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PubMed1986

Lifetime and recent alcohol consumption among male alcoholics. Neuropsychological implications.

Alcoholics experience a relatively well-documented pattern of decline in cognitive and motor functions. This decline is likely the result of multiple causal factors that include head injury, malnutrition, and alcohol consumption. Although alcohol consumption per se has been considered a primary causal agent, research has not demonstrated a consistent relationship between levels of alcohol consumption and these neuropsychological deficits. This study explored such relationships within a sample of 40 detoxified male inpatient alcoholics who did not have a history of polydrug abuse, malnutrition, head injury, neurological disease, or non-alcohol-related psychiatric treatment. Increasing lifetime alcohol consumption was associated with increasing age-adjusted impairment on Halstead-Reitan tests that measure such aspects of functioning as concept formation, cognitive flexibility, and perceptual-motor abilities. Alcohol consumption had a linear relationship with test scores and hypothesized interactions with age did not emerge, nor did the effects of recent drinking appear dependent upon total lifetime consumption. The pattern of consumption (e.g., amount consumed per occasion, spree drinking) was also unrelated to impairment, and the critical neuropathological factor appeared to be the total amount of lifetime alcohol consumption.

Adult↗
PubMedDate not supplied

Serum cholesterol and cognitive performance in the Framingham Heart Study.

OBJECTIVE: The objective of this study was to examine the relationship between total cholesterol (TC) and cognitive performance within the context of the Framingham Heart Study, a large, community-based, prospective investigation of cardiovascular risk factors. METHODS: Participants were 789 men and 1105 women from the Framingham Heart Study original cohort who were free of dementia and stroke and who received biennial TC determinations over a 16- to 18-year surveillance period. Cognitive tests were administered 4 to 6 years subsequent to the surveillance period and consisted of measures of learning, memory, attention/concentration, abstract reasoning, concept formation, and organizational abilities. Statistical models were adjusted for multiple demographic and biological covariates. RESULTS: There was a significant positive linear association between TC and measures of verbal fluency, attention/concentration, abstract reasoning, and a composite score measuring multiple cognitive domains. Performance levels for three clinically defined groups were examined. Participants with "desirable" TC levels (<200 mg/dL) performed less well than participants with borderline-high TC levels (200-239 mg/dL) and participants with high TC levels (there exists 240 mg/dL). CONCLUSIONS: Lower naturally occurring TC levels are associated with poorer performance on cognitive measures, which place high demands on abstract reasoning, attention/concentration, word fluency, and executive functioning.

Cardiovascular Diseases↗
PubMed1998

Brain imaging of affective disorders and schizophrenia.

We review recent findings in human brain imaging, for example, which brain areas are used during perception of colors, moving objects, human faces, facial expressions, sadness and happiness etc. One study used fluorine-18-labeled deoxyglucose positron emission tomography (PET) in patients with unipolar depression and bipolar depression, and found hypometabolism in the left anterolateral prefrontal cortex. Another study reported increased regional cerebral blood flow in the amygdala in familial pure depressive disease. Using 11C-glucose PET, we reported that the glutamic acid pool was reduced in cortical areas of the brain in patients with major depression. We also found that the thalamic and cingulate areas were hyperactive in drug-naive (never medicated) acute schizophrenics, while the associative frontal, parietal, temporal gyri were hypoactive in drug-naive chronic schizophrenics. Brain biochemical disturbances of schizophrenic patients involved glutamic acid, N-acetyl aspartic acid, phosphatidylcholine and sphingomyelin which are important chemical substances in the working brain. The areas of the thalamus and the cingulate which become hyperactive in acute schizophrenic patients are important brain areas for perception and communication. The association areas of the cortex which become disturbed in chronic schizophrenia are essential brain areas in human creativity (language, concepts, formation of cultures and societies) and exist only in human beings.

Bipolar Disorder↗
PubMed2006

Exploring mental status in Friedreich's ataxia: a combined neuropsychological, behavioral and neuroimaging study.

