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The assessment of malingering has predominantly been considered within the domains of neuropsychologists and psychiatrists, who use consistency of performance criteria similar to those used in functional capacity evaluations (FCE). The use of activity has traditionally been used in occupational therapy as an assessment and treatment modality with goals not always considered obvious and which could easily be used for diversional reasons. The appropriate use of activity adds an additional dimension to a layered approach of using multiple data sources and methods as recommended by FCE practitioners and neuropsychologists alike. The case illustration aims to explain the above using a layered model.

The Test of Memory Malingering (TOMM) is a neuropsychological effort test in which scores below 45 on Trial 2 or Retention Trial indicate insufficient effort on testing, but Trial 1 score is not used. This study attempted to identify Trial 1 cut points above and below which further trials need not be administered. Data were analyzed from 114 patients referred for clinical neuropsychological evaluation. Sensitivity, specificity, and positive and negative predictive value for identifying failure on TOMM were calculated. Trial 1 scores > or =36 indicated 99% likelihood that TOMM would be passed; Trial 1 scores < or =27 indicated 100% likelihood of failure.

Exaggeration of cognitive symptoms or poor effort on cognitive testing has been addressed primarily in the traumatic brain injury literature. The present investigation aims to extend the evaluation of effort to the epilepsy monitoring setting, where base rates of failure on effort testing remain unknown for patients with intractable epilepsy (ES), psychogenic nonepileptic seizures (PNES), or both conditions (ES+PNES). In addition, this investigation explores how well four measures of effort (DMT, LMT, TOMM, PDRT) distinguish between these diagnostic groups. Results show that 20% of the combined sample failed one or more effort measure. When examining failure rates for each diagnostic group, 22% of epilepsy patients, 24% of PNES patients, and 11% of ES+PNES patients performed suboptimally on one or more measure of effort. The utility of these effort measures to differentiate between these diagnostic groups appears limited. Further research is needed to clarify the base rate of poor effort in the epilepsy monitoring unit setting in general and in these three diagnostic groups specifically.

Recent years have witnessed an explosion in the amount of research literature dedicated to the identification of symptom exaggeration and/or malingering in neuropsychological assessments. Additionally, there is now a growing literature devoted to estimating the base rates of symptom exaggeration/malingering in a range of populations and settings. However, very little literature has been devoted to estimating the positive predictive value (PPV) or negative predictive value (NPV) of these assessment devices and/or strategies. The current project was conducted to provide an illustrative example of how to use the research literature to calculate both PPV and NPV in everyday clinical practice. When the Word Memory Test (WMT) was used as the "gold standard" to which the Test of Memory Malingering (TOMM) was compared, the TOMM achieved very high PPV (.98) and acceptable NPV (.78). How to incorporate the strategy used into clinical practice is discussed.

The letter memory test (LMT) is a computerized forced-choice test of malingering detection including two face valid difficulty manipulations: increase in target stimulus length and increase of response foils. Prior research suggests the LMT shows promise as a malingering detection measure. In the present study, the utility of the LMT in the identification of malingering was further explored, using a counterbalanced design in a simulated malingering sample. Prior work was extended by assessing the robustness of the LMT to coaching and assessing the effectiveness of an additional scoring method, utilizing the face valid difficulty manipulations. Results were consistent with prior research on the LMT, with the standard cutoff score yielding high indices of accuracy. The LMT showed no order effects and was superior to the 15-item test in accuracy indices. Both the standard LMT score and the proposed score based on difficulty manipulations were relatively robust to coaching. Overall, findings indicate the LMT is a viable contender among measures of memory malingering.

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.

The current study examined if a newly developed series of reaction time tests, the Computerized Tests of Information Processing (CTIP), were sensitive to simulation of attention deficits commonly caused by traumatic brain injury (TBI). The CTIP consists of three reaction time tests: Simple RT, Choice RT, and Semantic Search RT. These tests were administered to four groups: Control, Simulator, Mild TBI, and Severe TBI. Individuals attempting to simulate attention deficits produced longer reaction time scores, made more incorrect responses, and exhibited greater variability than cognitively-intact individuals and those with TBI. Sensitivity and specificity values were comparable or exceeded those obtained on the Test of Memory Malingering. As such, the CTIP offers considerable promise of serving as a viable malingering test that uses a distinctively different paradigm than the two-item, forced-choice procedure employed by traditional symptom validity tests.

