Classification accuracy of multiple visual spatial measures in the detection of suspect effort

A wide variety of cognitive measures, particularly memory measures, have been studied for their ability to detect suspect effort, or biased responding on neuropsychological assessment instruments. However, visual spatial measures have received less attention. The purpose of this study was to evaluate the classification accuracy of several commonly used visual spatial measures, including the Judgment of Line Orientation Test, the Benton Facial Recognition Test, the Hooper Visual Organization Test, and the Rey Complex Figure Test-Copy and Recognition trials. Participants included 491 consecutive referrals who participated in a comprehensive neuropsychological assessment and met study criteria. Participants were divided into two groups identified as either unbiased responding (UR, N = 415) or biased responding (BR, N = 30) based on their performance on two measures of effort. The remaining participants (N = 46) had discrepant performance on the symptom validity measures and were excluded from further analysis. The groups differed significantly on all measures. Additionally, receiver operating characteristic (ROC) analysis indicated all of the measures had acceptable classification accuracy, but a measure combining scores from all of the measures had excellent classification accuracy. Results indicated that various cut-off scores on the measures could be used depending on the context of the evaluation. Suggested cut-off scores for the measures had sensitivity levels of approximately 32-46%, when specificity was at least 87%. When combined, the measures suggested cut-off scores had sensitivity increase to 57% while maintaining the same level of specificity (87%). The results were discussed in the context of research advocating the use of multiple measures of effort.     

Relationships between measures of auditory verbal learning and executive functioning

Abstract

Relationships between performance on the California Verbal Learning Test (CVLT) and executive abilities were examined. In a sample of 115 neurological cases principal components factor analysis produced five theoretically and clinically meaningful CVLT factors. The five CVLT factors reflected general verbal learning (CVLT1), response discrimination (CVLT2), a proactive interference effect or “working memory” (CVLT3), serial learning strategy (CVLT4), and a retroactive interference effect (CVLT5). Canonical correlation between executive function measures and the five CVLT factor scores yielded one significant canonical variable accounting for 29 percent of the variance in the data. Two CVLT factors (CVLT1 and CVLT3), the Trail Making Test Part B, and Digit Span were significantly correlated with the canonical variate. Higher levels of memory performance were associated with better attention and mental tracking. Based on the present findings, attentional aspects of executive abilities appear to play a role in learning and working memory. Other aspects of executive abilities (abstraction, problem-solving, planning) appear to have minimal relationships with memory processes.     

The utility of the Rey Word Recognition Test in the detection of suspect effort

The Rey Word Recognition Test potentially represents an underutilized tool for clinicians to use in the detection of suspect effort. The present study examined the predictive accuracy of the test by examining the performance of three groups of participants: (a) 92 noncredible patients (as determined by failed psychometric and behavioral criteria and external motive to feign), (b) 51 general clinical patients with no motive to feign, and (c) 31 learning disabled college students. Results demonstrated gender differences in performance that necessitated separate cutoff scores for men and women. Use of a cutoff score of < or = 7 words correctly recognized identified 80.5% of noncredible female patients while maintaining specificity of > 90%. However, to achieve this level of specificity in male noncredible patients, the cutoff score had to be lowered to < or = 5, with resultant sensitivity of only 62.7%. A combination variable (recognition correct minus false positive errors + number of words recognized from the first 8 words) showed enhanced sensitivity in identifying suspect effort in a subset of the noncredible sample who were claiming cognitive symptoms secondary to traumatic brain injury (i.e., cutoff score of < or = 9 = 81.6% sensitivity with 90% specificity). Results indicate that the Rey Word Recognition Test is an accurate and cost-effective method for the detection of noncredible cognitive performance.     

