique appeared to be useful as a measure of visual pathway integrity in this specific population.

Purpose: To investigate the efficacy of pattern visual evoked potentials (VEPs) in evaluating objective visual acuity (VA) and discriminating malingerers., Methods: Two hundred and forty-nine eyes of 249 patients aged 20-65 years were included. There were 147 eyes with macular diseases (group 1) and 102 eyes with optic nerve diseases (group 2). Amplitudes and latencies were analyzed and correlated with best-corrected visual acuity by a regression analysis. We found the best-correlated mode of pattern VEP, determined the relations, and then calculated the pattern VEP-estimated VA (PVEP-VA) of all 249 eyes, another 30 malingering eyes, 13 eyes with macular diseases, and 17 eyes with optic nerve diseases, and used a receiver operating characteristic (ROC) curve to determine a cutoff for acceptable variance between PVEP-VA and subjective VA to discriminate malingerers., Results: The best correlation was between the amplitude of 50' checkerboard size (Amp50') and VA in every group. Significant correlation was between Amp50' and VA, where p < 0.0001 in group 1 and p = 0.020 in group 2. A logarithmic curve best fitted the correlation in the regression analysis, where y = 1.731 - 1.569x (R(2) = 0.611, p < 0.0001) in group 1 and y = 2.413 - 2.169x (R(2) = 0.531, p < 0.0001) in group 2 [x: log(Amp50'), y: PVEP-VA (logMAR)]. By using the relations and ROC curve, we determined a variance value of 0.4041 (logMAR) with 100% sensitivity and 94.0% specificity in group 1 and 0.3658 with 70.6% sensitivity and 50.5% specificity in group 2 to discriminate malingerers., Conclusions: The pattern VEP amplitude of 50' checkerboard size was useful to assess VA and can be helpful in discriminating malingering from real disability.

Assessment of malingering has become an integral part of many neuropsychological evaluations, particularly in forensic settings. However, traditional malingering measures are known to be vulnerable to both manipulation and coaching. Consequently, recent research has attempted to identify physiological indices of cognitive functioning that are less susceptible to overt manipulation. While prior studies have explored the validity of physiological assessment of memory deficits, this study evaluates the effectiveness of a physiological measure of executive functioning. This study used EEG recording in conjunction with a three-stimulus oddball design to compare neural responses in simulated malingerers feigning cognitive deficits associated with traumatic brain injury (TBI) and controls. Specifically, the study explored the efficacy of an event-related potential (ERP) known as P3a, which is believed to be an index of frontal lobe executive processes, specifically the attentional orienting response. The results of this study demonstrated that simulated malingerers did not produce a P3a response that was significantly different from control participants. Furthermore, the P3a in simulated malingerers did not demonstrate any of the properties reported in prior studies with TBI patients. Not only were malingerers unable to produce a significant change in their basic orienting response, but the very process of attempting to employ additional strategies to appear impaired produced other physiological markers of deception. Therefore, the P3a component appeared to be unaffected by an individual's motivation or overt performance, which suggests that it may have potential for development as a physiological measure for differentiating between malingerers and those with genuine TBI., (Copyright © 2013 Elsevier B.V. All rights reserved.)

Objectives: To characterise patients diagnosed with fibromyalgia (FM) who present a clinical profile suggestive of simulation., Methods: Observational case-control study of 218 patients who met the classification criteria for FM. The profile supporting simulation was based on the proposed criteria for evaluating disability related to the simulation of pain., Results: Compared with controls (n=105), patients with suspected simulation of FM (n=106) had a higher mean age (52.5 vs. 49.2 years, p=0.003), a higher frequency of primary education (88.7% vs. 58.1%; p<0.001), a higher percentage of separated/widowed persons (33.9% vs. 8.6%, p<0.001), a higher frequency of psychiatric disorders (100% vs. 67.6%, p<0.001), a higher mean number of positive 'control' tender points (4.5 vs. 1.3, p<0.001), a higher mean FIQ questionnaire score (89.8 vs. 68.8, p<0.001) and a lower mean LHS questionnaire score (41.0 vs. 59.9, p<0.001). Patients with suspected simulation were able to walk a shorter distance in the 6-minute walk test than controls (231.0 vs. 356.3 metres, p<0.001), while the appearance of allodynia was achieved with a significantly lower mmHg pressure (159.8 vs. 229.9 mm Hg, p<0.001)., Conclusions: Some physical/functional tests, together with the administration of specific questionnaires, may identify a subgroup of patients with FM with a profile consistent with simulation or malingering; these patients have a differentiated demographic and psychiatric profile in comparison with FM patients without a profile of simulation.