This study compared performance on the Test of Memory Malingering (TOMM [Tombaugh, T. N. (1996). Test of Memory Malingering (TOMM). New York: Multi Health Systems]) between a Forensic Psychiatric group and a Non-forensic Psychiatric group of 20 men each. It was hypothesized that the Forensic group would perform less well on the TOMM due to greater secondary gain for that population. The Forensic group (age, M=32.65 years; 16/20 were minorities) was composed of inpatients from a forensic psychiatric facility who had been referred for pre-trial evaluations. The Psychiatric group (age, M=41.00 years; 15/20 were Caucasian) were chosen from an inpatient psychiatric facility and had no pending legal involvement. As hypothesized, the Psychiatric group performed significantly better than the Forensic group on all TOMM trials. A TOMM score of below 45 on Trial 2 or the Retention Trial is consistent with probable response bias. Only one member of the Psychiatric group (the same individual) met this criterion, whereas seven members of the Forensic group met this criterion. The TOMM identified patients with pending legal charges as more likely to exert less effort than those with no obvious secondary gain.

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.

Fifty subjects with mild head injury involved in personal injury litigation and 2 subjects referred for evaluation of their disability status underwent comprehensive neuropsychological examination including the Test of Variables of Attention (TOVA). Group status was determined by performance on symptom validity testing. Twenty-six subjects who failed symptom validity testing formed the probable malingering (PM) group, while 26 subjects who passed symptom validity testing comprised the not malingering (NM) group. Subjects in the PM group performed significantly worse on all TOVA variables relative to subjects in the NM group. Discriminant function analyses revealed that TOVA omission errors >/=3 errors was the best predictor of group status. Malingering research employing a group of probable clinical malingerers has direct generalizability to real-world settings.

Past studies indicate that patients with incentive to fake neuropsychological symptoms are likely to have lower finger tapping scores than credible patients. The present study builds upon past research by investigating finger tapping performance for seven groups: (a) noncredible patients (as determined by failed psychometric and behavioral criteria), and patients with (b) closed head injury, (c) dementia, (d) mental retardation, (e) psychosis, or (f) depression, and (g) healthy older controls. Results showed that men tapped faster than women, requiring that groups be divided by gender. Noncredible male and female patients tapped slower than their comparison group counterparts. Dominant hand score proved to be more sensitive to noncredible performance than other scores (nondominant, sum of both hands, difference between dominant and nondominant), especially for women. Sensitivity, specificity, and positive and negative predictive value tables are presented. With specificity set at 90% for the comparison groups combined, a dominant hand cutoff score of

This investigation explored the usefulness of serial position patterns during word recall on the Rey Auditory Verbal Learning Test (RAVLT; Rey, 1964) as an indicator of poor effort. Significantly better recall for early (primacy) and recent (recency) material defines the serial position effect (SPE; Rundus, 1971). The SPE on the RAVLT was examined in four groups: normal controls (NC), symptom-coached simulators (SC), test-coached simulators (TC), and a group of moderate to severe subacute traumatic brain injury (TBI) patients. Normal control participants and TBI patients demonstrated the expected SPE. Only the SC simulators clearly suppressed the primacy effect. The SPE appears neither sensitive nor specific enough to be used independently of more sensitive symptom validity tests in the detection of suboptimal effort. It may be especially problematic when used with clients presenting with sophisticated styles of exaggeration and in settings with lower base rates of compromised effort.

Two studies were conducted to evaluate potential malingering indexes on the Halstead Category Test. The aim of the first study was that of documenting that groups of individuals with established cognitive impairment did not score positively on the proposed indexes. Of the indexes considered, it was found that these groups made very few errors on subtests I and II of the test and improved their performance on subtest VI relative to V. Subtests I and II are very simple and both subtest V and VI involve the same principle. It was proposed that malingerers would make excessive numbers of errors on subtests I and II, and would not show improvement on subtest VI over subtest V. The second study compared the performance of patients with brain damage to students who were either trained to malinger or encouraged to perform as well as they could on the Category Test. Comparisons were made on the malingering indexes among these groups showing that mean scores of the patients with brain damage on several of the indexes did not differ from those of the students encouraged to do well, but both of these groups did significantly better than the student malingerers. A discriminant analysis of the set of malingering indexes classified 20% of the student malingerers as brain damaged, and 3.4% of the patients with brain damage as malingerers. A stepwise analysis indicated that number of errors on subtests I and II and Total Errors were particularly sensitive to malingering.

