Effort has a greater effect on test scores than severe brain injury in compensation claimants.

Nine-hundred and four consecutive patients, including 80 neurological patients and 470 with head injuries, were given neuropsychological tests. All 43 test scores were converted to normative Z-scores and averaged, giving an Overall Test Battery Mean (OTBM). A variable measuring effort correlated 0.73 with the OTBM. The OTBM mean score was 1.20 SD lower in those who failed the Word Memory Test (WMT) than in those who passed the WMT. Sub-optimal effort suppressed the OTBM 4.5 times more than did moderate-severe brain injury. When only those making a good effort were included, patients with severe brain injuries and neurological diseases scored significantly lower than groups presumed to have no neurological impairment, but these group differences were not seen when all cases were analysed together. These data illustrate the importance of measuring and controlling for sub-optimal effort in individual neuropsychological evaluations, as well as in empirical research with similar groups of patients.

A comparison of complaints by mild brain injury claimants and other claimants describing subjective experiences immediately following their injury.

This study compares the rate of postconcussive (PCS) symptoms at the time of injury for mild traumatic brain injury (MTBI; N=24) claimants and claimants reporting other forms of injury (OI; N=66). On checklists surveying their complaints immediately after their injury, MTBI and OI claimants reported similar levels of many PCS complaints, e.g., dazed, confused, dizzy, disoriented, trouble concentrating, numbness or loss of sensation, and loss of memory for some of what happened. One in four of the OI samples reported partial loss of consciousness (LOC), and one-third reported loss of memory for some of what happened. About 67% of the MTBI sample reported being confused and 71% dazed, but so did many of the OI sample (52% dazed, 65% confused). The authors suggest that classical PCS complaints experienced immediately after an injury are so nonspecific that they have little diagnostic specificity.

Disclosure of tests and raw test data to the courts: a need for reform.

Psychologists' current practices with respect to the disclosure of tests and raw test data to courts are damaging their reputations as scientists, undermining their credibility as honest professionals acting in good faith, and contrary to the best interests of consumers. The profession is conducting itself in a contradictory fashion that deserves reform. There is need for an interdisciplinary panel drawn from the American Psychological Association and American Bar Association to develop reasonable procedures for disclosure of tests and test data in legal proceedings. These procedures should be developed with input from experienced psychological expert witnesses, attorneys, and judges from a variety of state and federal jurisdictions, diverse geographical areas, and different types of legal proceedings. This expert panel should also address the issue of attorney coaching of clients in preparation for assessment by psychologists.

Methodology in epidemiological studies of human neurobehavioral toxicity: a case study with critical review.

Health care professionals and government decision makers concerned with neurotoxicity increasingly rely on neuropsychological research studies. An example is an article relied upon by the U.S. Environmental Protection Agency that reported effects on neurobehavioral performance in a group of factory workers exposed to toluene by Foo, Jeyaratnam, and Koh in 1990, which is described as lacking reliability and as having implausible contents. A critical review can serve as an educational tool for neuropsychologists, to emphasize the need to design and document their research and interpret findings without speculation. For example, in the Foo, et al. study the implications of the findings for the general population cannot be interpreted. To conclude that this study has identified toluene as the cause of neurobehavioral deficits is a leap of inference far exceeding the power in their study. The review underscores the need for more critical reviews of research relied upon by decision makers and researchers.

Comment: Warning malingerers produces more sophisticated malingering.

Warning persons that attempts to malinger on neuropsychological testing will be detected is not an effective way of reducing malingering behavior. Rather, the literature on coaching consistently shows that malingerers who are warned of the presence of symptom validity assessment techniques are able to feign deficits in a less exaggerated and more believable fashion and therefore elude detection. Warning persons about the presence of these techniques reduces the validity and scientific quality of forensic evaluations. Rather than warning persons that they will be caught if they try to malinger, we recommend that persons be told to do their best and that forensic examiners encourage maximum effort, consistent with accepted testing practices and test manual instructions.

Research on chronic, low-level exposure to formaldehyde: implications for neuropsychological assessment.

Findings from empirical research serve as the foundation for neuropsychological assessment of individuals suspected of exposure to formaldehyde. Insofar as conclusions regarding causal relationships between exposure and neuropsychological deficits are based on research methodologies that are reliable, findings can be informative. Unfortunately, existing research is not rooted in sound methodology and findings may mislead rather than enlighten clinicians. Two prominent shortcomings in formaldehyde research are discussed: selection bias in recruitment of research participants and unreliability of participant recall for obtaining data on important background variables and exposure levels. Selected examples illustrate the influence of these shortcomings on research showing a causal relationship between long-term, low-level exposure to formaldehyde and chronic neurobehavioral deficiencies. The implications of these weaknesses for assessment of individual patients are discussed.

Application of the Postconcussive Syndrome Questionnaire with medical and psychiatric outpatients.

