Various Domains Of Cognitive Function Research Articles

White matter integrity in right hemisphere predicts pitch-related grammar learning

White matter plays an important role in various domains of cognitive function. While disruptions in white matter are known to affect many domains of behavior and cognition, the ability to acquire grammatical regularities has been mostly linked to the left hemisphere, perhaps due to its dependence on linguistic stimuli. The role of white matter in the right hemisphere in grammar acquisition is yet unknown. Here we show for the first time that in the domain of pitch, intact white matter connectivity in right-hemisphere analogs of language areas is important for grammar learning. A pitch-based artificial grammar learning task was conducted on subjects who also underwent diffusion tensor imaging. Probabilistic tractography using seed regions of interest in the right inferior frontal gyrus and right middle temporal gyrus showed positive correlations between tract volume and learning performance. Furthermore, significant correlations were observed between learning performance and FA in white matter underlying the supramarginal gyrus, corresponding to the right temporal–parietal junction of the arcuate fasciculus. The control task of recognition did not correlate with tract volume or FA, and control tracts in the left hemisphere did not correlate with behavioral performance. Results show that the right ventral arcuate fasciculus is important in pitch-based artificial grammar learning, and that brain structures subserving learning may be tied to the hemisphere that processes the stimulus more generally.

Thalamo-Basal Ganglia Connectivity in Postmenopausal Women Receiving Estrogen Therapy

Cumulative data on the effects of estrogen therapy (ET) on brain function in postmenopausal women suggests that ET influences cerebral metabolism and may protect against age-related declines in various domains of cognitive function. The beneficial cognitive effects of ET may relate to its modulation of the thalamic-striatum cholinergic and dopaminergic systems, as the activity of both neurotransmitter systems in the thalamus appears to be positively influenced by estrogen. In the current study, we attempted to evaluated regional cerebral brain metabolism utilizing [18F]-fluorodeoxyglucose positron emission tomography in 11 healthy recently-postmenopausal women on ET (ET+) in comparison to 11 recently-postmenopausal and ET-naïve women (ET-) in order to assess the effects of ET on cholinergic and dopaminergic system regulation. Results showed thalamo-basal ganglia connectivity among ET+ women but not among ET- women. The presence of connectivity in the thalamo-striatal pathway in recently postmenopausal women suggests estrogen effects in preserving integrity of the cholinergic and dopaminergic systems. The results also suggest that ET initiated at or near the menopausal transition may modulate brain aging by mediating complex sensory-motor functions.

Effects of amisulpride on the cognitive function of patients with schizophrenia who switched from risperidone

Objectives. The aims of this 13-week study were to examine the efficacy and safety of amisulpride, and effects on cognitive function in patients with schizophrenia after they switched from risperidone. Methods. Twenty-three patients with schizophrenia whose antipsychotic was switched from risperidone to amisulpride were recruited. The efficacy, safety, and cognitive function were assessed. Results. Significant improvements were noted in the PANSS, CGI-S, and MADRS. The prolactin level, but not any of the remaining laboratory variables, increased significantly. The cognitive function improved significantly, particularly in memory subtests. Conclusions. Switching antipsychotic from risperidone to amisulpride in schizophrenia might have significantly improved not only the efficacy, but also various domains of cognitive function. However, hyperprolactinemia existed and was sometimes even worse.

A Meta-Analysis of the Sensitivity of Various Neuropsychological Tests Used to Detect Chemotherapy-Induced Cognitive Impairment in Patients With Breast Cancer

To identify which neuropsychological tests have been used to evaluate chemotherapy-induced impairment in various domains of cognitive function in patients with breast cancer and to determine the sensitivity of each of the tests through estimation of effect size. Original studies published from 1966-June 2006. Although an array of neuropsychological tests are available to measure the various domains of cognitive function, information is lacking regarding the sensitivity and specificity of the tests to detect changes in cognitive function from chemotherapy. This meta-analysis provides initial data on the sensitivity of some neuropsychological tests to determine chemotherapy-induced changes in cognitive function in patients with breast cancer. The identification of sensitive neuro-psychological tests is crucial to further understanding of chemotherapy-induced cognitive impairments.

Chemotherapy may have small to moderate negative effects on cognitive functioning: Abstracted from: Jansen CE, Miaskowski C, Dodd M, Dowling G, Kramer J. A meta-analysis of studies of the effects of cancer chemotherapy on various domains of cognitive function. Cancer 2005; 104:2222–33.

Chemotherapy may have small to moderate negative effects on cognitive functioning: Abstracted from: Jansen CE, Miaskowski C, Dodd M, Dowling G, Kramer J. A meta-analysis of studies of the effects of cancer chemotherapy on various domains of cognitive function. Cancer 2005; 104:2222–33.