In the assessment of human hearing, it is often important to determine whether hearing loss is organic or nonorganic in nature. Nonorganic, or functional, hearing loss is often associated with deceptive intention on the part of the listener. Over the past decade, functional neuroimaging has been used to study the neural correlates of deception, and studies have consistently highlighted the contribution of the prefrontal cortex in such behaviors. Can patterns of brain activity be similarly used to detect when an individual is feigning a hearing loss? To answer this question, 15 adult participants were requested to respond to pure tones and simple words correctly, incorrectly, randomly, or with the intent to feign a hearing loss. As predicted, more activity was observed in the prefrontal cortices (as measured by functional magnetic resonance imaging), and delayed behavioral reaction times were noted, when the participants feigned a hearing loss or responded randomly versus when they responded correctly or incorrectly. The results suggest that cortical imaging techniques could play a role in identifying individuals who are feigning hearing loss., (Copyright © 2011 Wiley Periodicals, Inc.)

Previous functional magnetic resonance imaging (fMRI) studies have identified activation in the prefrontal-parietal-sub-cortical circuit during feigned memory impairment when comparing with truthful telling. Here, we used fMRI to determine whether neural activity can differentiate between answering correctly, answering randomly, answering incorrectly, and feigned memory impairment. In this study, 12 healthy subjects underwent block-design fMRI while they performed digit task of forced-choice format under four conditions: answering correctly, answering randomly, answering incorrectly, and simulated feigned memory impairment. There were three main results. First, six areas, including the left prefrontal cortex, the left superior temporal lobe, the right postcentral gyrus, the right superior parietal cortex, the right superior occipital cortex, and the right putamen, were significantly modulated by condition type. Second, for some areas, including the right superior parietal cortex, the right postcentral gyrus, the right superior occipital cortex, and the right putamen, brain activity was significantly greater in feigned memory impairment than answering randomly. Third, for the areas including the left prefrontal cortex and the right putamen, brain activity was significantly greater in feigned memory impairment than answering incorrectly. In contrast, for the left superior temporal lobe, brain activity was significantly greater in answering incorrectly than feigned memory impairment. The results suggest that neural correlates of feigned memory impairment are distinguishable from answering randomly and answering incorrectly in healthy subjects., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Predictors of effort test failure were examined in an archival sample of 555 traumatically brain-injured (TBI) adults. Logistic regression models were used to examine whether compensation-seeking, injury-related, psychological, demographic, and cultural factors predicted effort test failure (ETF). ETF was significantly associated with compensation-seeking (OR = 3.51, 95% CI [1.25, 9.79]), low education (OR:. 83 [.74, . 94]), self-reported mood disorder (OR: 5.53 [3.10, 9.85]), exaggerated displays of behavior (OR: 5.84 [2.15, 15.84]), psychotic illness (OR: 12.86 [3.21, 51.44]), being foreign-born (OR: 5.10 [2.35, 11.06]), having sustained a workplace accident (OR: 4.60 [2.40, 8.81]), and mild traumatic brain injury severity compared with very severe traumatic brain injury severity (OR: 0.37 [0.13, 0.995]). ETF was associated with a broader range of statistical predictors than has previously been identified and the relative importance of psychological and behavioral predictors of ETF was evident in the logistic regression model. Variables that might potentially extend the model of ETF are identified for future research efforts.