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.

Cut-off scores defining clinically atypical patterns of performance were identified for five standard neuropsychological and psychological tests: Benton Visual Form Discrimination (VFD), Fingertapping (FT), WAIS-R Reliable Digit Span (RDS), Wisconsin Card Sorting Failure-to-Maintain Set (FMS), and the Lees-Haley Fake Bad Scale (FBS) from the MMPI-2. All possible pair-wise combinations of scores beyond cut-off (e.g., for VFD and FT; for RDS and FBS), correctly identified 21 of 24 subjects (87.5%) meeting criteria for definite malingered neurocognitive dysfunction, and 24 of 27 (88.9%) subjects with moderate to severe closed head injury. On cross-validation, 15 of 17 subjects (88.2%) meeting criteria for probable malingered neurocognitive dysfunction were correctly identified, with 13 of 13 nonlitigating neurologic patients, and 14 of 14 nonlitigating psychiatric patients correctly classified as having motivationally-preserved performance. Combining the derivation and cross-validation samples yielded a sensitivity of 87.8%, specificity of 94.4%, and combined hit rate of 91.6%.

A patient describing himself as totally color blind was ordered by the judicial system to have his color vision investigated in order to establish his suitability for military service. Basic clinical (Farnsworth Panel D-15, Moreland and Rayleigh anomaloscope equations), electroretinographic (ERG) and psychophysical techniques (spectral sensitivities) were applied to determine the extent of his color discrimination performance and cone function. These standard procedures were complemented by a test for cone interaction (transient tritanopia) and by newly developed cone-isolating flicker large-field ERG recordings. The patient's data consistently indicate the function as well as the functional interaction of the middle-wavelength-sensitive (M-) and the short-wavelength-sensitive (S-) cones. But the function of the long-wavelength-sensitive (L-) cones was completely absent. Hence the patient was correctly demonstrated to be a protanope. This study establishes that standard classical procedures, in combination with newly developed and easy to apply psychophysical and ERG ones, which can be reliably used to assess true color discrimination performance, in difficult cases of malingering.

Twenty-two undergraduate students completed a recognition memory test while event-related potentials (ERPs) were recorded. During the testing phase, subjects distinguished old from new words in a forced-choice format. There were two counterbalanced within-subject conditions, one in which subjects performed to the best of their abilities, and another with instructions to feign memory impairment. Test scores and response latencies differed significantly between the two conditions. Analysis of PCA-defined epochs revealed that old words were more positive than new in the control condition, with this difference confined to frontal regions and interpreted as reflecting familiarity-based recognition judgements. In the malingering task, this old/new word difference emerged earlier and was broadly distributed across the scalp. A discriminant function analysis using reaction time and ERP measures resulted in 82% correct classification of honest and simulated performance, with 79% correct on cross-validation.

The presence of physical symptoms that do not correlate with a disease process are often frustrating to healthcare professionals, are difficult to diagnose and may consume an inordinate proportion of healthcare resources. However, proper and complete physical and psychological assessment and treatment is becoming increasingly possible and essential. Physical illness may occur concomitantly and sometimes as a result of psychological distress, which has displayed itself in a diagnosed mental illness. In other cases physical symptoms may be caused by unconscious dynamics, and the process becomes the primary presenting mental concern. In other cases the physical illness is part of a conscious process and motivated by the hope of gain. Differentiation between physical symptoms of unconscious and conscious origin is important in selecting the correct response. A manager must first of all be alert for physical symptoms that appear to be consciously motivated, as in a disorder called "malingering." The essential feature of malingering is the intentional production of false or grossly exaggerated physical or psychological symptoms, motivated by external incentives such as avoiding work or obtaining financial compensation. Managers may inadvertently encourage malingering in the workplace by inappropriate responses to employees who present a physical complaint that is consciously motivated for gain. When the manager can recognize this phenomenon as malingering, appropriate managerial intervention can cause this behavior to be controlled and even eliminated and thus enhance productivity.