Sensitivity and specificity of various digit span scores in the detection of suspect effort

Digit Span Age-Corrected Scaled Score (ACSS) and Reliable Digit Span (RDS) have been suggested as effective in assessing credibility. The purpose of this study was to confirm the efficacy of suggested cutoffs for ACSS and RDS and to explore the utility of other Digit Span variables in a large sample (N = 66) of "real-world" > or = suspect effort patients versus clinic patients with no motive to feign (N = 56) and controls (N = 32). With specificity at > or = 90%, sensitivity of ACSS increased from 32% to 42% when a < or = 5 cutoff was used instead of the recommended < or = 4. The RDS recommended cutoff of < or = 7 resulted in a sensitivity of 62% but with an unacceptably high false positive rate (23%); dropping the cutoff to < or = 6 raised the specificity to 93% but sensitivity fell to 45%. Cutoffs for other Digit Span scores did not exceed 45% sensitivity with the exception of 50% sensitivity (11% false positive rate) for average time per digit for all attempted items > 1.0 second. A criterion of ACSS < or = 5 or RDS < or = 6 was associated with 51% sensitivity (91% specificity) while RDS < or = 6 or longest string with at least one item correct < or = 4 was associated with 54% sensitivity (88% specificity). While only moderately sensitive, Digit Span scores, including new time variables, may have a unique and effective role in the detection of suspect effort.     

Sensitivity and specificity of finger tapping test scores for the detection of suspect effort

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 相似文献   

Relationships between quantitative EEG measures and pharmacodynamics of alfentanil in dogs

Intravenous alfentanil was administered as a constant 1 h infusion to 6 dogs. Before, during and up to 3 h after infusion, the effects of 3 doses (0.001, 0.004 and 0.016 mg/kg/min) on 6 quantitative EEG measures (zero-crossing frequency, root mean square (rms) amplitude, spectral edge, relative delta, alpha and beta power) were assessed in relation to plasma concentrations of alfentanil. All EEG measures, except zero-crossing frequency and rms amplitude, showed statistically significant dose-dependent changes in peak effect and duration. In addition, times-to-peak effect and return-to-baseline were sensitive to dose. The EEG effects of the low dose were smaller than those of the middle and high doses, whose peak effects did not statistically differ; but the high dose produced more persistent effects, which outlasted the infusion period for a longer time. Alfentanil-induced changes in rms amplitude and relative delta power showed the widest dynamic ranges. Measurable EEG changes occurred at low plasma concentrations, but EEG responses saturated at the middle dose. Significant correlations between plasma concentration and EEG effect were obtained for only the subperiod ranging from onset of infusion to peak EEG effect, indicating very short concentration-effect equilibration delays. On the other hand, clockwise concentration-effect loops were suggestive of acute tolerance: EEG responses peaked before peak plasma levels and they returned to baseline at dose-dependently higher plasma concentrations of alfentanil.     

The vulnerability to coaching across measures of effort

Neuropsychologists are increasingly called upon to conduct evaluations with individuals involved in personal injury litigation. While the inclusion of measures of effort within a test battery may help clinicians determine whether a client has put forth full effort, attorney coaching may allow dishonest clients to circumvent these efforts. The purpose of this study was to determine the degree to which frequently used measures of effort are susceptible to coaching, as well as to explore and classify strategies undertaken by coached malingering simulators. Overall, coached simulators performed significantly better on 7 of 14 measured variables. Potential improvements in the external validity of the simulation design were also explored.     

Failure to inhibit the reading response on the Stroop Test: a pathognomonic indicator of suspect effort

We present 6 patients who displayed noncredible effort on neuropsychological testing (verified by failures on specialized measures designed to discreetly assess effort status and multiple behavioral inconsistencies) and complained of complete illiteracy secondary to impoverished educational history, learning disability, or acquired brain injury. The Stroop Test, a measure of a specific aspect of executive function requiring inhibition of an automatized oral reading response in favor of a less habitual, competing color-naming response, was administered to these patients. All six subjects claimed that they were unable to perform the Word-Reading trial as a consequence of total reading disability, but on the Color-Word Interference trial, they all committed "errors" by reading the written words. Five of the six subjects also performed substantially slower on the Interference condition relative to the Color-Naming trial, indicating that they were in fact inhibiting a reading response. However, in cases involving complaints of complete reading illiteracy, the observation of these individuals performing an act that they claimed to be unable to do was the most powerful and pathognomonic indicator of deliberate feigning or exaggeration of impairment in these cases.     