Despite much evidence of cognitive and affective disorders in Friedreich's ataxia (FRDA), the nature of mental status in FRDA has received little systematic attention. It has been proposed that the cerebellum may interfere indirectly with cognition through the cerebello-cortical loops, whereas the role of pathological changes in different areas of the central nervous system is still undetermined. In the present study, 13 patients with molecularly determined FRDA and a group of matched controls were evaluated by a comprehensive battery of neuropsychological tests and the Minnesota Multiphasic Personality Inventory. A repetitive task of simple visual-reaction times was used to investigate implicit learning in all subjects. Pathological changes in cortical areas were explored comparing cerebral activations of patients and controls during finger movements (functional MRI). The intelligence profile of FRDA patients is characterized by concrete thinking, poor capacity in concept formation and visuospatial reasoning. FRDA patients show reduced speed of information processing. The learning effect seen in controls was notably absent in patients with FRDA. The patients' personality is characterized by some pathological aspects and reduced defensiveness. Patterns of cortical activation during finger movements are heterogeneous in patients compared to controls. Cognitive impairment, mood disorders and motor deficits in FRDA patients may be the result of the cumulative damage caused by frataxin deficiency not only in the cerebellum and spinal cord but also in other brain areas.

Adolescent↗
PubMed1992

Cognitive functioning, ASP, and family history of alcoholism in young men at risk for alcoholism.

Previous research has suggested that individuals with a family history of alcoholism may have cognitive deficits that predate, and possibly predispose, to the onset of alcoholism. However, these deficiencies may result from other factors, e.g., comorbid psychopathology. The current study investigated the neuropsychological functioning of young adult males at high risk for alcohol abuse due to a family history of alcoholism (FH) and/or a personal history of antisocial personality disorder (ASP). A family history of alcoholism (FH+) alone was not associated with neuropsychological impairment. Subjects with ASP, however, exhibited some difficulty with higher level motor control and with verbal concept formation compared with nonASP subjects. No clear pattern of FH x ASP interaction was evident in the measures examined. These findings suggest that previous findings suggesting cognitive deficiencies in FH+ individuals may have been related to a failure to consider co-morbid ASP. The deficits exhibited by the ASP subjects may reflect both reduced inhibitory control and a deficiency in higher level verbal skills. These deficiencies may leave ASP individuals less capable of utilizing higher level language skills to regulate behavior.

Adult↗
PubMed1965

OBSERVABLE CHANGES OF HYPOTHESES UNDER POSITIVE REINFORCEMENT.

In mathematical models of concept learning it has consistently been assumed that positive reinforcement cannot lead to a change of the hypothesis determining the overt response. When hypotheses are experimentally identified and recorded along with positive and negative reinforcements of stimulus-response pairs, it can be shown that hypotheses may change after a positive reinforcement. Positive reinforcement has an information content for subjects that has not yet been adequately recognized in concept formation studies.

Humans↗
PubMed1984

Benign familial chorea: an association with intellectual impairment.

Twenty-four members of a family with benign familial chorea underwent testing for evidence of intellectual impairment. Lower verbal intelligence was found in affected individuals compared to unaffected family members, as were deficits in verbal abstract concept formation. These results challenge the notion that benign familial chorea uniformly spares the intellect in all kindreds.

Adult↗
PubMed1990

Neuropsychological assessment in patients with relapsing-remitting multiple sclerosis and mild functional impairment: correlation with magnetic resonance imaging.

Forty one moderately impaired patients with clinically confirmed multiple sclerosis (MS) and a relapsing-remitting course were submitted to a neuropsychological battery and magnetic resonance imaging (MRI) to correlate the neuropsychological performances with the degree of cerebral demyelination. The neuropsychological results were indicative of a very mild overall impairment. The patients were subdivided into two groups (extensive periventricular demyelination or discrete lesions on MRI) and the results of neuropsychological tests compared. Patients with extensive periventricular demyelination had an inferior performance on concept formation, non-verbal reasoning and verbal memory tests.

Adolescent↗
PubMed1995

Neuropsychological impairments in chronic fatigue syndrome, multiple sclerosis, and depression.

To examine the degree and nature of cognitive impairments in chronic fatigue syndrome, a comprehensive neuropsychological battery was given to patients with chronic fatigue syndrome, multiple sclerosis, depressed patients, and healthy controls. The battery included tests of attention and concentration, information processing speed, verbal and visual memory, intellectual ability, and concept formation. Measures of depression and anxiety were also obtained. The chronic fatigue syndrome group did not differ from the depressed group in overall neuropsychological performance, but differed from the multiple sclerosis and control groups. The most significant impairment was in information processing speed in the chronic fatigue syndrome group. Depression and anxiety were not related to neuropsychological performance. The influence of reduced information processing on other areas of cognition is discussed.

Adult↗
PubMed1998

Dopa responsive dystonia with Turner's syndrome: clinical, genetic, and neuropsychological studies in a family with a new mutation in the GTP-cyclohydrolase I gene.

