Ernest H. Harrell

Feigning neuropsychological impairment: A critical review of methodological and clinical considerations

Abstract Despite a burgeoning literature on malingering, clinicians have few assessment tools for the accurate classification of those persons feigning cognitive and neuropsychological deficits. We examine problems inherent in the validation of these assessment measures. We identify and discuss six potential strategies for the detection of feigned neuropsychological deficits: (a) floor effect, (b) symptom validity testing (SVT), (c) performance curve, (d) magnitude of error, (e) atypical presentation, and (f) psychological sequelae. In light of the available research, we critically review specific methods which incorporate these strategies. We found that Reys 15-Item Memory Test, as a measure of floor effect, had very low sensitivity rates. We also found considerable variability in SVT methods; a computerized version of SVT (Pritchard & Moses, 1991) that measured auditory, visual, and memory abilities had a satisfactory sensitivity of 67%. Overall, strategies that employed performance curves appeared to have the greatest promise in identifying potential malingerers. The remaining three detection strategies have not been adequately tested .

Attenuation of response deficits by electroconvulsive shock

Rats previously exposed to inescapable footshock were inferior to nonshocked rats in acquiring a shock-escape response. In three separate experiments, these response deficits were improved by electroconvulsive shock (ECS) given 1 h prior to testing. Subsequent experiments suggested that this effect cannot be attributed to ECS-induced (1) retrograde amnesia, (2) decreased shock thresholds, or (3) increased general activity.

Biofeedback and Control of Skin Cell Proliferation in Psoriasis

The present study was designed to determine the effect of skin-temperature-biofeedback training on cellular proliferation in three psoriasis patients. It was hypothesized that (a) psoriasis patients would be able consciously to decrease skin temperature of psoriatic tissue and (b) there would be a positive correlation between rate of cellular proliferation and temperature change. Results obtained indicated biofeedback training to be effective in decreasing the surface temperature of psoriatic tissue. Temperature-training effects generalized from the location of the thermistor to the contralateral limb. Rate of cellular proliferation decreased from pretraining to post-training biopsies. Dramatic improvement in psoriatic plaques was usually observed up to 4 mo. posttraining.

Psychophysiological Effects of A Running Program on Depression and Anxiety in A Psychiatric Population

The purpose of the present study was to investigate the psychophysiological effects of exercise on measures of cardiovascular fitness, depression, and anxiety in a psychiatric population. In addition to self-report measures, electromyographic assay and digital skin temperature were performed in order to measure physiological concomitants of anxiety. Subjects in the running treatment group ran 3 days per week while subjects in the corrective therapy group were involved in noncardiovascular exercise for 1 hour, three times per week. Including the waiting list control group, 27 subjects completed the study. Statistical results demonstrated significant improvements in cardiovascular conditioning for the running treatment group, and significant decrements in depression for the running treatment group compared to the waiting list controls. Results of electromyographic activity demonstrated that the running treatment group was significantly less tense. No significant findings were observed on digital skin temperature or body composition assay.

The Influence of Hostility and Family History of Cardiovascular Disease on Autonomic Activation in Response to Controllable versus Noncontrollable Stress, Anger Imagery Induction, and Relaxation Imagery

Autonomic activation in response to controllable versus noncontrollable stress, anger imagery induction, and relaxation imagery was studied among 80 participants between the ages of 18 and 34 years. Participants differed in level of trait hostility and family history of cardiovascular disease. Results were obtained through power spectral analyses of electrocardiograph R-R intervals, which produced an index of autonomic nervous system activation. For both male and female populations, parasympathetic regulation was diminished during anger induction for individuals with high levels of trait hostility and having a family history of cardiovascular disease. Similar results were obtained for women during the uncontrolled stress condition. Based on family history of cardiovascular disease and trait hostility, men responded differentially to relaxation imagery induction, whereas no differences were found among females.

