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Query: UMLS:C0015672 (fatigue)
 51,768 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

This study attempted to evaluate the validity of self-reports of memory deficits in narcoleptics by comparing the scores of these patients with the scores of matched control subjects on standardized tests of memory function. After completing a short interview designed to elicit qualitative information about memory difficulties, 30 narcoleptic subjects and 30 control subjects completed the Wechsler Memory Scale (WMS), Rey-Auditory Verbal Learning Test, the Rey Complex Figure Test, Strub and Black's List of Letters, and the Symbol Digits Modalities Test (SDMT). In addition, the Profile of Mood States (POMS) was used to detect variation in performance due to anxiety or fatigue. Continuous polygraphic recordings were obtained during the testing to detect any changes in alertness. Subjects with narcolepsy experienced more difficulty in maintaining attention than control subjects, as evidenced by significantly more perseveration errors (p less than or equal to 0.01) on Strub and Black's List of Letters. Despite differences in their ability to sustain attention, there were no significant differences between narcoleptic and control subjects on measures of concentration (Digit Span from the WMS, and the SDMT). Furthermore, there was no objective evidence of memory impairment when the scores of narcoleptic and control subjects were compared on standardized tests of immediate and delayed recall, as well as on tests of verbal and visual memory.
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PMID:Tests of memory in narcoleptics. 230 68

50 right-handed men were evaluated on right and left hand-grip strength, fatigue, and perseveration tasks and on a finger-tapping task. Subjects were tested in combined ambient sensory conditions of bright light and noise, bright light and quiet, dim light and noise, and dim light and quiet to provide an initial test of asymmetrical activation of the hemispheres. Analysis did not support the hypothesized asymmetry in activation. However, increased fatigue and perseveration were found using the left hand.
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PMID:Manual dexterity, strength, fatigue, and perseveration: an initial test of asymmetry in cerebral activation. 237 6

The influence of depression on the cerebral hemispheric motor functioning of 40 right-handed women, half of whom had been classified as depressed, the other half as nondepressed, was examined. The depressed women were also characterized by elevated state and trait anxiety, suggestive of an anxious-depressive state with heightened arousal. A hand dynamometer was used as a standardized measure of hemispheric motor functioning such as hand-grip strength, perseveration, and fatigue. Primary findings indicated that depressed women displayed significantly less perseveration at the left hand than did nondepressed women, but a nonsignificant trend only was noted for less perseveration at the right hand. These results suggest possible differential arousal of the left and right cerebral hemispheres in this sample of anxious-depressed women and are discussed in terms of arousal theory.
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PMID:Functional asymmetry in the motor performances of women: neuropsychological effects of depression. 793 60

The effects of combinations of bright or dim light and noise levels on hand strength, fatigue, motor perseveration, and tapping rate were evaluated in 13 undergraduate and 13 elderly females. Increments in the intensity of sensory conditions produced opposite effects on grip strength at the left, as opposed to the right hand. Reliable asymmetry in hand strength (right > left) was observed in bright but not dim lighting in the younger group. In the elderly group, the extent of asymmetrical hand strength was related to the combination of light and noise intensity. Data suggest that increments in sensory conditions may differentially activate the cerebral hemispheres of the elderly and younger groups affecting grip strength. Results are discussed in relation to the hemiaging hypothesis.
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PMID:Age differences in hemispheric activation to sensory condition. 900 85

The present study examined the relationship between hostility level and cerebral hemispheric motor functioning of 70 left-cerebral dominant men. Using the Cook-Medley Hostility Scale, the subject group was divided into thirds: One-third (N = 23) were classified as low-hostile, one-third (N = 23) were classified as high-hostile, and the remainder (N = 24) were excluded from analysis. A hand dynamometer was used to assess hand grip strength, perseveration, and fatigue, as measures of hemispheric motor functioning. Results yielded a hand-by-hostility group interaction, which indicated that high-hostile men evidenced significantly less hand grip strength at the right hand and significantly greater hand grip strength at the left hand relative to low-hostile men. These results suggest that high-hostile men may experience relatively greater right-cerebral arousal relative to their low-hostile counterparts. In other results, both groups showed greater perseveration at the left hand than at the right hand. Both groups also showed significant fatigue across trials at both hands. Analysis also revealed a hand-by-trial interaction, indicating that the right hand fatigued more quickly than the left hand across trials. Resistance to fatigue at the left hand and overestimation or relative imprecision in motor movement at the left hand are discussed in terms of arousal theory. These results and others are cited as contributing inroads into distinguishing between the emotional problems of depression, anxiety, and hostility.
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PMID:Asymmetry in hand grip strength and fatigue in low- and high-hostile men. 1232 95

We tested whether behavioural manifestations of mental fatigue may be linked to compromised executive control, which refers to the ability to regulate perceptual and motor processes for goal-directed behaviour. In complex tasks, compromised executive control may become manifest as decreased flexibility and sub-optimal planning. In the study we use the Wisconsin Card Sorting Test (WCST) and the Tower of London (TOL), which respectively measure flexibility (e.g., perseverative errors) and planning. A simple memory task was used as a control measure. Fatigue was induced through working for 2 h on cognitively demanding tasks. The results showed that compared to a non-fatigued group, fatigued participants displayed more perseveration on the WCST and showed prolonged planning time on the TOL. Fatigue did not affect performance on the simple memory task. These findings indicate compromised executive control under fatigue, which may explain the typical errors and sub-optimal performance that are often found in fatigued people.
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PMID:Mental fatigue and the control of cognitive processes: effects on perseveration and planning. 1267 43