Re-examination of a Rey auditory verbal learning test/Rey complex figure discriminant function to detect suspect effort

Bernard (1990), and Bernard, Houston, and Natoli (1993) identified a discriminant function, derived from Rey figure recall score and RAVLT trial 1 and recognition, which discriminated simulators and controls with 77--85% accuracy. However, in the current study, application of the discriminant function to patients with suspect effort, brain injured patients, and controls, revealed excellent sensitivity (95%) but low specificity (33% for patients, 61% for controls). A new discriminant function using the same Rey figure and RAVLT scores, derived from actual patients with documented suspect effort and patients with confirmed brain injury, resulted in an overall classification of 85% correct, with only 16% of suspect effort and 15% of brain injured patients misidentified. Use of a discriminant function score of /=91%.     

Relationships between clinical symptom severity scales and nerve conduction measures in carpal tunnel syndrome

This study examined the severity of symptoms in carpal tunnel syndrome (CTS) in relation to nerve conduction measures of the median nerve. Clinical symptom severity and nerve conduction studies were evaluated for 64 hands with CTS in 45 patients. We found the following: (1) significant relationships identified among the clinical scales resulted in a dichotomous symptom classification scheme into primary and secondary symptoms, with the former being more specific for those symptoms usually seen in association with nerve injury; (2) there were significant relationships between symptom severity and nerve conduction abnormality; (3) the primary symptom scale correlated more strongly with the electrodiagnostic measures of nerve injury than did the secondary symptom scale. Based on these findings, we believe that these clinical scales have biological significance and reflect median nerve injury. This would support their potential utility for evaluating the outcome of CTS treatment and developing a model for exposure-severity relationship.     

Effectiveness of the Rey-Osterrieth Complex Figure Test and the Meyers and Meyers recognition trial in the detection of suspect effort

The Rey-Osterrieth Complex Figure Test (ROCFT) is a popular measure of visuoconstructive skills and visual memory. A recognition memory trial was recently developed by Meyers and Meyers (1995) and attached to the standard administration of the ROCFT. The addition of this recognition paradigm (comprised of 12 small designs from the original ROCFT stimulus interspersed among 12 foils) makes ROCFT a potentially useful instrument in capturing suspect effort because patients attempting to feign memory difficulties typically operate from the misconception that recognition memory is as impaired as free recall in brain injury and, as a result, suppress recognition performance. The ROCFT (copy, immediate recall [i.e., 3-min recall], and the recognition trial) was administered to four sets of participants: 58 patients with suspect effort; 23 neuropsychology clinic patients with verbal memory impairment, 17 clinic patients with visual memory impairment, and 30 clinic patients without memory impairment. Group comparisons revealed significant group differences in direct copy, immediate recall, and recognition scores of the ROCFT (p<.0001), with the suspect effort group displaying significantly lower performance on the copy and immediate recall scores than the verbal memory impaired and nonmemory impaired clinic patient groups, and significantly lower recognition scores than all three clinical groups. Furthermore, qualitative examination of the recognition trial revealed the presence of "atypical recognition errors" that were endorsed with significantly higher frequency by the suspect effort patients. A combination score incorporating the copy, true positive recognition, and atypical recognition error scores yielded a sensitivity of 74% while misclassifying only approximately 4% of verbal memory impaired clinic patients, 12% of visual memory impaired clinic patients, and 3% of nonmemory impaired clinic patients. Thus, the ROCFT+recognition trial show considerable potential for detecting noncredible effort.     

Relationships between quantitative measures and neurologist's clinical rating of tremor and standing steadiness in two epidemiological studies