Cognitive deficits in schizophrenia on the WAIS‐R NI sentence arrangement subtest

Performance of participants diagnosed with schizophrenia on the Sentence Arrangement subtest of the WAIS-R NI and several tests sensitive to frontal lobe dysfunction was significantly poorer than that of manic depressive or control participants. Several measures of performance of patients diagnosed with schizophrenia on the WAIS-R NI Sentence Arrangement subtest appeared to support recent interpretations of the cognitive deficit seen in schizophrenia. These data represent the first demonstration of deficit performance by patients with schizophrenia on the Sentence Arrangement subtest. This is also supportive of the prediction that one of the areas whose activity may influence scores on this subtest is the prefrontal cortex. In addition, neither positive nor negative symptoms systematically correlated with the cognitive deficits reported despite specific predictions from the current literature.

Medial hypothalamic stimulation decreases the phagocytic activity of the reticuloendothelial system

Although research has linked the central nervous system with changes in immunoresponsivity, research on the possible role of the central nervous system in altering reticuloendothelial activity is lacking. This study investigated the possible relationship between hypothalamic structures and changes in responsivity of the reticuloendothelial system. Eight male albino rats received bilateral electrode implants in the ventromedial area of the hypothalamus, and, following brain stimulation, reticuloendothelial activity was assessed 3, 6, 12, 24, and 96 h after stimulation. Brain stimulation decreased phagocytic activity of the reticuloendothelial system. These findings may increase our understanding of a possible neural mechanism underlying relationships between stress and resistance to disease states.

Nucleus circularis and lateral preoptic regulation of osmotic thirst

Small bilateral lesions of the nucleus circularis in rats produced a deficit in osmotic thirst, whereas subjects with similar-sized lesions of the lateral preoptic hypothalamus were almost identical to sham-operated rats in response to an osmotic challenge. Therefore, osmosensitive cells probably are more concentrated in the area of the nucleus circularis than in the lateral preoptic area. However, moderate-sized lesions in the lateral preoptic area resulted in a deficit in osmotic thirst, particularly when the damage was posterior to the anterior commissure. This research suggested that osmosensitive cells are diffusely represented in the preoptic area but become more concentrated in the anterior hypothalamus. This conclusion raised questions about the functional importance of the preoptic for osmoregulation and pointed to a more critical role for the nucleus circularis.

Effects of Delay of Extinction on Resistance to Extinction

The principal hypothesis of this study was that delaying the onset of extinction trials would decrease resistance to extinction and eliminate or greatly reduce the partial reinforcement extinction effect. Subjects were 137 Sprague-Dawley female rats, approximately 60 days old at the start of training. The task was standard bar-press training, with Noyes pellets as reinforcers. Subjects were randomly assigned to one of four reinforcement schedules (CRF, FR:4, FR:8, FR:12), and to one of three delay groups (1-day, 7-day, 31-day). The dependent variable was number of responses to extinction (no responses in 5 continuous min.). The results indicated that a long delay between acquisition and extinction trials is associated with a decreased resistance to extinction under several schedules of reinforcement. The partial reinforcement extinction effect was greatly reduced and differences among various FR schedules eliminated at the 31-day delay period.

Reversal of Learned Helplessness by Peripheral Arousal

The response deficit produced by uncontrollable shock has been termed learned helplessness. Many studies have demonstrated similarities between human depression and learned helplessness. However, pilot studies suggested that sympathomimetic drugs which do not alleviate depression may alter learned helplessness. The present study was designed to replicate these preliminary data. 32 rats were exposed to either no-shock or a sequence of inescapable shock previously shown to produce learned helplessness. 24 hr. later metaraminol bitartrate (Aramine) or physiological saline was injected prior to the testing in a bar-press, shock-escape task. Inescapable shock one day prior to testing produced a severe response deficit in saline controls but not in the drug group. Reversal of learned helplessness by peripheral autonomic arousal indicates a reevaluation of the learned helplessness model of human depression may be necessary.