A 26 year old woman with dopa responsive dystonia and cytogenetically confirmed Turner's syndrome had bilateral globus pallidus hypointensity on brain MRI. Among the living members of a five generation pedigree the patient's mother and the mother's sister also had dopa responsive dystonia; a maternal grandfather had senile parkinsonism, his niece isolated postural tremor. No other family member had Turner's syndrome. A new missense mutation in exon I of the gene of GTP-cyclohydrolase I was found in the three family members with dopa responsive dystonia. With levodopa substitution the patients with dopa responsive dystonia improved clinically as well as in quantitative tests on hand tapping, verbal and performance IQ, concept formation, and set shifting abilities.

Adult↗
PubMed1984

Occupational lead neurotoxicity: a behavioural and electrophysiological evaluation. Study design and year one results.

To evaluate the effects of chronic lead exposure on the nervous system in adults, a set of neurobehavioural and electrophysiological tests was administered to 99 lead exposed foundry employees and 61 unexposed workers. Current and past blood lead concentrations were used to estimate the degree of lead absorption; all previous blood lead concentrations had been less than or equal to 90 micrograms/100 ml. Characteristic signs (such as wrist extensor weakness) or symptoms (such as colic) of lead poisoning were not seen. Sensory conduction in the sural nerve was not affected. By contrast, various neurobehavioural functions deteriorated with increasing lead burden. Workers with blood lead concentrations between 40 and 60 micrograms/100 ml showed impaired performance on tests of verbal concept formation, visual/motor performance, memory, and mood. Thus impairment in central nervous system function in lead exposed adults occurred in the absence of peripheral nervous system derangement and increased in severity with increasing lead dose.

Adolescent↗
PubMed1985

Occupational lead neurotoxicity: improvement in behavioural effects after reduction of exposure.

To evaluate critical exposure levels and the reversibility of lead neurotoxicity a group of lead exposed foundry workers and an unexposed reference population were followed up for three years. During this period, tests designed to monitor neurobehavioural function and lead dose were administered. Evaluations of 160 workers during the first year showed dose dependent decrements in mood, visual/motor performance, memory, and verbal concept formation. Subsequently, an improvement in the hygienic conditions at the plant resulted in striking reductions in blood lead concentrations over the following two years. Attendant improvement in indices of tension (20% reduction), anger (18%), depression (26%), fatigue (27%), and confusion (13%) was observed. Performance on neurobehavioural testing generally correlated best with integrated dose estimates derived from blood lead concentrations measured periodically over the study period; zinc protoporphyrin levels were less well correlated with function. This investigation confirms the importance of compliance with workplace standards designed to lower exposures to ensure that individual blood lead concentrations remain below 50 micrograms/dl.

Behavior↗
PubMed1992

Effect of instructional cues on schizophrenic patients' performance on the Wisconsin Card Sorting Test.

OBJECTIVE: Schizophrenic patients are particularly deficient on measures of executive functioning, notably the Wisconsin Card Sorting Test. This study was conducted to determine the efficacy of a cuing strategy in facilitating performance on this cognitive measure of the integrity of prefrontal brain structures and functioning. METHOD: Twenty-four schizophrenic inpatients and 24 demographically matched inpatients with mood disorders were administered the Wisconsin Card Sorting Test either with instructional cues at the beginning of the task or with the standard administration procedure. RESULTS: There was a significant benefit of cues for the patients with affective disorders as well as for the schizophrenic patients. The schizophrenic subjects in the uncued condition maintained poor but stable performance throughout the course of the task. CONCLUSIONS: The study suggests that the deficit in executive functioning of schizophrenic patients may lie in the formation of concepts, not in their application.

Adolescent↗
PubMed1989

Modeling the cognitive content of displays.

An approach for measuring the cognitive complexity of visual displays is discussed and applied to a dynamic display of avionic information. A semantic network formalism is used to model two interrelated knowledge systems, world knowledge and display knowledge. The information the operator receives during training about the general display format characteristics and the task requirements, along with other previously stored information, constitutes world knowledge. The semantic content of a particular configuration of information encountered during task performance constitutes display knowledge. Four orthogonal predictor measures of cognitive complexity were derived from the networks. In an experiment three of the orthogonal predictors were significantly correlated with task performance. After averaging across operators, the three significant predictors accounted for 99% of the variation of display effectiveness. Results indicate that a model of cognitive complexity based on a semantic network formalism may provide a useful technique for quantitatively evaluating the quality of competing display format concepts.

Adult↗
PubMedDate not supplied

Vowel categorization and the critical band.

