A comparison of four tests of malingering and the effects of coaching.

This study examined the ability of four measures of suboptimal performance to correctly classify four groups of subjects (normal controls, uncoached malingering, coached malingering, and head injured). Only the Portland Digit Recognition Test-Computerized (PDRT-C) identified simulating malingerers with greater than chance accuracy while minimizing false positives. Coached subjects were better able than their uncoached counterparts to avoid detection on all measures. In an additional analysis, a discriminant function using the response latency and total correct scores from the PDRT-C identified 70% of the coached malingerers on cross validation. The three other tests (Nonverbal Forced Choice Test, 21-Item Test, and Dot Counting Test) failed to obtain a satisfactory classification rate for the malingering groups as a whole and coached malingerers in particular.     

Detecting neuropsychological malingering: effects of coaching and information.

Concerns that patients presenting for neuropsychological assessment may not be putting forth maximum effort during testing has prompted the development of measures designed to detect malingering and incomplete effort. Two of these measures are the Computerized Assessment of Response Bias-97 (CARB-97) and Word Memory Test (WMT). Despite widespread use of these instruments, no study has been published determining the vulnerability of neuropsychological malingering measures to explicit coaching or brain injury information. The present study, using analog participants, found that the CARB-97 and WMT differentiate "normal" from "malingered" instructional sets, and show little difference between nai;ve and coached malingering efforts. There was also little difference between providing brain injury information and a no-information condition, but when effects were present, the information group generally scored worse. Further, it was found that response times (RTs), in addition to items correct, may also be effective in detecting those who are not giving their full effort.     

Malingering on neuropsychological memory tests: Potential objective indicators

We evaluated five potential indicators of malingering on the Rey Memory Test (RMT), Hebb's Recurring Digits (HRD), the Wechsler Memory Scale Revised (WMS-R). the Complex Figure Test (CFT), and the Auditory Verbal Learning Test (AVLT). Fifty-seven subjects were assigned randomly to either a control group or a simulated malingering group. Two indicators - discriminant functions derived from the WMS-R and from the CFT/AVLT achieved classification accuracy of 88% and 86%, respectively, without misidentifying controls as malingerers. Among the remaining indicators, there were problems with the recommended RMT cut-off, but it and the HRD show some promise. Subjects who simulated malingering did so by suppressing performance on tasks that involve recall as well as recognition memory and are relatively easy, but not obviously so.     

Detection of malingering in a Spanish population using three specific malingering tests.

The detection of feigned cognitive impairment remains difficult and may be even more challenging in certain population groups. Studies on the use of neuropsychological tests in ethnic groups for which they were not designed have shown variations in performance associated with cultural differences. With this background, our group studied a Spanish population by applying commonly used procedures [Victoria Symptom Validity Test (VSVT), Test of Memory Malingering (TOMM), and the b test] in a group with post-concussion syndrome (PCS) (whether litigants or not) and in a group of analog malingerers (AN). These tests appeared to function adequately in this Spanish population, who showed similar performances to results published for North Americans.     

A comparison of three neuropsychological tests: the Weigl, Hooper, and Benton

The accuracy of prediction of brain dysfunction for three neuropsychological tests-the Weigl, the Hooper, and the Benton-was compared. Sixty-six male, veteran, psychiatric inpatients were administered all three tests, and diagnoses of brain dysfunction or intactness were made by their ward psychiatrist, who used neurodiagnostic techniques. The results disclosed that each test alone can predict brain dysfunction significantly better than chance. All chi 2 tests were significant at the .025 level or better. When the Weigl was used as a moderator variable with the Hooper and also with the Benton, the p values for each test were somewhat reduced (p = .005 and .01), an indication of improvement in predictive power. When the percentage of predictive accuracy (hit rates) for the three tests used alone and in combination was analyzed, it was shown that the hit rate is increased by combining the Weigl with the Hooper and also with the Benton. It is increased further by combining all three tests into a predictive index.     