During recognition memory tests participants' pupils dilate more when they view old items compared to novel items. We sought to replicate this "pupil old/new effect" and to determine its relationship to participants' responses. We compared changes in pupil size during recognition when participants were given standard recognition memory instructions, instructions to feign amnesia, and instructions to report all items as new. Participants' pupils dilated more to old items compared to new items under all three instruction conditions. This finding suggests that the increase in pupil size that occurs when participants encounter previously studied items is not under conscious control. Given that pupil size can be reliably and simply measured, the pupil old/new effect may have potential in clinical settings as a means for determining whether patients are feigning memory loss.

Objective: The aims of present research were to analyze the visually guided eye movements of subjects suffering from the consequences of whiplash injury and the possibility to differentiate patients from feigning subject. We analyzed the role of video-nystagmography for clinical and forensic aspects., Methods: It was a prospective case-control study. Detailed history was taken and patients were thoroughly investigated. Smooth pursuit and saccadic eye movements were assessed in 33 patients affected by imbalance following a whiplash injury. A control group of 20 subjects was also evaluated. All tests were executed in neutral neck position and after left and right trunk rotation., Results: The t-test, applied to all parameters showed that difference of the parameter between the groups was not statistically significant., Conclusion: The visually guided eye movement evaluation does not seem to offer a clinically relevant method to differentiate patients suffering from the effects of whiplash injury from normal subjects., (Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.)

Very little is known about the autonomic psychophysiological responses while individuals are executing a Symptom Validity Test. Therefore, the aim of this study is to analyze the peripheral psychophysiological correlates (electrodermal conductance and heart rate) during the performance of the Victoria Symptom Validity Test (VSVT). The sample of this study was composed of 30 participants who underwent the VSVT under two conditions: Exaggeration of cognitive deficits (ECD) and normal effort. Our results showed differences on skin conductance between correct answers and errors limited to the decision-making phase of the ECD condition. Those differences found in the maximum conductance value when participants decide to simulate their deficits could be related to emotional activation. No differences were found on the variable heart rate between the two conditions of the study. Implications of these results are discussed.

Although non-organic hearing losses are relatively rare, it is important to identify suspicious findings early to be able to administer specific tests, such as objective measurements and specific counseling. In this retrospective study, we searched for findings that were specific ti or typical for non-organic hearing losses. Patient records from a 6 year period (2003-2008) from the University ENT Department of Bern, Switzerland, were reviewed. In this period, 40 subjects were diagnosed with a non-organic hearing loss (22 children, ages 7-16, mean 10.6 years; 18 adults, ages 19-57, mean 39.7 years; 25 females and 15 males). Pure tone audiograms in children and adults showed predominantly sensorineural and frequency-independent hearing losses, mostly in the range of 40-60 dB. In all cases, objective measurements (otoacoustic emissions and/or auditory-evoked potentials) indicated normal or substantially better hearing thresholds than those found in pure tone audiometry. In nine subjects (22.5%; 2 children, 7 adults), hearing aids had been fitted before the first presentation at our center. Six children (27%) had a history of middle ear problems with a transient hearing loss and 11 (50%) knew a person with a hearing loss. Two new and hitherto unreported findings emerged from the analysis: it was observed that a small air-bone gap of 5-20 dB was typical for non-organic hearing losses and that speech audiometry might show considerably poorer results than expected from pure tone audiometry.

Psychogenic movement disorders (PMDs) are common, but their physiology is largely unknown. In most situations, the movement is involuntary, but in a minority, when the disorder is malingering or factitious, the patient is lying and the movement is voluntary. Physiologically, we cannot tell the difference between voluntary and involuntary. The Bereitschaftspotential (BP) is indicative of certain brain mechanisms for generating movement, and is seen with ordinarily voluntary movements, but by itself does not indicate that a movement is voluntary. There are good clinical neurophysiological methods available to determine whether myoclonus or tremor is a PMD. For example, psychogenic myoclonus generally has a BP, and psychogenic stimulus-sensitive myoclonus has a variable latency with times similar to normal reaction times. Psychogenic tremor will have variable frequency over time, be synchronous in the two arms, and might well be entrained with voluntary rhythmic movements. These facts suggest that PMDs share voluntary mechanisms for movement production. There are no definitive tests to differentiate psychogenic dystonia from organic dystonia, although one has been recently reported. Similar physiological abnormalities are seen in both groups. The question arises as to how a movement can be produced with voluntary mechanisms, but not be considered voluntary., (Published by Elsevier Ltd.)