OBJECTIVE: The purpose of the present investigation was to 1) compare a neurologist's physical examination (NPx) rating of severity of postural tremor to several summary measures derived from quantitative measurements of tremor and 2) compare a NPx rating of standing steadiness and related clinical findings to quantitative sway speed measurements. METHODS: Comparisons were performed on data obtained from two epidemiological field studies: 1) retired heavy industrial workers (n= 198, approximately half previously exposed to elemental mercury), and 2) small town residents (n=234, approximately 40% with environmental exposure to arsenic). A commercially available tremor measurement instrument was used in both studies. To obtain standing steadiness measures, a head position monitoring device was used in the mercury study, and a force platform was used in the arsenic study. The NPx included assessment of postural tremor, as well as evaluation of vibration perception and proprioception of the great toe, Achilles tendon reflex activity, Romberg test status, and tandem gait. One neurologist performed all the NPx in both studies and results were graded as normal, equivocal, or abnormal. The square root of the proportion of variance accounted for by a linear trend term in ANOVA models was used as an estimate of association between quantitative tests and clinical examination grade. An estimate of agreement, kappa, was also calculated after both NPx and quantitative test results were dichotomized. RESULTS: Most tremor summary measures varied monotonically with NPx tremor severity grade. Moderately good associations were observed between the tremor acceleration measure and NPx postural tremor grade (correlations up to approximately 0.5). Sway speed with eyes open and with eyes closed increased monotonically with NPx grade for most of the clinical signs. The NPx signs showing the strongest relationships with sway speed were Romberg test performance, tandem gait, and proprioception and vibration sensation of the great toe (correlations up to approximately 0.5). CONCLUSIONS: Quantitative tremor measurements were related to a neurologist's grading of postural tremor. Sway speed was associated with several NPx findings related to standing stability. Quantitative measurements of tremor and standing stability may provide more precise and objective measures of neurological function than NPx by a neurologist and are likely to be more consistent across times and examiners.     

Relationships between central and autonomic measures of arousal at age 15 years and criminality at age 24 years

Previous studies have indicated that criminality is in part genetically determined, but it is not clear how this predisposition manifests itself at a biological level. This prospective study tests the hypothesis that a psychophysiological predisposition to criminality partly manifests itself through autonomic and central nervous system underarousal. Psychophysiological measures, taken at the age of 15 years, were related to criminality status that was assessed at the age of 24 years. Criminals had a significantly lower resting heart rate, skin conductance activity, and more slow-frequency electroencephalographic activity than noncriminals. Differences were not mediated by social, demographic, and academic factors. These results constitute the first clear evidence that implicates underarousal in all three response systems (electrodermal, cardiovascular, and cortical) in the development of criminality. Although arousal variables correctly classified 74.7% of all subjects, psychophysiological factors alone cannot fully account for criminal behavior and do not negate the potential role of social variables in predicting criminal behavior.     

Performance of patients with epilepsy or psychogenic non-epileptic seizures on four measures of effort

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.     

Relationships between IQ and neuropsychological measures in neuropsychiatric populations: within-laboratory and cross-cultural replications using WAIS and WAIS-R

Several studies have reported positive correlations between measures of intelligence (a quasi-subject variable) and level of performance on neuropsychological tests; few, however, have presented test results by IQ grouping, which could be useful for comparative purposes. The present study examined the relationships of WAIS and WAIS-R Full Scale IQ to performance on a neuropsychological battery consisting of the Halstead-Reitan Battery (HRB), the Wide Range Achievement Test (WRAT), and the Wechsler Memory Scale (WMS). Four mixed neuropsychiatric samples provided cross-cultural and within-laboratory replications, two tested with WAIS and two with WAIS-R. Means and standard deviations for each measure were presented by five IQ levels within each sample. IQ was strongly related to scores on problem-solving tasks, auditory and linguistic measures, memory tasks, academic achievement levels, and tactual imperceptions, while motor functioning and sensory suppressions were less strongly related to IQ. IQ level was related to educational level in all samples. Correlations of years of education with dependent variables in the two WAIS-R samples were strong and replicable for WRAT scores, verbal memory measures, linguistic errors on the Aphasia Screening Test, and finger-tapping speeds but not for other HRB measures. Finally, IQ-HRB relationships were compared to those reported for other populations.     