Purpose: To verify the efficiency and objectivity of the pattern visual evoked potential (VEP) for organic disorders of the cortical visual system., Methods: This retrospective study evaluated VEP in 19 patients diagnosed with psychogenic visual disturbance, 7 patients with malingering, and 37 age-matched normal volunteers. Transient (3 reversals per second) and steady-state (12 reversals per second) pattern VEPs for check sizes 15' and 30', with a contrast of 80%, were recorded., Results: The amplitudes of both transient and steady-state pattern VEPs were significantly increased in patients with psychogenic visual disturbance, while patients with malingering had significantly lower amplitudes. P100 peak latency was prolonged in both groups of patients., Conclusion: Monitoring of patients' fixation on the stimulus showed those with psychogenic visual disturbance fixated well on the stimulus, while those with malingering did not. This finding produced a VEP amplitude reduction in patients with malingering. The reason for the VEP amplitude in patients with psychogenic visual disturbance is unclear.

Twenty-four undergraduate university students with no known neurological disorders completed the Recognition Memory Test (Warrington, A., 1984. Recognition Memory Test manual. Windsor, Berkshire: NFER-Nelson.) while event-related potentials (ERPs) were recorded. Twelve subjects were instructed to feign a recognition memory deficit (malingering group), while the remainder served as controls. The malingerers performed poorly on the test compared to the control group. The 'old/new effect', an ERP measure thought to reflect recognition memory processes, did not differ between the groups, indicating recognition of previously learned material in the malingering group despite poor test performance. The study also revealed a second, early, old/new effect, maximal at left frontal sites in the malingering relative to the control group, suggesting task-related processing differences between the two groups. These effects appear to be of potential value in the detection of malingering of cognitive impairment in the clinical situation.

Dystonia in the causalgia-dystonia syndrome is characterized by a fixed dystonic posture. To identify involvement of central pathophysiologic mechanisms, we analyzed soleus H-reflex tests in five patients with causalgia-dystonia. Soleus H-reflex test results in these patients differed from those in healthy controls but were similar to those in purely dystonic patients and healthy controls mimicking dystonic posture. The results suggest involvement of supraspinal mechanisms in the abnormal posture of causalgia-dystonia.

Background: In patients where reliable subjective assessment of visual acuity is impossible, further diagnostics should be enhanced by an objective method., Patients and Methods: A group of 34 patients was examined by objective assessment of visual acuity using visual evoked potentials (VEP) as described by Hajek and Zrenner in 1988. The presentation of five checkerboards with different spatial frequency in repetitive sequences on a TV-monitor elicits a series of transient visual evoked potentials. Shape and amplitude of each wavelet depends on check size and directly reflect a spatial tuning function with a low- and high-frequency cut-off. This amplitude is described by a polynomial fit (2nd order). The function's intersection with the x-axis at higher spatial frequencies leads to an estimation of the visual acuity., Result: This result is compared to the subjectively determined visual acuity. In the majority of the presented cases the suspected malingering was confirmed., Conclusion: Patients with suspected malingering represent the primary indication of the described method.

The purpose of this study was to investigate the validity of the coefficient of variation as an identifier of feigned grip effort. Seventeen healthy female aged 20 to 25 yr participated in the study. Maximal and feigned efforts were measured isometrically and isokinetically (concentric and eccentric) using the Jamar and KinCom dynamometers, respectively. Findings indicated that, in all situations, the coefficient of variation derived from the maximal effort was significantly (P < 0.0001) lower than that derived from the feigned effort. However, the extent of overlapping between the two was sufficiently large to render the test sensitivities very low. Consequently, regardless of the measurement method, the coefficient of variation is not a valid tool for identifying feigned grip effort in healthy subjects.

The objective of this study was to develop an experimental method to separate a "faked" strength effort from a "best" effort in volunteers. Thirty-four pain-free volunteers (18 males, 16 females) performed a shoulder press and pull-down on an isokinetic computerized exercise testing system (CETS), giving a best effort followed by a faked effort. Two months later, a randomly selected subgroup (6 males) repeated the experiment to test the predictive validity of the derived variables. In the statistical analysis, best efforts were first compared with fake efforts by paired ttest for 80 CETS variables for males and females separately. Variables showing a strong difference between the best and faked effort were then selected for further analysis. In the second step of the analysis, the method of multiple correlations (r2 method) was used to reduce the number of redundant CETS variables to five in both the male and female groups. In the third step, a stepwise discriminant analysis was used to select predictor variables for the male and female groups. For the variables selected by the discriminant analysis for both males and females, sensitivities and specificities were calculated. Finally, the developed discriminant formula was used in the predictive validity part of the study to determine the sensitivities and specificities of the developed method. The discriminant analysis selected the following CETS variables for male and female groups, respectively: duty cycle down, work weight/down, peak value up (males); and average power up, 40% repetition down, duty cycle up (females). For males, using their three variables, the discriminant function classified 77.14% of the efforts correctly with 88.9% sensitivity and 64.7% specificity. For females, using their three variables, the discriminant function classified 90.63% of the efforts correctly with 100% sensitivity and 81.3% specificity. In the predictive validity group, the discriminant function classified 75% of the efforts correctly with 83.3% sensitivity and 66.7% specificity. This pilot study indicates that the method developed here may be useful in the experimental study for the discrimination between faked and best efforts on this isokinetic CETS machine. Future studies using this method will need to involve a larger number of volunteers.