Objectives/hypothesis: Smell and taste tests are commonly employed to quantify chemosensory sequelae of head trauma, toxic exposures, and iatrogenesis. Malingering on forced-choice chemosensory tests can be detected by improbable responding. This study determined whether chemosensory test malingerers differ from nonmalingerers in terms of age, sex, education, and a range of self-reported behaviors and symptoms, potentially providing information of value for malingering detection., Study Design: Case control., Methods: Twenty-two chemosensory malingerers were identified from a large clinical database and matched, randomly, to 66 nonmalingerers on the basis of etiology. Differences in demographics and responses to intake questionnaire items were statistically assessed. Logistic regression was used to identify variables that best predicted malingering behavior., Results: Relative to nonmalingerers, malingerers reported significantly fewer allergies, dental problems, cigarettes smoked, surgical operations, nasal sinus problems, and use of medications, and significantly more putative symptom-related psychological duress, interference with daily activities, weight loss, decreased appetite, and taste loss. Litigation involvement was higher in malingerers than nonmalingerers. Age, sex, education, and length of symptom descriptions did not differentiate malingerers from nonmalingerers., Conclusions: Malingerers of chemosensory tests exaggerate symptom severity and underreport factors that might be construed as contributing to their dysfunction, such as smoking behavior, medication use, and general health. This contrasts with the behavior of malingerers of psychiatric symptoms, who typically exaggerate their general health problems. These data suggest that careful review of past medical records should be used to verify patient reports to better detect chemosensory malingering in cases where financial or other external incentives are present.

Background: Illness deception (ID) may be difficult to detect. Objective techniques that improve a doctor's skills of detection will have benefits for the health economy., Aims: To ascertain the incidence of ID in a general occupational medicine clinic, to give examples by way of case vignettes how it may manifest and to compare the variability of maximal grip strength measurements of patients with suspected simulated weakness of grip with controls., Methods: Four hundred consecutive new patient referrals were examined by the author and those who met Diagnostic and Statistical Manual-IV criteria for factitious disorder (FD) or malingering identified. Those with suspected simulated weakness of grip were asked to perform three consecutive maximal grips with a Jamar hand dynamometer. One hundred normal subjects and 100 patients with rheumatoid arthritis (RA) of the hands were similarly tested., Results: Thirty-two of 400 (8%) patients exhibited behaviour in keeping with ID (29 malingering and 3 FD). Cases included simulated hand-arm vibration syndrome, occupational asthma, deafness and weakness of a limb. The median and 90th percentile for coefficient of variation (CV) of three consecutive maximal grip strengths for normal subjects and patients with RA were 5.2, 10.5%; 5.4, 14.5% right and 4.5, 10.2%; 6.0, 14.4% left hand, respectively. The CV of the six patients who simulated weakness of grip was from 17.3 to 37.8%., Conclusions: ID is relatively common in occupational medical practice and multiform in its manifestations. Simulated weakness of grip should be suspected when consecutive declared maximal grip strengths are inexplicably submaximal for age and sex and highly variable in force.

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.

A small percentage of people with a mild traumatic brain injury (MTBI) report persistent symptoms and problems many months or even years following injury. Preliminary research suggests that people who sustain an injury often underestimate past problems (i.e., "good old days" bias), which can impact their perceived level of current problems and recovery. The purpose of this study was to examine the influence of the good old bays bias on symptom reporting following MTBI. The MTBI sample consisted of 90 referrals to a concussion clinic (mean time from injury to evaluation = 2.1 months, SD = 1.5, range = 0.8-8.1). All were considered temporarily fully disabled from an MTBI and they were receiving financial compensation through the Worker's Compensation system. Patients provided post-injury and pre-injury retrospective ratings on the 16-item British Columbia Post-concussion Symptom Inventory (BC-PSI). Ratings were compared to 177 healthy controls recruited from the community and a local university. Consistent with the good old bays bias, MTBI patients retrospectively endorsed the presence of fewer pre-injury symptoms compared to the control group. Individuals who failed effort testing tended to retrospectively report fewer symptoms pre-injury compared to those patients who passed effort testing. Many MTBI patients report their pre-injury functioning as better than the average person. This can negatively impact their perception of current problems, recovery from injury, and return to work.