The Postconcussive Syndrome Questionnaire (PCSQ; Lees-Haley, 1992) was previously found (Axelrod, Fox, Lees-Haley, Earnest, Dolezal-Wood, & Goldman, 1996) to produce four factors, named Psychological, Somatic, Cognitive, and Infrequency. These four factors of the questionnaire were evaluated across five groups of medical and psychiatric outpatients. The patients were from neurology, mental health, family practice, and internal medicine clinics as well as from a clinic that evaluated new patients to a health maintenance organization. Mental health patients had greater psychological symptoms and fewer health concerns than the other groups. Neurology patients differed from the other groups by having greater Infrequency symptoms. Patients who were referred for their screening evaluation or were seen by internal medicine had fewer overall symptoms than the other three patient groups. The data from this study provide support for the use of the PCSQ as a multifactorial self-report measure of symptom presentation.

Effect of information about odor on causal ascriptions for illness.

The effect of information about detection of an odor on causal ascriptions for illness was investigated. In four different scenarios perceptions regarding the cause of a hypothetical symptomatic experience were compared for events described with and without an odor. Participants (N = 106) were asked to imagine themselves becoming ill after engaging in several common experiences, including pumping gasoline at a service station. In two scenarios participants read that they smelled an offensive odor while pumping the gasoline whereas in two other scenarios no information about an odor was provided. Further, information about gasoline described with or without odor was presented either early or late in the stimulus paragraphs. All participants then responded to questions including an open-ended question asking them to make causal attributions for their illness. Participants in the odor-suggested group ascribed the cause of illness more frequently to gasoline and perceived the probability of other potential causes as lower than did participants in the nonodor suggested group. Findings suggest that peoples' implicit theories about toxicity contain causal connections between malodorous stimuli and illness. The implications of implicit theories for perception of illness are discussed.

Response bias in plaintiffs' histories.

This study investigated response bias in self-reported history of factors relevant to the assessment of traumatic brain injury, toxic brain injury and related emotional distress. Response bias refers to systematic error in self-report data. A total of 446 subjects (comprising 131 litigating and 315 non-litigating adults from five locations in the United States) completed a symptom questionnaire. Data were obtained from university faculty and students, from patients in clinics specializing in physiatry neurology, and family medicine, and from plaintiffs undergoing forensic neuropsychological evaluations. Comparisons were made for litigant and non litigant ratings of their past and current cognitive and emotional functioning, including life in general, ability to concentrate, memory, depression, anxiety, alcohol, drugs, ability to work or attend school, irritability, headaches, confusion, self-esteem, and fatigue. Although there is no basis for hypothesizing plaintiffs to be healthier than the general population, plaintiffs rated their pre-injury functioning superior to non-plaintiffs. These findings suggest that response biases need to be taken into account by forensic examiners when relying on litigants' self-reports of pre-injury status.

Neurotoxicity of chronic low-dose exposure to organic solvents: a skeptical review.

The health effects of long-term, low-level exposure to organic solvents have been studied for many years. While the volume of literature is great, definitive conclusions regarding chronic neurobehavioral effects of environmental exposure are premature. Methodological shortcomings in research preclude confidence in studies allegedly supporting a causal link between chronic low-dose solvent exposure and lasting neurobehavioral deficits. In this article, the shortcomings reviewed include selection bias in recruitment of research subjects, overreliance on subjective recall in determining levels and duration of exposure, between-study variability in kinds of solvents examined, variability in tests selected to assess neurobehavioral functioning, and diversity in reported findings. The implications of these for characterizing the state of organic solvent research are discussed.

MMPI-2 base rates for 492 personal injury plaintiffs: implications and challenges for forensic assessment.

This study reports base rates of MMPI-2 clinical scales. PTSD scales, and validity scales for 492 personal injury plaintiffs, 230 men and 262 women. Scales studied included L, F, K, F minus K, Ds-r, Fake Bad, Ego Strength, Back F. Total Obvious minus Subtle, VRIN, and TRIN. Forensic high points resembled outpatient profiles but not the MMPI-2 psychiatric sample and shared only code type 13/31 with the normative sample. The most common two-point code type for men was 13/31, followed by 12/21 and 23/32, and for women was 13/31, followed by 23/32 and 12/21. Fifty percent of the forensic sample were code type 13/31, 12/21, or 23/32. Validity measures suggested possible malingering on approximately 20 to 30% of the profiles but the majority of profiles were valid. Validity problems discussed include attorney coaching and the congruence of plaintiff personality characteristics with the demand characteristics of litigation. Examples of attorney coaching are provided. The modal plaintiff appears to be an unhappy somatizer involved in a social context which encourages rationalization, projection of blame, and complaining.

Neurobehavioral assessment in toxic injury evaluations.