Cross-validation of a psychometric system for screening neuropsychological abnormality in older children

The Discriminant Equation (DE) represents a recently developed system for screening neuropsychological abnormality in older children. The DE was subjected to cross-validation on a sample of 82 child and adolescent psychiatric patients referred for a comprehensive neuropsychological assessment. An overall hit rate of 79.3% correct classification was found which supported the validity of the DE in predicting neuropsychological impairment. The findings are discussed in relation to population characteristics and the nature of the criterion to be predicted as they may affect the application of neuropsychological screening procedures.     

The subacute effects of CNS prophylaxis for acute lymphoblastic leukemia on neuropsychological performance: a comparison of four protocols.

We report an assessment of the intellectual functioning after one year of therapy of 117 children treated for acute lymphoblastic leukemia (ALL) who were assigned to one of four protocols for central nervous systems (CNS) prophylaxis. These protocols were (a) 2400 rad cranial irradiation plus concurrent intrathecal methotrexate (i.t. MTX), (b)i.t. MTX alone, (c) 1800 rad cranial irradiation plus concurrent i.t. MTX, and (d) a protocol for high-risk patients that included intensive systemic chemotherapy plus 2400 rad delayed irradiation. Neuropsychological evaluation consisted of the Wechsler intelligence scales, the Wide Range Achievement Test, and selected tests from the Halstead-Reitan Neuropsychological Battery administered one year after diagnosis. All patients performed in the average range on measures, although the high-risk patients performed marginally worse than did the others. In general, our results do not support previous reports that cranial irradiation results in early adverse neuropsychological sequelae.     

Level and variability of performance on neuropsychological tests.

Compared non-specific variability across subtests and overall level of performance on the Wechsler Adult Intelligence Scale (WAIS) and the Halstead-Reitan Battery (HRB) for normal, schizophrenic, acute and chronic brain-damaged Ss. Both variability and level of performance measures for each of the two test batteries significantly distinguished normal from abnormal Ss, but the HRB measures were more sensitive. Intra-S variability across subtests had a significant negative correlation with level of performance on the HRB, but not on the WAIS. This correlation could not be accounted for fully by a ceiling effect and was thought to represent in part a characteristic feature of ts performance on the HRB. While WAIS variability appeared to be independent of level of performance, it was not much help in differentiating between the four S groups. It was concluded that non-specific variability across subtests is not a helpful independent measure of neuropsychological function on the two batteries studied.     

Comparison of four erythrocyte fragility tests as indicators of vitamin E status in adult dogs.

Plasma alpha-tocopherol (alpha-T) concentrations, erythrocyte osmotic fragility and detergent sensitivity were measured at 8 week intervals in two 1-year-old male beagle dogs fed a vitamin E-deficient diet (< 0.08 mg per kg alpha-T) and in two control beagles fed the same diet supplemented with vitamin E (> 90 mg per kg alpha-T). Beginning at 24 weeks, dialuric acid haemolysis and spontaneous haemolysis were evaluated also. In the vitamin E-deficient dogs, plasma alpha-T concentrations declined progressively from baseline values of 20.5 and 31.3 micrograms per ml to 0.11 and 0.07 micrograms per ml, respectively, by 90 weeks. The supplemented dogs maintained alpha-T concentrations between 18.3 and 38.4 micrograms per ml. Both dialuric acid haemolysis (R = -0.89) and spontaneous haemolysis (R = -0.91) increased with declining plasma alpha-T concentration. In the dialuric acid haemolysis assay, 50 per cent haemolysis occurred when plasma alpha-T declined to 1.7 micrograms per ml, compared with spontaneous haemolysis in which 50 per cent haemolysis occurred when plasma alpha-T declined to 0.5 micrograms per ml. Osmotic fragility and detergent sensitivity remained unchanged in the vitamin E-deficient dogs throughout the study. Of the four tests, dialuric acid haemolysis was the most sensitive in-vitro assay for vitamin E deficiency in adult dogs.     

Detecting malingering: a survey of experts' practices.