The central aim of this study was to evaluate the value of reaction time (RT) measures and event-related potentials (ERPs) for the assessment of simulated memory impairment. In two identical experiments (N=24), healthy volunteers carried out an adapted version of the Amsterdam Short-Term Memory (ASTM) test. In half of the cases participants were instructed to perform to their best of abilities (control condition) while in the other half participants were asked to feign a believable memory deficit (simulation condition). Compared to controls, simulating participants were found to produce longer and more variable RTs. In addition, they took longer to respond to new words than to old words, while control participants showed the opposite pattern. Both early (300-500 ms) and late (500-800 ms) ERP old/new effects were similar in magnitude and scalp distribution for both groups of participants, regardless of the fact that simulating participants had significantly lower recognition accuracy than controls. The ERP old/new effect was assumed to reflect unaffected retrieval mechanisms and thus the discrepancy between this measure and recognition performance was interpreted as evidence for intentional underperformance. Results are discussed in relation to clinical observations and deception detection studies. It was concluded that the combined use of RT and ERP measures could be useful to detect and evaluate simulation of memory impairment but that future studies should include patient groups to test some of our assumptions.

A known groups design investigated the comparative predictive validity of the 27-item MMPI-2 Restructured Scale 1 (RC1), the 43-item Lees-Haley Fake Bad Scale (FBS), and the 15-item Henry-Heilbronner Index (HHI) to identify noncredible symptom response sets in 63 personal injury litigants and disability claimants compared to 77 non-litigating head-injured controls. Logistic regression analyses revealed that the HHI and FBS were better predictors of group membership than the RC1. Results suggest that the FBS, HHI, and RC1 may be measuring different constructs. The HHI and FBS reflect an exaggeration of disability or illness-related behavior. Differences in scale construction are discussed. The RC1 may have greater relevance under external incentive conditions involving chronic pain patients, or clinical patients with no external incentive to exaggerate their symptom presentation.

Individual and joint malingering detection accuracy of the Portland Digit Recognition Test (PDRT), Test of Memory Malingering (TOMM), and Word Memory Test (WMT) was examined in traumatic brain injury (TBI; 43 non-malingering, 27 malingering) and chronic pain (CP; 42 non-malingering, 58 malingering) using a known-groups design. At published cutoffs, the PDRT and TOMM were very specific but failed to detect about 50% of malingerers; the WMT was sensitive but prone to false positive errors. ROC analyses demonstrated comparable accuracy across all three tests. Joint classification accuracy was superior to that of the individual tests. Clinical and research implications are discussed.

Study Design: Cross-sectional study of whiplash injury patients with vertigo and healthy volunteers consciously pretending to have postural sway as in malingering., Objective: The aim of this study was to evaluate the postural sway in malingerers by posturography., Summary of Background Data: Malingering is not a problem in the majority of cases with whiplash injury and diagnosis should be made carefully. However, some patients with whiplash injury might exaggerate their symptoms or be malingerers because of the potential gain associated with insurance claims. We designed a diagnostic study to screen putative malingerers., Methods: Subjects were 20 healthy volunteers who were tested under standing condition (normal group), consciously swaying the body under standing condition like malingerers (pseudomalingering group) and 32 patients who complained of neck pain with vertigo or dizziness after whiplash injury with WAD (whiplash-associated disorders) grade I and II (WAD group). The movement of the center of pressure (COP) was measured using a force platform to quantify postural sway. Static posturography was performed under open and closed eyes. We analyzed (1) total envelop area per unit of time (EAREA), (2) shifting length per second (LNG/TIME), (3) sway pattern, and (4) Romberg rate representing total shifting length under eyes-closed/eyes-open., Results: In open eyes condition, the values of EAREA and LNG/TIME were significant higher under pseudomalingering than both of the control and WAD groups (P < 0.05). The Romberg rate was 1.30 +/- 0.17, 1.13 +/- 0.19, and 1.83 +/- 0.94 in control, pseudo-malingering, and WAD group, respectively, and was less than 1.0 in 45% of pseudomalingering. There were significant differences in the EAREA, LEN/TIME, and Romberg rate between pseudomalingering and the other 2 groups (P < 0.05)., Conclusion: Our results suggest that compared with normal subjects and WAD patients, malingerers are more likely to exhibit a wide EAREA, a long sway length per second, and a low Romberg rate. Malingering must be diagnosed carefully and posturography could be a helpful supplementary tool for differentiating whiplash-associated vertigo from malingering.