Earlier research has supported the use of a P300 (P3)-based procedure to detect simulated amnesia. In the present experiment, an attempt was made to model the behavior and event-related potentials (ERPs) that amnestic patients might demonstrate with relatively easy recognition memory tests, by increasing the difficulty of a match-to-sample recognition memory test taken by 18 memory-unimpaired undergraduates. None of the participants in the modeled amnesic condition were classified as having intact recognition memory as the result of P3-based intra-individual tests (specificity = 100%). The results support the utility of a P3 procedure for the detection of malingering by demonstrating the procedure to be a valid measure of impaired recognition with this model of amnesia.

Fifty subjects with a history of traumatic brain injury (TBI) and/or substance use, completed neuropsychological measures of short and long term verbal and visual memory, information processing, motor speed and co-ordination, executive functioning, and malingering. All subjects performed below norms on tests of verbal memory and verbal abstract thinking, but overall no differences were found due to either severity of TBI or level of substance use. Maori subjects obtained the lowest scores on tests of verbal ability, but also reported higher rates of TBI and substance use, which is presumed to account for this result. In conclusion, prison populations seem to have disproportionately high rates of TBI, recurrent TBI, and substance use, compared to the general population. Further, there are a group of individuals who have experienced both TBI and substance abuse, with associated impairments in verbal memory and learning, abstract thinking, and who report problems with general memory and socialization. These difficulties may affect functioning both in prison and following release.

Two experiments using a P300-enhanced Forced Choice Procedure (P3FCP) investigated simulated amnesia in a matching-to-sample task. In Experiment 1, successful manipulation of subjects towards different behavioral hit rates (75-80% vs. 85-90%) did not adversely affect the diagnostic sensitivity of match-mismatch Pz-P300 amplitude analyses, allowing detection of 69% of simulators. P300 amplitudes of simulators (Malinger group) were as large as those of truth-tellers (truth group, a control), indicating no dual task-related (Malingering) reduction across different behavioral hit rates. Experiment 2 found no main effect of oddball type, match vs. mismatch, on P300 (P3) amplitude with a mismatch-rare variant of the P3FCP. This study also revealed larger Pz-P3s in the Malingering (vs. Truth-telling) condition. Subsequent topographic analyses suggested different Truth and Malinger scaled P3 amplitude topographies in both these sets of P3FCP data and in those from a previous autobiographical memory paradigm. Further analysis yielded preliminary evidence for a common deception-related P3 amplitude topography across different paradigms/conditions.

Purpose: Hysterical and malingering patients can manifest visual field defects on perimetry (visual field testing), including defects suggestive of true visual pathway pathology. It has been shown that control subjects can easily imitate some pathologic defects with automated, computed perimetry. The authors sought to determine whether subjects could imitate the same pathologic defect with manual and automated perimetry., Method: Six subjects posed as patients with neurologic problems. They had manual perimetry with both an experienced and inexperienced technician followed by automated perimetry. They were later interviewed about the methods of the technicians and the difficulty of the exercise., Results: Four of six subjects easily imitated the assigned defects with both technicians on manual perimetry and with automated perimetry. These included quadrantic, altitudinal, hemianopic, and enlarged blind-spot defects. Two subjects who were assigned cecocentral and paracentral scotomas instead produced enlarged blind spots by manual perimetry and defects suggestive of chiasmal pathology by automated perimetry. Paradoxically, some subjects found that experienced technicians were easier to fool than inexperienced technicians because of the systematic way in which experienced technicians defined defects., Conclusions: With minimal coaching, some subjects can imitate visual fields with enlarged blind spots, quadrantic, hemianopic, and altitudinal defects with ease and reproducibility by both automated and manual perimetry. Cecocentral and paracentral scotomas are harder to imitate but may be mistaken as representing chiasmal pathology. Paradoxically, experienced technicians may not be better at detecting hysterical or malingering individuals.