A metaanalysis of studies of the effects of cancer chemotherapy on various domains of cognitive function

Little is known about the effects of chemotherapy on cognitive function. The purposes of this metaanalysis were to estimate the effect sizes for the effect of chemotherapy on each domain of cognitive function and to differentiate effect sizes by each method of comparison of effects (i.e., normative data, control group, or baseline data). Sixteen studies that evaluated cognitive function in chemotherapy patients were included in the study. DSTAT metaanalysis software was used to calculate an effect size and confidence intervals for each neuropsychologic test. Tests were assigned to a specific cognitive domain, and an average effect size was determined for each domain. Only one domain of cognitive function (i.e., visual memory) had significant chemotherapy-induced impairment across all comparison types. However, when the neuropsychologic test scores of chemotherapy patients were compared with normative data, significant effect sizes were found for four domains of cognitive function (i.e., executive function, information processing speed, verbal memory, visual memory). In addition, significant, albeit small, effect sizes were found for language and verbal memory when chemotherapy patients' test scores were compared with test scores of healthy matched controls. All significant averaged effect sizes were in the negative direction, indicating that mean scores on neuropsychologic tests for patients who had received chemotherapy were on average lower than comparison scores. Data from this metaanalysis supported the hypothesis that chemotherapy can have a negative impact on cognitive function. However, most deficits in this study ranged from small to moderate and were nonsignificant.

The California Verbal Learning Test-Children's Version: Relation to Factor Indices of the Wechsler Intelligence Scale for Children-Third Edition

The California Verbal Learning Test-Children's Version (CVLT-C) provides clinicians with a method of assessing various aspects of children's verbal memory and has been found to be sensitive to memory deficits resulting from a variety of neurological conditions. Intuitively, the CVLT-C would be expected to be highly related to a child's verbal cognitive abilities; however, with only a few exceptions, the relationship of this test to various domains of cognitive function has not been broadly studied empirically. To examine this issue, we evaluated the amount of unique variance in CVLT-C scores that could be predicted by the Verbal Comprehension, Perceptual Organization, Freedom from Distractibility, and Processing Speed indices of the Wechsler Intelligence Scale for Children, Third Edition (WISC-III) beyond that accounted for by age and gender in a sample of 62 children referred to an outpatient psychiatry clinic for neuropsychological evaluation. While the Processing Speed Index predicted a significant amount of variance for both short and long delay free and cued recall, the Verbal Comprehension Index was a poor predictor of CVLT-C performance on all outcome variables, accounting for only 1.5 to 4.5% additional variance above age and gender. These findings indicate that while the CVLT-C may be relatively independent of influences of verbal intelligence and abstract verbal reasoning, general speed and efficiency of processing play an important role in successful encoding for later retrieval on the CVLT-C.

Acute hypoglycemia impairs nonverbal intelligence: importance of avoiding ceiling effects in cognitive function testing.

Acute hypoglycemia causes a progressive, reversible deterioration in cognitive function that becomes detectable at blood glucose concentrations below ∼3.0–3.4 mmol/l (1). In an earlier study in nondiabetic subjects, we reported that several facets of attention deteriorated significantly at an arterialized blood glucose level of 2.6 mmol/l (2). However, performance on Raven’s Progressive Matrices (RPM) was not significantly impaired at either 20 min or completion of the test (with no time limit). This was unexpected, because, previously, various domains of cognitive function had consistently been impaired at this level of hypoglycemia (1). Additionally, the RPM is acknowledged as being among the best indicators of general fluid intelligence (3) and has a substantial correlation with working memory (4), which is exquisitely sensitive to hypoglycemia (5). Hypoglycemia disrupts performance on different cognitive function tests to a variable degree, leading to speculation that different mental functions vary …

Cognitive function in euthymic Bipolar I Disorder

Recent reports have suggested the presence of persistent cognitive impairments in patients diagnosed with Bipolar Disorder even after prolonged euthymic phases. In this work, various domains of cognitive function were examined in asymptomatic patients diagnosed with Bipolar I Disorder (BDI) in comparison with healthy subjects. Fifteen otherwise healthy BDI patients with a prior history of psychosis during mania completed a neuropsychological testing battery after a prolonged asymptomatic remission. Their scores were compared to those of individually matched healthy subjects with unpaired two-tailed t-tests at P<0.01. Relationships between cognitive performance measures and clinical variables related to illness severity were also examined with Pearson correlations, P<0.05. We detected poorer performance on measures of verbal learning, executive functioning and motor coordination in BDI patients compared to control volunteers. Scores on tests of executive functioning were negatively correlated with the number of episodes of mania and depression. Social and occupational scores were also associated with a poorer performance on measures of verbal learning and executive function. Euthymic BDI patients, therefore, demonstrate reductions in specific cognitive domains even after prolonged asymptomatic phases. Some of these deficits appear to be associated with a more severe course of illness and poorer social and occupational functioning.