Jeffrey M. Love

WAIS digit span-based indicators of malingered neurocognitive dysfunction: classification accuracy in traumatic brain injury.

The present study determined specificity and sensitivity to malingered neurocognitive dysfunction (MND) in traumatic brain injury (TBI) for several Wechsler Adult Intelligence Scale (WAIS) Digit Span scores. TBI patients (n = 344) were categorized into one of five groups: no incentive, incentive only, suspect, probable MND, and definite MND. Performance of 1,063 nonincentive patients (e.g., cerebrovascular accident, memory disorder) was also examined. Digit Span scores included reliable digit span, maximum span forward both trials correct, maximum span forward, combined maximum forward and backward span, Digit Span scaled score, maximum span backward both trials correct, and maximum span backward. In TBI, sensitivity to MND ranged from 15% to greater than 30% at specificities of 92% to 98%. Patient groups with documented brain pathology had higher false-positive error rates. These results replicate previous known-groups malingering studies and provide valuable data supporting the WAIS Digit Span scores in detection and diagnosis of malingering.

Sensitivity and Specificity of MMPI-2 Validity Scales and Indicators to Malingered Neurocognitive Dysfunction in Traumatic Brain Injury

The present study used a known-groups design to determine the classification accuracy of 10 MMPI-2 validity scales and indicators in the detection of cognitive malingering in traumatic brain injury. Participants were 259 traumatic brain injury and 133 general clinical patients seen for neuropsychological evaluation. The TBI patients were subdivided into groups based on a comprehensive examination of effort following Slick, Sherman, and Iversons (1999) criteria. More extreme scores demonstrated excellent specificity; often impressive sensitivity was seen even while maintaining a low false positive error rate. Specificity was good even in stroke, memory disorder, and psychiatric patients without incentive. The results of this study are presented in frequency tables that can be easily referenced in clinical practice.

Wisconsin Card Sorting Test in chronic severe traumatic brain injury: factor structure and performance subgroups

Objective : The present study further investigated the factor structure of the WCST in traumatic brain injury and investigated the construct validity and relationships among scores through the use of cluster analysis. Design : Participants were 68 survivors of chronic severe TBI, living at a residential brain injury rehabilitation facility. Methods and procedures : Three sets of WCST scores were submitted to factor analysis; the regression factor scores based on the standard WCST were examined using cluster analysis. Results : Factor analysis of the WCST raw scores replicated the three-factor solution which has been previously reported. When t -scores were analysed, two-to-four-factor solutions could be justified. The cluster analysis identified four groups representing: (1) impaired response maintenance; (2) problem-solving deficits; (3) intact WCST performance; and (4) deficits in set shifting. Conclusions : The results support previous research indicating that the WCST is sensitive to three distinct cognitive processes: cognitive flexibility, problem-solving, and response maintenance. However, unlike the cognitive processes underlying WCST performance, the WCST scores representing these processes are not independent. The potential clinical relevance of these results is discussed.

Definite Malingered Neurocognitive Dysfunction in Moderate/Severe Traumatic Brain Injury

There has been disagreement in the literature about whether persons with documented neuropathology can be diagnosed as malingering. To address this question, we present three moderate severe traumatic brain injury patients who were evaluated in the context of litigation who met the Slick, Sherman, and Iverson (1999) criteria for a diagnosis of “Definite Malingered Neurocognitive Dysfunction.” Each performed significantly below-chance on at least one forced-choice symptom validity test, thereby demonstrating a deliberate attempt to appear impaired. These cases represent the first definitive evidence of an intentional effort to appear impaired in the context of documented moderate/severe traumatic brain injury.

Malingering in Toxic Exposure. Classification Accuracy of Reliable Digit Span and WAIS-III Digit Span Scaled Scores.

This study examined the sensitivity and false-positive error rate of reliable digit span (RDS) and the WAIS-III Digit Span (DS) scaled score in persons alleging toxic exposure and determined whether error rates differed from published rates in traumatic brain injury (TBI) and chronic pain (CP). Data were obtained from the files of 123 persons referred for neuropsychological evaluation related to alleged exposure to environmental and industrial substances. Malingering status was determined using the criteria of Slick, Sherman, and Iverson (1999). The sensitivity and specificity of RDS and DS in toxic exposure are consistent with those observed in TBI and CP. These findings support the use of these malingering indicators in cases of alleged toxic exposure and suggest that the classification accuracy data of indicators derived from studies of TBI patients may also be validly applied to cases of alleged toxic exposure.