Forensic neurobehavioral evaluations present special validity problems such that standard assumptions, procedures, histories, and fact-finding methods used in treatment settings may be inappropriate and misleading. This article discusses basic issues in assessing the quality and reasonableness of forensic toxic injury evaluations. Topics include selection of test instruments, history, functional assessment, threats to validity, voluntary manipulation of test results, chemophobia, limitations of the state of the art in neuropsychology and neurobehavioral assessment, base rates, and norms. Understanding the roles these topics play in toxic injury evaluations is essential to making informed judgments about the quality of forensic neurobehavioral evaluations.

The implications of limitations in hydrocarbon research for neuropsychological assessment.

As neuropsychologists are involved increasingly in the neuropsychological assessment of individuals reporting both acute and long-term exposure to hydrocarbons, the value of research for providing guidance also increases. Research findings inform neuropsychologists about likely neuropsychological deficits given certain intensity and duration of exposure and about neuropsychological tests most appropriate for detecting hydrocarbon-induced deficits. Although high-dose events are associated with neuropsychological deficits, methodological weaknesses in the existing research impede a consensus on the implications of low-dose exposures in humans. Three flaws inherent in research on low-dose hydrocarbon exposures and their implications for neuropsychological assessment of individuals are discussed: Selection bias in recruitment of research participants, biased recall of research participants, and between-study variation in neuropsychological tests and results. Because they undermine the reliability and validity of existing research, lack of awareness of these weaknesses may interfere with unbiased assessment of individual patients suspected of hydrocarbon-induced neuropsychological deficits. Examples from the social-cognitive psychological literature contribute to understanding how misleading research findings can lead experts to form expectancies that bias assessment of individuals.

Response bias in self-reported history of plaintiffs compared with nonlitigating patients.

Response bias refers to systematic error in the data produced by patients or research subjects, e.g., due to erroneous recall or reporting. In forensic settings, response bias appears to be associated with the nature of the proceedings. The present study tested whether patients in litigation exhibit different response patterns than nonlitigating patients when asked about their preinjury problems. 34 litigants and 80 nonlitigants rated various areas of cognitive and emotional functioning as problematic in the past and currently. The primary finding was that plaintiffs reported pre-injury functioning superior to that of controls. These findings suggest the need for caution in inferences that litigants are either reliable or deceitful because response biases may affect self-reports in a misleading fashion.

Neurotoxicity of chronic low-level exposure to organic solvents: caveats for applied neuropsychologists.

Research findings on the neuropsychological consequences of chronic low-level exposure to organic solvents are equivocal. Because methodological weaknesses cast doubt on some empirical publications that report causal links between occupational exposure and irreversible neuropsychological deficits, findings can mislead rather than inform neuropsychological assessment. Empirical articles often do not provide enough information to support the conclusions offered or to evaluate the reasoning by which the conclusions were reached. This article discusses some prototypical weaknesses in empirical articles and illustrates these weaknesses with selected examples. The contribution that neuropsychologists can make to improve the quality of research is discussed.

Neurobehavioral assessment in toxic injury evaluations.

Forensic neurobehavioral evaluations present special validity problems such that standard assumptions, procedures, histories, and fact-finding methods used in treatment settings may be inappropriate and misleading. This article discusses basic issues in assessing the quality and reasonableness of forensic toxic injury evaluations. Topics include selection of test instruments, history, functional assessment, threats to validity, voluntary manipulation of test results, chemophobia, limitations of the state of the art in neuropsychology and neurobehavioral assessment, base rates, and norms. Understanding the roles these topics play in toxic injury evaluations is essential to making informed judgments about the quality of forensic neurobehavioral evaluations.

Neurotoxic complaint base rates of personal injury claimants: implications for neuropsychological assessment.

This study reports base rate data for 113 family practice patients with no history of head trauma or toxic exposure, 68 family practice patients with a history of head trauma or toxic exposure, and 156 personal injury claimants with no history of toxic exposure or head trauma who presented for a psychological evaluation due to emotional distress. Personal injury claimants reported suffering from significantly more neurotoxic and neuropsychologic symptoms than subjects with a reported history of head trauma and/or toxic exposure. The authors urge that evaluating psychologists consider the base rate of these symptoms in litigating populations and use caution in relying on self-reported symptoms as evidence of injury when patients are in litigation.

Interrelationship of MMPI-2 validity scales in personal injury claims.

A sample of MMPI-2s of worker's compensation and personal injury cases (N = 289) was gathered to examine the relationship of various indicators of exaggeration. Intercorrelations of the F, F-K, the MMPI Dissimulation Scale-revised (Ds-r), total of obvious minus subtle scales (O-S), Fake Bad Scale (FBS), VRIN, and TRIN were computed and the relative sensitivity of each score calculated using various cut-offs. Factor analysis suggests that malingering may take the form of inconsistent responding as well as symptom exaggeration. Patients evaluated at the request of plaintiff attorneys showed a seemingly greater degree of symptom exaggeration and inconsistent responding than did those referred by defense counsel.