Primary Objective: Event-related, functional magnetic resonance imaging (fMRI) data were acquired in healthy participants during purposefully malingered and normal recognition memory performances to evaluate the neural substrates of feigned memory impairment., Methods and Procedures: Pairwise, between-condition contrasts of neural activity associated with discrete recognition memory responses were conducted to isolate dissociable neural activity between normal and malingered responding while simultaneously controlling for shared stimulus familiarity and novelty effects. Response timing characteristics were also examined for any association with observed between-condition activity differences., Outcomes and Results: Malingered recognition memory errors, regardless of type, were associated with inferior parietal and superior temporal activity relative to normal performance, while feigned recognition target misses produced additional dorsomedial frontal activation and feigned foil false alarms activated bilateral ventrolateral frontal regions. Malingered response times were associated with activity in the dorsomedial frontal, temporal and inferior parietal regions. Normal memory responses were associated with greater inferior occipitotemporal and dorsomedial parietal activity, suggesting greater reliance upon visual/attentional networks for proper task performance., Conclusions: The neural substrates subserving feigned recognition memory deficits are influenced by response demand and error type, producing differential activation of cortical regions important to complex visual processing, executive control, response planning and working memory processes.

Prospects for the coexistence of post-traumatic stress syndrome (PTSS) and mild traumatic brain injury (mTBI) rely exclusively on subjective evidence, increasing the risk of response bias in a compensatable social context. Using a priori specificities derived from genuine brain disorder groups, we examined validity failure rates in three domains (symptom, cognitive, motor) in 799 persons reporting persistent subjective disability long after mild neurological injury. Validity tests included the Test of Memory Malingering, MMPI-2 Fake Bad Scale, and Infrequency (F) scales, reliable digit span, and Halstead-Reitan finger tapping. Analyses showed invalidity signs in large excess of actuarial expectations, with rising invalidity risk conditional on post-traumatic complexity; the highest failure rates were produced by the 95 persons reporting both neurogenic amnesia and re-experiencing symptoms. We propose an "over-endorsement continuum" hypothesis: The more complex the post-traumatic presentation after mild neurological injury, the stronger the association with response bias. Late-appearing dual diagnosis is a litigation phenomenon so intertwined with secondary gain as to be a byproduct of it.

Objective: To analyze if patients whose vestibular symptoms are associated with nonorganic sway patterns show more evidence of somatization and/or malingering than patients whose vestibular symptoms are associated with normal or physiologically abnormal sway patterns observed in people with documented vestibular pathologic findings., Patients: One hundred fifteen patients with complaints of vestibular dysfunction and hearing impairment., Interventions: Computerized dynamic posturography (CDP) and completion of the Modified Somatic Perception Questionnaire (MSPQ)--a validated test for the detection of malingering., Main Outcome Measures: Computerized dynamic posturography results classified into 4 categories (normal, physiologic abnormal, borderline-aphysiologic, and aphysiologic) were correlated with the results of the MSPQ., Results: A significant CDP group effect on the MSPQ, with the aphysiologic patients scoring significantly higher than the other groups. Moreover, a significantly higher proportion of aphysiologic patients scored more than the MSPQ cutoffs for malingering., Conclusion: Results indicate that patients who have aphysiologic CDP sway patterns are more likely to have higher MSPQ scores. Both aphysiologic CDP results and high MSPQ scores have been associated with intentional exaggeration. These results indicate that patients with both aphysiologic CDP findings and high MSPQ scores are more likely to be intentionally exaggerating their balance-related complaints and deficits.