Using the concept formation paradigm, two series of experiments were conducted to test the hypothesis that the critical band (CB) was a factor in learning to make absolute discriminations of vowels. The specific hypothesis being examined was that the CB is a psychoacoustic boundary in learning to make vowel categorizations, and that learning absolute discriminations of pairs of vowels that differ in one of their formants by one bark or more is significantly easier than learning absolute discriminations of vowels that differ by less than one bark. Subjects were given the task of learning to identify paired sets of synthesized vowels that differed in either F1 or F2 by 0.4, 0.6, 0.8, 1.0, or 1.2 bark. The results of these experiments suggest that the critical bandwidth is not a natural psychoacoustic boundary in the learning of vowel categories, and also that subjects seem better able to learn distinctions involving differences in F1 than distinctions involving differences in F2. The discussion raises the possibility that vowels that differ by less than one bark may not be perceptually viable because of such factors as ambient noise, articulatory constraints, and coarticulatory influences. Some evidence from Dutch and French is presented in support of this conjecture.

Auditory Perception↗
PubMed2000

Factor structure of the Reitan-Indiana Neuropsychological Battery for Children.

The Reitan-Indiana Neuropsychological Battery (RINB) was administered to a sample of children referred for educational and behavioral problems (N = 130). Subtest scores were standardized by age at 1-year intervals (6, 7, and 8 years). A principal components analysis (PCA) with promax rotation of 18 subtest scores produced a five-factor solution. Factor 1 emphasizes tactile/spatial functions, Factor 2 emphasizes concept formation and visual/spatial abilities, Factor 3 reflects motor strength, Factor 4 emphasizes sensory perception, and Factor 5 reflects motor speed. Principal factor analysis (PFA) of these data was performed to permit comparison with the PCA solutions. The PFA and PCA solutions were similar and major conclusions about factor structure were consistent.

Child↗
PubMed2005

The nature and frequency of cognitive deficits in children with neurofibromatosis type 1.

OBJECTIVE: To assess the frequency and severity of specific cognitive deficits in children with neurofibromatosis type 1 (NF1) in a large unbiased cohort. METHODS: Extensive cognitive assessments were performed in 81 children with NF1 ages 8 to 16 years and their performance was compared with that of 49 unaffected sibling controls. RESULTS: Eighty-one percent of the children with NF1 had moderate to severe impairment in one or more areas of cognitive functioning. Although 51% of children with NF1 performed poorly on tasks of reading, spelling, and mathematics, specific learning disabilities (as defined by IQ-achievement discrepancies) were present in only 20% of the children. Sustained attention difficulties were present in 63% of children with NF1, with 38% of children with NF1 fulfilling the diagnostic criteria for attention deficit-hyperactivity disorder. The NF1 neuropsychological profile is characterized by deficits in perceptual skills (visuospatial and visuoperceptual), executive functioning (planning and abstract concept formation), and attention (sustained and switching). Interestingly, both verbal and visual memory was unaffected in NF1 children, and their memory skills were in general stronger than their level of general intellectual function. Although both expressive and receptive language skills were significantly impaired in NF1 children, they appeared to be relatively better preserved than visuospatial abilities once IQ is taken into account. CONCLUSION: There is an extremely high frequency of cognitive problems in children with neurofibromatosis type 1, making cognitive dysfunction the most common complication to affect quality of life in these children.

Adolescent↗
PubMed1991

Mild cognitive impairment in the elderly: predictors of dementia.

We conducted full diagnostic evaluations, including a comprehensive cognitive assessment battery, of a group of 32 elderly subjects with a clinically identified mild cognitive impairment and a group of 32 age-matched and education-matched normal subjects. The mildly impaired subjects performed significantly more poorly than the controls on tests of recent memory, remote memory, language function, concept formation, and visuospatial praxis. Follow-up evaluations of cognitive status 2 years later revealed clinically detectable cognitive decline relative baseline in 23 (72%) of the mildly impaired subjects. Several of the objective psychological tests accurately discriminated at baseline between the decliners and nondecliners in the mildly impaired group. Among the 20 mildly impaired subjects with no complicating conditions, 16 exhibited cognitive deterioration between baseline and follow-up. These results suggest that most elderly subjects with mild cognitive deficits, as determined by clinical evaluation and objective psychological testing, will manifest the progressive mental deterioration characteristic of dementia and that psychometric predictors can be used to distinguish between benign and more significant underlying disorders in mildly impaired elderly subjects.

Aged↗