Neuropeptide Y-like immunoreactivity in schizophrenia. Relationships with clinical measures

Neuropeptide Y-like immunoreactivity (NPY-li) was measured in CSF of 35 drug-free chronic schizophrenic patients. Compared to a group of drug-free controls, CSF NPY-li was significantly higher in these patients. CSF NPY-li decreased with age and longer duration of illness. Measures of structural brain abnormalities on CT scans were significantly associated with lower CSF NPY-li. Relationships between NPY-li and schizophrenic behavior, i.e. positive symptoms, were observed only in the clinically stable (nonrelapsed) drug-free patients. In 31 of the patients CSF was obtained before and after withdrawal from haloperidol maintenance treatment. This withdrawal from haloperidol treatment was associated with a significant increase in CSF NPY-li. There was no significant difference in CSF NPY-li between patients who did and those who did not relapse within 6 weeks following haloperidol withdrawal. The present findings suggest a relationship of CSF NPY-li with various aspects of schizophrenia.     

Changes in short-term measures of heart rate variability after eight weeks of cardiac rehabilitation

Background In coronary artery disease (CAD) and following myocardial infarction (MI), activity of the autonomic nervous system is altered. Reduced heart rate variability (HRV) is a risk factor for future cardiac event. Studies reporting changes in HRV post-cardiac rehabilitation (CR) are heterogeneous, due possibly to varied data collection and analysis protocols. Aim To evaluate changes in spectral measures of HRV derived from 5-minute ECG recordings in patients completing an 8 weeks CR programme. Methods Thirty-eight patients (21 males, 17 females, aged 65.6 ± 11.6 years) underwent 5 minutes, supine ECG recordings and standard physiological and psychological assessment pre- and post-CR. A further 23 patients (14 males, 9 females aged 64.9 ± 9 years) acted as controls. Outcome measures were: low frequency power, (LF, 0.04–0.15 Hz) high frequency power (HF, 0.15–0.40 Hz), LF:HF ratio and mean RR interval. Change was assessed by ANCOVA and paired t-tests. Results When compared with the CT group, the CR group showed significant increases in: SDNN (Δ +6 ms, CR vs. 0 ms CT), HFln (Δ 0.4 log units CR vs. 0 log units CT), LFln (Δ +0.6 log units CR, vs. +0.1 log units CT) and RR interval (Δ +30 ms, CR vs. −28 ms CT). Conclusions This is the first study to show significant increases in raw LF and HF power derived from short-term ECG recordings in CR patients. These measures are risk factors for future cardiac event. As CR is associated with increases in these measures it may be viewed as an effective therapy capable of bringing about favourable alterations in autonomic control.     

Sleep quality versus sleep quantity: Relationships between sleep and measures of health, well-being and sleepiness in college students

Two studies assessed whether measures of health, well-being, and sleepiness are better related to sleep quality or sleep quantity. In both studies, subjects completed a 7-day sleep log followed by a battery of surveys pertaining to health, well-being, and sleepiness. In subjects sleeping an average of 7 hours a night, average sleep quality was better related to health, affect balance, satisfaction with life, and feelings of tension, depression, anger, fatigue, and confusion than average sleep quantity. In addition, average sleep quality was better related to sleepiness than sleep quantity. These results indicate that health care professionals should focus on sleep quality in addition to sleep quantity in their efforts to understand the role of sleep in daily life.     

Relationships among subjective and objective measures of adherence to oral antipsychotic medications

OBJECTIVE: The most common ways of assessing adherence to oral antipsychotic medications in research and in clinical practice are self-report and physician report. This prospective study examined the agreement among measures of adherence to oral antipsychotic medications among 52 outpatients with schizophrenia. METHODS: Participants were assessed at baseline during a visit to their outpatient clinic and followed for 12 weeks. Adherence was assessed by using subjective measures (self-report and physician report) and objective measures (pill counts conducted in the home, electronic monitoring, and blood plasma concentrations). Electronic monitoring was used as an imperfect standard against which other methods were judged. RESULTS: Data from pill counts and from electronic monitoring were strongly correlated (r(k)=.61). Self-report and physicians' ratings of compliance were weakly correlated with pill count and electronic monitoring when compliance scores were examined with rank-order correlations (r(k)=.18-.32). When the sample was dichotomized into adherent and nonadherent groups on the basis of electronic monitoring or pill count (at least 80% adherent), neither physicians nor patients identified adherent behavior (kappa相似文献