Thirty young, unmedicated, outpatient, depressed women were compared to an equal number of matching controls on a series of neuropsychological tests purported to be sensitive to the executive functions. Specifically, the measures included the Design Fluency Test, Hand Dynamometer tasks of grip strength, perseveration, and fatigue, the FAS Verbal Fluency Test, the Stroop Color and Word Test, and the Trail Making Test (Parts A and B). Despite past research which has indicated anterior hemispheric asymmetries and impaired neurocognitive performances in depressives, this research failed to identify any reliable differences between depressed and nondepressed women on any of the neuropsychological measures. These results argue against the frequently held stereotype that depressed individuals typically display impaired performances on neurocognitive tasks. Furthermore, since the profile of the depressed sample appeared to differ significantly from past studies, a discussion is provided as to how the characteristics of this group may have impacted the results. Implications of these findings for clinical practice and future research are also provided.
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PMID:Neuropsychological test performances of young depressed outpatient women. An examination of executive functions. 1459 May 79

In order to react adequately to any new challenge, it is necessary to stop all ongoing activity. The first phase in the orienting response to a novel stimulus is an arrest of all ongoing activity. Inhibition is also necessary to switch from one behaviour to another, and from one cognitive activity to another. Inhibition was a difficult phenomenon to handle until the role of inhibitory synapses was demonstrated, and that many brain areas have an inhibitory function for overt behaviour and for establishing new responses in learning experiments. The role of these areas for learning and for plasticity of the brain has been well established. Recently, the role of inhibition, or lack of inhibition, for cognitive activities has been discussed for the understanding of somatization and sensitization to afferent somatic impulses. It has been postulated that muscle pain is maintained by positive feed back loops between muscles, the spinal cord, and the brain areas for pain and interpretation of pain. Activity in these loops may lead to sensitisation of the neural circuits, leading to chronic pain states. Similar models have been presented for non-specific gastric and intestinal complaints, and for fatigue and depression. Rumination and perseveration of negative thoughts may maintain the activity in these loops.
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PMID:Press stop to start: the role of inhibition for choice and health. 1596 45

Because of highly active antiretroviral therapy, people are now aging with HIV. Several stressors associated with aging with HIV may result in increased levels of depression and suicidal ideation. In addition, neurological and cognitive changes that often accompany both aging and HIV must be considered because those aging with HIV are at greater risk of developing such problems. These problems may be reflected in executive functioning deficits and initiation and perseveration difficulties. Adults experiencing such problems may be predisposed to ruminative thoughts that can impair the ability to effectively cope with the stressors associated with aging with HIV. Moreover, other conditions such as posttraumatic stress disorder, chronic drug use, and mitochondrial-damage-related fatigue can predispose these adults to the development of further neurological and cognitive problems. These problems may foster further ruminative thinking and increase the severity of depression and suicidal ideation. Implications for nursing practice, intervention, and research are provided.
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PMID:Suicidal ideation in adults aging with HIV: neurological and cognitive considerations. 1905 76

Deficits in cognitive functioning associated with shift work are particularly relevant to occupational performance; however, few studies have examined how cognitive functioning is associated with specific components of shift work. This observational study examined how circadian phase, nocturnal sleepiness, and daytime insomnia in a sample of shift workers ( N = 30) were associated with cognitive flexibility during the night shift. Cognitive flexibility was measured using a computerized task-switching paradigm, which produces 2 indexes of flexibility: switch cost and set inhibition. Switch cost represents the additional cognitive effort required in switching to a different task and can impact performance when multitasking is involved. Set inhibition is the efficiency in returning to previously completed tasks and represents the degree of cognitive perseveration, which can lead to reduced accuracy. Circadian phase was measured via melatonin assays, nocturnal sleepiness was assessed using the Multiple Sleep Latency Test, and daytime insomnia was assessed using the Insomnia Severity Index. Results indicated that those with an earlier circadian phase, insomnia, and sleepiness exhibited reduced cognitive flexibility; however, specific components of cognitive flexibility were differentially associated with circadian phase, insomnia, and sleepiness. Individuals with an earlier circadian phase (thus more misaligned to the night shift) exhibited larger switch costs, which was also associated with reduced task efficiency. Shift workers with more daytime insomnia demonstrated difficulties with cognitive inhibition, whereas nocturnal sleepiness was associated with difficulties in reactivating previous tasks. Deficits in set inhibition were also related to reduced accuracy and increased perseverative errors. Together, this study indicates that task performance deficits in shift work are complex and are variably impacted by different mechanisms. Future research may examine phenotypic differences in shift work and the associated consequences. Results also suggest that fatigue risk management strategies may benefit from increased scope and specificity in assessment of sleep, sleepiness, and circadian rhythms in shift workers.
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PMID:Shift Work and Cognitive Flexibility: Decomposing Task Performance. 2847 Jan 21


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