The present study investigated whether speeded word generation performance patterns seen in healthy subjects are also produced in genuine and feigned traumatic brain injury (TBI). An expanded version of the Controlled Oral Word Association Test was administered to healthy controls, TBI patients, simulated malingerers, and probable clinical malingerers. Four performance patterns were operationalized. Three of these patterns were replicated in the healthy control sample and found to be unaltered by genuine TBI. They were then combined into a logistic regression model that discriminated well between examinees who put forth adequate effort and those who evidenced response bias.

Objective: To determine the value of pattern visual evoked potential (PVEP) testing with 5 consecutive check-size patterns in presumably malingering draftees., Design: Case-control study., Participants: The study group included 111 military conscripts (124 eyes) whose visual abnormalities could not be explained by the findings of ophthalmologic, neurological, and psychiatric examinations. The control group was comprised of 111 age- and gender-matched healthy subjects without ocular problems, except with refraction., Methods: The latency and amplitude of P100 for 5 consecutive patterns (2 degrees, 1 degrees, 30', 15', and 7') corresponding to visual acuities (VAs) of 0.1, 0.2, 0.4, 0.7, and 1.0, respectively, were measured in both groups. Pattern VEP-estimated VA (PVEP-VA) was determined by the VA corresponding to the smallest check size, with normal interocular variance in unilateral cases and normative data for P100 latency and amplitude values in bilateral cases. The best-performed VA was determined with a battery of clinical tests for malingering (VA obtained after simulation examination techniques [VA(aset)])., Main Outcome Measure: Comparison of PVEP-VA to VA(aset)., Results: In pure malingerers, PVEP-VA was 1.0 (normal recordings in all patterns) for all eyes (20 eyes), and all subjects were proven to be malingerers (true positives). Of the exaggerators, 81 (77.8%) with an underlying ophthalmic disorder had a +/-1-Snellen line discrepancy between PVEP-VA and VA(aset). Pattern VEP-estimated VA was well correlated with VA(aset) (r = 0.670). Sensitivity, specificity, and positive and negative predictive values of PVEP in functional visual loss were found to be 97.2%, 62.5%, 94.5%, and 76.9%, respectively., Conclusions: Pattern VEP testing with 5 consecutive check-size patterns may define VA objectively, especially in pure malingers; however, PVEP results should be evaluated in the context of the clinical examination, which remains the gold standard method to reveal the malingering.

This study examined patterns of grip strength when maximal and submaximal effort are applied. Using a sensor glove, 50 healthy subjects performed two different power grips. Both maximal and submaximal gripping showed characteristic patterns of strength distribution that were independent of the degree of power applied. Significant differences were also noted in the strength distribution patterns, depending on whether the grip was performed at maximal, or submaximal, strength. The small finger plays a decisive role in this. In maximal strength gripping, the total measured strength is distributed relatively evenly over all four fingers, with each finger contributing between 23% and 27% of the total strength. In submaximal strength gripping, the little finger is involved very little and only contributes between 14% and 15% of the total strength, with the remainder of the gripping distributed relatively evenly between the index, middle and ring fingers, each of which contributes between 26% and 32% of the total.

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.