Data are submitted on patients with vibration disease, showing a disposition to malingering in this particular patient population, which fact necessitates its recognition in settling questions related to expert evaluation of the work fitness. Recommendations are offered on approaches to avoiding expert errors.

Sensory threshold measurements are criticized as subjective and therefore not to be relied upon in clinical diagnostic practice, particularly when deliberate deception by the patient is suspected. In an attempt to devise a method which permits dependable sensory threshold interpretation, individual variability of thresholds was examined in normal and neuropathic subjects. Normals were also instructed to feign sensory impairment resulting from hypothetical injury. For each subject, a number of threshold readings were averaged, yielding individual means and variances. Feigning normal subjects evidenced a larger variance compared to trustworthy normal and neuropathic subjects. Thus, alertness to variance reinforces the psychophysical analysis: small variance values suggest trustworthy normal or pathological results, whereas large variance calls the interpreter's attention to feigned results or inattentive test performance.

Thirty patients were referred to our visual evoked potential laboratory with complaints of profound acuity loss in one or both eyes. However, the objective ophthalmologic findings were normal, including pupillary reaction, and anterior segment and fundus examinations. Transient visual evoked potentials to a 2.3-c/deg sinusoidal grating pattern were found to be present in 26 of these 30 patients. Visual evoked potentials may be used as a measure of afferent pathway integrity.

Severe hypertension frequently requires hospitalization. Although hospital admission is undesirable for most patients, others are motivated to achieve hospitalization status for secondary gain. The authors present a case of a prison inmate who simulated severe hypertension with a combination of Valsalva's maneuver and arm flexion, on the background of preexisting essential hypertension and mitral valve prolapse. His secondary intent--to avoid his prison duties--classifies him as a malingerer. The differences between this malingering and the psychiatric diagnosis of Munchausen syndrome are discussed. The contributions of essential hypertension and mitral valve prolapse to the self-induced blood pressure elevations also are considered.

Five patients who presented with stimulus-induced jerking as part of an apparent myoclonic or pathological startle syndrome are reported. Neurophysiological observations in these patients suggested the jerks were voluntary in origin. These included (a) variable latencies to the onset of stimulus induced jerks, (b) latencies were greater than that seen in reflex myoclonus of cortical or brainstem origin, and were (c) longer than the fastest voluntary reaction times of normal subjects, (d) variable patterns of muscle recruitment within each jerk and, (e) significant habituation with repeated stimulation. It is argued that these features are consistent with a voluntary origin for the jerks and enable them to be distinguished from the stereotyped electrophysiological characteristics of myoclonus of cortical and brainstem origin. Electrophysiological recordings may help identify patients with this form of psychogenic movement disorder.

The development of the first standardized "scratch 'n sniff" olfactory test is described. Over 1600 subjects participated in five experiments. In Experiment 1, 50 microencapsulated odorants were rated as to their intensity, pleasantness, irritation, coolness, and familiarity, and two procedures for releasing them were compared. In Experiment 2, the results of the first experiment and other data were used in the development of the test, which was administered to a large number of subjects. Using multiple regression analysis, scores on this test were shown to be significantly related to the subjects' gender, ethnic background, and smoking behavior. Average test scores decreased as a function of age, with the greatest decline occurring between the sixth and tenth decades of life. These age-related changes were not correlated with scores on the Wechsler Memory Scale. Women performed better than men within all age categories. In Experiment 3, the test was shown to differentiate between subjects with known olfactory disorders (e.g., Kallmann's syndrome; Korsakoff's syndrome) and normal controls, and to reliably detect persons instructed to feign total anosmia. In Experiment 4, the test-retest reliability was established (6-month interval; r = 0.918, p less than 0.001), and in Experiment 5 the test was shown to correlate thresholds with odor detection (r = -0.794, p less than 0.001). This self-administratered test now makes it possible to rapidly and accurately assess general olfactory function in the laboratory, clinic, or through the mail without complex equipment or space-consuming stores of chemicals.