A survey addressing practices of 'expert' neuropsychologists in handling financial compensation claim or personal injury litigation cases was carried out. Potential participants were identified by publication history. Responses were obtained from 24 out of the 39 neuropsychologists who were surveyed. Approximately 79% of the respondents reported using at least one specialized technique for detecting malingering in every litigant assessment. Half stated that they always give specialized tests at the beginning of the assessment. The Rey 15-Item test and the Test of Memory Malingering were the most frequently reported measures. Respondents also reported frequent use of 'malingering' indexes from standard neuropsychological tests. Reported base-rates varied, but the majority of respondents indicated that at least 10% of the litigants they assessed in the last year were definitely malingering. Respondents were split on the practice of routinely giving warnings at the outset of assessments that suboptimal performance may be detected. However, when the client's motivational status was suspect, more than half (58.3%) altered their assessment routine at least on some occasions, by encouraging good effort (70.8%) or administering additional SVTs. A minority directly confronted or warned clients (25%), terminated the examination earlier than planned (16.6%), or contacted the referring attorney immediately (29.2%). Respondents almost always stated some opinion regarding indicators of invalidity in written reports (95%). However, 41.7% rarely used the term 'malingering' and 12.5% never used the term. Most respondents (>80%) instead stated that the test results are invalid, inconsistent with the severity of the injury or indicative of exaggeration.     

The relationship between neuropsychological performance and daily functioning in individuals with Alzheimer's disease: ecological validity of neuropsychological tests.

The current study examined the relationship between neuropsychological test performance and functional status in 42 individuals diagnosed with Alzheimer's disease. A comprehensive battery of cognitive tests was employed in order to assess a wide range of neuropsychological abilities. Functional status was measured through the use of both a performance-based scale of activities of daily living (an expanded version of the Direct Assessment of Functional Status; DAFS, Loewenstein et al., 1989), and by a caregiver/informant-based rating scale (Instrumental Activities of Daily Living; IADL, Lawton & Brody, 1969). Findings suggest that neuropsychological functioning is moderately predictive of functional status. Using multiple regression analyses, neuropsychological variables accounted for 25% of the variance in the IADL and 50% of the variance in the DAFS. Individual domains of both functional measures were also significantly predicted by the neuropsychological variables. The findings provide evidence of a relationship between neuropsychological test performance and ADLs in an Alzheimer disease patient population.     

Effect of hippocampal lesions on rat shuttle responses in four different behavioral tests

Rats with lesions in subareas CA1 - CA2 of the dorsal hippocampus made more shuttle responses to a buzzer than sham-operated or intact control animals in four different shuttle-box situations using buzzers and footshocks as stimuli. These differences were much more marked in two of the tests, in which the buzzer-shock interval was varied at random (a pseudoconditioning situation and an avoidance paradigm without stimulus pairing), than in the other two tests, in which the stimuli were paired on all trials (a Pavlovian paradigm and a typical two-way avoidance situation). These data agree closely with those of a previous report on the effect of hippocampal spreading depression on the same four tests. The results suggest that the hippocampus plays a role both in the inhibition of nonassociative effects of the footshocks and in the establishment of stimulus-stimulus relations in the brain.     

Detecting change: A comparison of three neuropsychological methods, using normal and clinical samples.

Detecting change in individual patients is an important goal of neuropsychological testing. However, limited information is available about test-retest changes, and well-validated prediction methods are lacking. Using a large nonclinical subject group (N = 384), we recently investigated test-retest reliabilities and practice effects on the Wechsler Adult Intelligence Scale and Halstead-Reitan Battery. Data from this group also were used to develop models for predicting follow-up test scores and establish confidence intervals around them. In this article we review those findings, examine their generalizability to new nonclinical and clinical groups, and explore the sensitivity of the prediction models to real change. Despite similarities across samples in reliability coefficients and practice effects, limits to the generalizability of prediction methods were found. Also, when multiple test measures were considered together, one or more "significant" changes were common in all (including stable) subject groups. By employing normative cut-offs that correct for this, sensitivity of the models to neurological recovery and deterioration was modest to good. More complex regression models were not more accurate than the simpler Reliable Change Index with correction for practice effects when confidence intervals for all methods were adjusted for variations in level of baseline test performance.     

