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Perceptual Speed (perceptual + speed)
Selected AbstractsEffects of lorazepam on visual perceptual abilitiesHUMAN PSYCHOPHARMACOLOGY: CLINICAL AND EXPERIMENTAL, Issue 3 2008S. Pompéia Abstract Objective To evaluate the effects of an acute dose of the benzodiazepine (BZ) lorazepam in young healthy volunteers on five distinguishable visual perception abilities determined by previous factor-analytic studies. Methods This was a double-blind, cross-over design study of acute oral doses of lorazepam (2,mg) and placebo in young healthy volunteers. We focused on a set of paper-and-pencil tests of visual perceptual abilities that load on five correlated but distinguishable factors (Spatial Visualization, Spatial Relations, Perceptual Speed, Closure Speed, and Closure Flexibility). Some other tests (DSST, immediate and delayed recall of prose; measures of subjective mood alterations) were used to control for the classic BZ-induced effects. Results Lorazepam impaired performance in the DSST and delayed recall of prose, increased subjective sedation and impaired tasks of all abilities except Spatial Visualization and Closure Speed. Only impairment in Perceptual Speed (Identical Pictures task) and delayed recall of prose were not explained by sedation. Conclusion Acute administration of lorazepam, in a dose that impaired episodic memory, selectively affected different visual perceptual abilities before and after controlling for sedation. Central executive demands and sedation did not account for results, so impairment in the Identical Pictures task may be attributed to lorazepam's visual processing alterations. Copyright © 2008 John Wiley & Sons, Ltd. [source] From language to reading and dyslexia,DYSLEXIA, Issue 1 2001Margaret J. Snowling Abstract This paper reviews evidence in support of the phonological deficit hypothesis of dyslexia. Findings from two experimental studies suggest that the phonological deficits of dyslexic children and adults cannot be explained in terms of impairments in low-level auditory mechanisms, but reflect higher-level language weaknesses. A study of individual differences in the pattern of reading skills in dyslexic children rejects the notion of ,sub-types'. Instead, the findings suggest that the variation seen in reading processes can be accounted for by differences in the severity of individual children's phonological deficits, modified by compensatory factors including visual memory, perceptual speed and print exposure. Children at genetic risk who go on to be dyslexic come to the task of reading with poorly specified phonological representations in the context of a more general delay in oral language development. Their prognosis (and that of their unaffected siblings) depends upon the balance of strengths and difficulties they show, with better language skills being a protective factor. Taken together, these findings suggest that current challenges to the phonological deficit theory can be met. Copyright © 2001 John Wiley & Sons, Ltd. [source] Assessing mild cognitive impairment among older African AmericansINTERNATIONAL JOURNAL OF GERIATRIC PSYCHIATRY, Issue 7 2010Alyssa A. Gamaldo Abstract Objectives To examine the frequency of Mild Cognitive Impairment (MCI) in African American older adults. The study also plans to explore the specific cognitive domains of impairment as well as whether there are differences in demographics, health, and cognitive performance between MCI and normal participants. Design Cross-sectional. Setting Independent-living sample of urban dwelling elders in Baltimore, Maryland. Participants The sample consisted of 554 subjects ranging in age from 50 to 95 (Mean,=,68.79,±,9.60). Measurements Socio-demographics and health were assessed. Several cognitive measures were administered to assess inductive reasoning, declarative memory, perceptual speed, working memory, executive functioning, language and global cognitive functioning. Results Approximately 22% of participants were considered MCI (i.e. 18% non-amnestic vs. 4% amnestic). A majority of the non-amnestic MCI participants had impairment in one cognitive domain, particularly language and executive function. Individuals classified as non-amnestic MCI were significantly older and had more years of education than normal individuals. The MCI groups were not significantly different than cognitively normal individuals on health factors. Individuals classified as MCI performed significantly worse on global cognitive measures as well as across specific cognitive domains than cognitively normal individuals. Conclusion This study demonstrates that impairment in a non-memory domain may be an early indicator of cognitive impairment, particularly among African Americans. Copyright © 2010 John Wiley & Sons, Ltd. [source] Two-Step Testing in Employee Selection: Is score inflation a problem?INTERNATIONAL JOURNAL OF SELECTION AND ASSESSMENT, Issue 2 2008Christopher D. Nye Unproctored Internet testing in employee selection has become increasingly popular over the past few years. However, there is a concern that cheating during unproctored administrations may influence the test results in terms of score inflation. The current research attempts to determine the extent of cheating on an unproctored Internet test of perceptual speed by analyzing data from a parallel version of the test administered in a proctored setting. Among a sample of 856 job applicants from nine European countries, there was no evidence that cheating occurred. In fact, evidence of an effect operating in the opposite direction was obtained. These results indicate that the use of unproctored Internet testing is appropriate for this type of test. [source] Serum Lipid Levels and Cognitive Change in Late LifeJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 3 2010Chandra A. Reynolds PhD OBJECTIVES: To assess the effect of lipids and lipoproteins on longitudinal cognitive performance and cognitive health in late life and to consider moderating factors such as age and sex that may clarify conflicting prior evidence. DESIGN: Prospective cohort study. SETTING: A 16-year longitudinal study of health and cognitive aging. PARTICIPANTS: Eight hundred nineteen adults from the Swedish Adoption Twin Study of Aging aged 50 and older at first cognitive testing, including 21 twin pairs discordant for dementia. MEASUREMENTS: Up to five occasions of cognitive measurements encompassing verbal, spatial, memory, and perceptual speed domains across a 16-year span; baseline serum lipids and lipoproteins including high-density lipoprotein cholesterol (HDL-C), apolipoprotein (apo)A1, apoB, total serum cholesterol, and triglycerides. RESULTS: The effect of lipids on cognitive change was most evident before age 65. In women, higher HDL-C and lower apoB and triglycerides predicted better maintenance of cognitive abilities, particularly verbal ability and perceptual speed, than age. Lipid values were less predictive of cognitive trajectories in men and, where observed, were in the contrary direction (i.e., higher total cholesterol and apoB values predicted better perceptual speed performance though faster rates of decline). In twin pairs discordant for dementia, higher total cholesterol and apoB levels were observed in the twin who subsequently developed dementia. CONCLUSION: High lipid levels may constitute a more important risk factor for cognitive health before age 65 than after. Findings for women are consistent with clinical recommendations, whereas for men, the findings correspond with earlier age-associated shifts in lipid profiles and the importance of lipid homeostasis to cognitive health. [source] | ||||||||||