Reactions to chemical exposures often include fears of future illness, cancerphobia, reports of m... more Reactions to chemical exposures often include fears of future illness, cancerphobia, reports of multiple chemical sensitivity, and other ill-defined complaints. Frequently, these complaints occur at levels of exposure not known to cause physiological harm. Although frequently dismissed as hysterical or hypochondriacal reactions, these complaints, along with other indefinite symptoms, may be better understood in terms of biases in perception and reporting. In this paper, we outline various sources of perceptual and response biases including prior beliefs, the media, influential others, reconstructed personal histories, self-perceptions, and the forensic environment. It is recommended that a thorough understanding of symptom-reporting and psychological distress following a chemical exposure involves consideration of these issues.
Organophosphates are among the most commonly used and most toxic pesticides. They act directly on... more Organophosphates are among the most commonly used and most toxic pesticides. They act directly on the nervous system by inhibiting the neurotransmitter acetylcholine. Organophosphates evoke a consistent pattern of physical symptoms. They also have acute psychological and behavioral effects, such as anxiety, depression, and cognitive impairments. Research suggests that moderate levels of acute poisoning may cause persistent problems. Long-term psychological effects of low-level exposure, however, have not been determined satisfactorily. Some research has documented cognitive and emotional deficits due to chronic exposure to organophosphates, but not all studies have found ill effects. To date, psychologists have played only a small role in studying the psychological effects of organophosphates, despite the substantial contribution their expertise could make.
Converging lines of evidence suggest that attorneys are influencing data relied upon by psycholog... more Converging lines of evidence suggest that attorneys are influencing data relied upon by psychological experts in forensic cases. This is a problem because a consequence of attorney prompting may be invalid expert opinions that mislead rather than inform the trier of fact. Attorneys influence psychological data by a variety of means. They advise their clients how to respond to psychological tests, make suggestions of what to tell examining psychologists and what to emphasize, and lead patients not to disclose certain information important to psychologists. The purpose of this article is to alert psychologists to a growing threat to the validity of psychological and neuropsychological evaluations in forensic matters. Several examples of attorney preparation of clients for examinations are described.
Three primary purposes: 1) Measure the extent to which effort accounts for the statistical varian... more Three primary purposes: 1) Measure the extent to which effort accounts for the statistical variance in neuropsychological tests. 2) Identify the best predictor of test performance among several independent variables, including measures of effort, age, education, and diagnosis. 3) Determine the degree of influence that effort has on ability test scores in contrast to brain injury severity and neurological disease.
The first purpose of the current study was to measure the extent to which effort affects the stat... more The first purpose of the current study was to measure the extent to which effort affects the statistical variance in neuropsychological tests and also in symptom reporting scales in a large clinical sample of people undergoing neuropsychological assessment for purposes of evaluating eligibility for financial compensation. A second purpose was to identify the best predictor of test performance among several possible predictors, including measures of effort and also other variables, such as intelligence, age and diagnosis. The analysis included a ranking of several effort measures for predictive power. Finally, a third purpose was to rank several clinical measures in terms of their apparent sensitivity or vulnerability to suboptimal effort.
This paper presents a scale for using the Minnesota Multiphasic Personality Inventory-2 for the d... more This paper presents a scale for using the Minnesota Multiphasic Personality Inventory-2 for the detection of malingerers in personal injury claims. Data are reported for personal injury claimants and for medical outpatients simulating emotional distress caused by motor vehicle accidents, industrial stress, and toxic exposure. Criterion problems are discussed. The answers and scored directions are presented in an appendix to the paper.
Reactions to chemical exposures often include fears of future illness, cancerphobia, reports of m... more Reactions to chemical exposures often include fears of future illness, cancerphobia, reports of multiple chemical sensitivity, and other ill-defined complaints. Frequently, these complaints occur at levels of exposure not known to cause physiological harm. Although frequently dismissed as hysterical or hypochondriacal reactions, these complaints, along with other indefinite symptoms, may be better understood in terms of biases in perception and reporting. In this paper, we outline various sources of perceptual and response biases including prior beliefs, the media, influential others, reconstructed personal histories, self-perceptions, and the forensic environment. It is recommended that a thorough understanding of symptom-reporting and psychological distress following a chemical exposure involves consideration of these issues.
Organophosphates are among the most commonly used and most toxic pesticides. They act directly on... more Organophosphates are among the most commonly used and most toxic pesticides. They act directly on the nervous system by inhibiting the neurotransmitter acetylcholine. Organophosphates evoke a consistent pattern of physical symptoms. They also have acute psychological and behavioral effects, such as anxiety, depression, and cognitive impairments. Research suggests that moderate levels of acute poisoning may cause persistent problems. Long-term psychological effects of low-level exposure, however, have not been determined satisfactorily. Some research has documented cognitive and emotional deficits due to chronic exposure to organophosphates, but not all studies have found ill effects. To date, psychologists have played only a small role in studying the psychological effects of organophosphates, despite the substantial contribution their expertise could make.
Converging lines of evidence suggest that attorneys are influencing data relied upon by psycholog... more Converging lines of evidence suggest that attorneys are influencing data relied upon by psychological experts in forensic cases. This is a problem because a consequence of attorney prompting may be invalid expert opinions that mislead rather than inform the trier of fact. Attorneys influence psychological data by a variety of means. They advise their clients how to respond to psychological tests, make suggestions of what to tell examining psychologists and what to emphasize, and lead patients not to disclose certain information important to psychologists. The purpose of this article is to alert psychologists to a growing threat to the validity of psychological and neuropsychological evaluations in forensic matters. Several examples of attorney preparation of clients for examinations are described.
Three primary purposes: 1) Measure the extent to which effort accounts for the statistical varian... more Three primary purposes: 1) Measure the extent to which effort accounts for the statistical variance in neuropsychological tests. 2) Identify the best predictor of test performance among several independent variables, including measures of effort, age, education, and diagnosis. 3) Determine the degree of influence that effort has on ability test scores in contrast to brain injury severity and neurological disease.
The first purpose of the current study was to measure the extent to which effort affects the stat... more The first purpose of the current study was to measure the extent to which effort affects the statistical variance in neuropsychological tests and also in symptom reporting scales in a large clinical sample of people undergoing neuropsychological assessment for purposes of evaluating eligibility for financial compensation. A second purpose was to identify the best predictor of test performance among several possible predictors, including measures of effort and also other variables, such as intelligence, age and diagnosis. The analysis included a ranking of several effort measures for predictive power. Finally, a third purpose was to rank several clinical measures in terms of their apparent sensitivity or vulnerability to suboptimal effort.
This paper presents a scale for using the Minnesota Multiphasic Personality Inventory-2 for the d... more This paper presents a scale for using the Minnesota Multiphasic Personality Inventory-2 for the detection of malingerers in personal injury claims. Data are reported for personal injury claimants and for medical outpatients simulating emotional distress caused by motor vehicle accidents, industrial stress, and toxic exposure. Criterion problems are discussed. The answers and scored directions are presented in an appendix to the paper.
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Papers by Paul Lees-Haley