Centromedian nucleus stimulation for epilepsy: Clinical,electroencephalographic, and behavioral observations

A series of 49 cases with difficult to control seizures and non-candidates for ablation of the epileptic focus has been treated with electrical stimulation of the centromedian thalamic nuclei (ESCM).Selected cases were: (1) epilepsia partialis continua (EPC) (n=5); (2) partial complex seizures (n=16); (3) bilateral frontal parasagittal seizures (n=6); (4) Lennox–Gastaut syndrome (n=22). All patients had four contact electrodes placed bilaterally through frontal parasagittal burr holes and guided by ventriculograms. Plotting of electrodes on sagittal and frontal sections of the Schaltenbrand and Bailey’s atlas permitted to determine their location. Electrodes were left externalized for periods of weeks to months to carry out the following tests. (1) Recordings of spontaneous seizures occurring during wakefulness and sleep. (2) Electrophysiological confirmation of their position by means of recruiting responses and desynchronization induced by low and high frequency stimulation. (3) Effects of high frequency stimulation on interictal and ictal activities. Electrodes were internalized and connected to a subcutaneous pulse generator programmed for alternating right and left ESCM 1 min ON and 4 min OFF at 60–130 Hz, 0.21–0.45 ms, 3–5 V forward and backward for 24 h per day. Repeated EEG recordings and a calendar of seizures were used for follow-up from 1 to 9 years.CM paroxysmal discharges followed the initiation of seizures in cortical areas, occurred simultaneously with spike wave (SKW) complexes in cortical areas in Lennox–Gastaut syndrome and preceded the initiation of cortical SKW and clinical seizures in typical absences. Low frequency stimulation (6–8 cps) induced recruiting responses that were associated with those electrodes that produced best seizure control. Good to excellent results were obtained in cases of EPC and Lennox–Gastaut syndrome and on generalized tonic clonic convulsions (GTCs) and atypical absences (AA) with tonic or clonic components.Consequently, we came to the conclusions that the CM participates in the propagation of most seizure types and also in the genesis of some of them and that ESCM is a safe and useful alternative for the treatment of some of the most difficult cases of uncontrollable seizures.     

Adolescent male bullies, victims, and bully-victims: a comparison of psychosocial and behavioral characteristics

OBJECTIVE: To determine among male adolescents whether bully-victims would report the poorest psychosocial health, the worst attitudes toward school, more problem behavior (delinquency, weapons possession, and substance use), and more physical injury compared with bullies, victims, and neutral students. We also assessed ethnic differences in bullying category membership. METHODS: Employing multisample latent variable models, we contrasted 1,312 males in grades 7-12 classified as bullies (n = 299), victims (n = 180), bully-victims (n = 195), and neutral (n = 638) on school attitudes, psychosocial health, problem behaviors, and physical injury. RESULTS: Hypotheses were generally confirmed, especially contrasts between bully-victims and neutrals. However, bullies did not have better school attitudes than bully-victims, and victims only marginally reported better psychological health than bully-victims. The boys of mixed ethnicity were more likely to be victims. CONCLUSIONS: Greater awareness of the problems associated with boys who both bully and are victimized is necessary for improved intervention.     

Double-stranded DNA antibodies: a comparison of four methods of detection.

Thirty-four antinuclear antibody (ANA) positive systemic lupus erythematosus (SLE) sera were tested for antibodies to double-stranded DNA (dsDNA) simultaneously using Farr, haemagglutination, Crithidia luciliae (CL) kinetoplast fluorescence and human metaphase chromosome fluorescence assays. Significant correlation (p less than 0 x 05) was found between the Farr and CL assays, with the two fluorescence tests (CL and metaphase) displaying the greatest degree of association (p = 0 x 00001). No correlation could be demonstrated between the haemagglutination test and any of the other three assays. Six hundred and ninety-one sera from patients with a range of provisional rheumatological diagnoses were prospectively analysed for dsDNA antibodies using Farr and metaphase assays. A correlation coefficient of 0 x 84 was obtained between the two assays. The metaphase assay provides comparable results to other more established assays, and because it is simple, reliable and sensitive, it should be seriously considered for routine use in testing for dsDNA antibodies.