Malingering is easy to define, difficult to detect, and very costly for any health care system. The structured interview of reported symptoms (SIRS) was constructed using rational strategies to detect malingering in patients endorsing psychotic symptoms. This study validated the SIRS using evoked potentials. Nineteen patients meeting DSM-IV criteria for schizophrenia and 15 healthy controls completed an oddball and paired click protocol. Severity of psychotic symptoms was documented using the Scale for the Assessment of Negative Symptoms and the Scale for the Assessment of Positive Symptoms. The patient group was divided by probability of malingering according to the SIRS. Patients with a high probability of malingering had significantly greater P3 amplitude (P = 0.006, t-test) and more P50 suppression (P = 0.044, t-test) than patients with a low probability of malingering. No significant difference in P3 amplitude or P50 suppression was found between the patients with a high probability of malingering and the healthy controls. This study provides empirical support for the validity of the SIRS with evidence that is independent of patient report.

The aim of this work was to draw attention to potentially life-threatening symptoms associated with Tourette syndrome (TS) and to explore their relationship to TS comorbidities. Medical records of all patients with TS evaluated at our Movement Disorders Clinic between July 2003 and July 2006 were reviewed. Data on patients with malignant TS, defined as >or=2 emergency room (ER) visits or >or=1 hospitalizations for TS symptoms or its associated behavioral comorbidities, were entered into a dataset and analyzed. Five illustrative cases are described. Of 333 TS patients evaluated during the 3-year period, 17 (5.1%) met the criteria for malignant TS. Hospital admission or ER visits were for tic-related injuries, self-injurious behavior (SIB), uncontrollable violence and temper, and suicidal ideation/attempts. Compared with patients with nonmalignant TS, those with malignant TS were significantly more likely to have a personal history of obsessive compulsive behavior/disorder (OCB/OCD), complex phonic tics, coprolalia, copropraxia, SIB, mood disorder, suicidal ideation, and poor response to medications. Although TS is rarely a disabling disorder, about 5% of patients referred to a specialty clinic have life-threatening symptoms. Malignant TS is associated with greater severity of motor symptoms and the presence of >or=2 behavioral comorbidities. OCD/OCB in particular may play a central role in malignant TS; obsessive compulsive qualities were associated with life-threatening tics, SIB, and suicidal ideation. Malignant TS is more refractory to medical treatment than nonmalignant TS., ((c) 2007 Movement Disorder Society.)

Forensic neuropsychology studies usually address either cognitive effort or psychological response validity. Whether these are distinct constructs is unclear. In 122 participants evaluated in a compensation-seeking context, the present Exploratory Factor Analysis examined whether forced-choice cognitive effort measures (Victoria Symptom Validity Test, Test of Memory Malingering, Letter Memory Test) and Minnesota Multiphasic Personality Inventory, Second Edition (MMPI-2) validity scales (L, F, K, FBS, Fp, RBS, Md, Dsr2, S) load on independent factors. Regardless of factor rotation strategy (orthogonal or oblique), four response validity factors emerged by means of both Principal Components Analysis (82.7% total variance) and Principal-Axis Factor Analysis (74.1% total variance). The four factors were designated as follows: Factor I, with large loadings from L, K, and S--underreporting of psychological symptoms; Factor II, with large loadings from FBS, RBS, and Md-overreporting of neurotic symptoms; Factor III, with large loadings from VSVT, TOMM, and LMT--insufficient cognitive effort; and Factor IV, with the largest loadings from F, Fp, and Dsr2--overreporting of psychotic/rarely endorsed symptoms. Results reflect the heterogeneity of response validity in forensic samples referred for neuropsychological evaluation. Administration of both cognitive effort measures and psychological validity scales is imperative to accurate forensic neuropsychological assessment.

The identification of insufficient effort is critical to neuropsychological evaluation, and several existing instruments assess effort on neuropsychological tasks. Yet instruments designed to detect insufficient effort are underutilized in standard neuropsychological assessments, perhaps in part because they typically require significant administration time and are, therefore, not ideally suited to screening contexts. The Test of Memory Malingering (TOMM) is a commonly administered, well-validated symptom validity test. This study evaluates the utility of TOMM Trial 1 as a relatively brief screening measure of insufficient effort. Results suggest that TOMM Trial 1 demonstrates high diagnostic accuracy and is a viable option for screening insufficient effort. Diagnostic accuracy estimates are presented for a range of base rates. The need for more comprehensive SVT assessment in most clinical and forensic situation is discussed.

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.