Malingering detection with the Wisconsin Card Sorting Test in mild traumatic brain injury.

This study evaluates the ability of several Wisconsin Card Sorting Test (WCST; Psychological Assessment Resources, 1990) variables to detect malingering in mild traumatic brain injury (TBI). The sample consisted of 373 TBI patients and 766 general clinical patients. Classification accuracy for seven indicators is reported across a range of injury severity and scores levels. Overall, most WCST scores were ineffective in discriminating malingering from non-malingering mild TBI patients. Failure-to-Maintain-Set, the Suhr & Boyer formula, and the King et al. formula detected about 30% of malingerers at cutoffs associated with a false positive error rate of ≤11%. The clinical interpretation and use of these indicators are discussed.

Comparability of the standard WCST and WCST-64 in traumatic brain injury.

The aim of this study was to investigate the comparability of the Wisconsin Card Sorting Test short form (WCST-64) to the standard form in a clinical population with documented brain pathology: chronic severe traumatic brain injury (TBI). Participants were 61 patients at least 1 year after severe TBI living at a large residential rehabilitation facility. The WCST was administered in standard fashion with both the standard and 64-card versions scored. All derived scores with norms were examined. Results indicated that the WCST-64 scores were comparable to the standard version, and assigned impairment levels remained relatively stable. These results suggest the WCST-64 is a valid alternative to the standard version in chronic severe TBI.

Temporal stability of the Wisconsin Card Sorting Test in a chronic traumatic brain injury sample.

The aim of the present study was to investigate the temporal stability of the Wisconsin Card Sorting Test (WCST) in a clinical population with documented brain pathology, stable cognitive deficits, and for whom repeated testing is common: chronic severe traumatic brain injury (TBI). Participants were 34 patients at least 1 year postsevere TBI living at a large residential rehabilitation facility. The WCST was administered in standard fashion with both the standard and 64-card versions scored. All derived scores with norms were examined. Results indicated acceptable temporal stability of most scores for both the standard and short WCST, although the stability of the WCST-64 was poorer than for the standard WCST. Three sets of significant change indices are provided for clinical use.

Psychological evaluation of the emotional effects of a community toxic exposure.

Objective:We sought to assess the emotional effects of a major community toxic release while controlling the potential effects of response bias associated with litigation. Methods: Participants included 152 exposed adult litigants and a matched unexposed comparison group (n = 76). Psychological assessment methods included: (1) Minnesota Multiphasic Personality Inventory-2; (2) Symptom Checklist-90-Revised; and (3) Impact of Event Scale-Revised. Results:Ten to 40% of the exposed group demonstrated emotional distress (compared with a 5% comparison baseline) depending on indicator and cutoff score used. Conclusions:The psychological consequences of a community toxic exposure were present even when exaggeration was carefully controlled. Accounting for exaggeration in the assessment of subjective psychological complaints provides a more accurate view of the subjective emotional state of persons who have experienced toxic exposure thereby facilitating appropriate clinical management of their mental health needs.

Classification accuracy of the Portland digit recognition test in persons claiming exposure to environmental and industrial toxins

The classification accuracy of the Portland digit recognition test (PDRT) in detecting cognitive malingering was studied in patients claiming cognitive deficits due to exposure to environmental or industrial toxins. Twenty-nine patients alleging toxic exposure and who met Slick et al. [Slick, D. J., Sherman, E. M. S., & Iverson, G. L. (1999). Diagnostic criteria for malingering neurocognitive dysfunction: Proposed standards for clinical practice and research. The Clinical Neuropsychologist, 13, 545-561] criteria for malingered neurocognitive dysfunction were compared to 14 toxic exposure patients negative for evidence of malingering. The published cutoffs were associated with a false positive error rate of 0% and sensitivity of more than 50%. When criterion for a PDRT failure was a positive PDRT finding on more than one section, the FP rate remained 0% while sensitivity improved to about 70%. The results indicate that a failed PDRT is an indication of malingering and not the neurological effect of a toxic substance or some other clinical phenomenon. The PDRT can be used with confidence as an indicator of negative response bias in cases of alleged exposure to neurotoxic substances.