Speed Of Cognitive Performance Research Articles

Incremental rate of prefrontal oxygenation determines performance speed during cognitive Stroop test: the effect of ageing.

Cognitive function declines with age. The underlying mechanisms responsible for the deterioration of cognitive performance, however, remain poorly understood. We hypothesized that an incremental rate of prefrontal oxygenation during a cognitive Stroop test decreases in progress of ageing, resulting in a slowdown of cognitive performance. To test this hypothesis, we identified, using multichannel near-infrared spectroscopy, the characteristics of the oxygenated-hemoglobin concentration (Oxy-Hb) responses of the prefrontal cortex to both incongruent Stroop and congruent word-reading test. Spatial distributions of the significant changes in the three components (initial slope, peak amplitude, and area under the curve) of the Oxy-Hb response were compared between young and elderly subjects. The Stroop interference time (as a difference in total periods for executing Stroop and word-reading test, respectively) approximately doubled in elderly as compared to young subjects. The Oxy-Hb in the rostrolateral, but not caudal, prefrontal cortex increased during the Stroop test in both age groups. The initial slope of the Oxy-Hb response, rather than the peak and area under the curve, had a strong correlation with cognitive performance speed. Taken together, it is likely that the incremental rate of prefrontal oxygenation may decrease in progress of ageing, resulting in a decline in cognitive performance.

Effects of Intermittent Hypoxia on Cognitive Performance and Quality of Life in Elderly Adults: A Pilot Study

Background: Physical exercise has a positive effect on cognitive performance and quality of life (QoL). One reason for this is the upregulation of brain-derived neurotrophic factor, which improves brain plasticity. Intermittent hypoxia promotes first the proliferation of endogenous neuroprogenitors which leads to an increased number of newborn neurons and second the expression of brain-derived neurotrophic factor in the adult hippocampus. Intermittent hypoxia may, therefore, support synaptic plasticity, the process of learning and provoke antidepressant-like effects. Hence, intermittent hypoxia might also lead to improved cognitive functioning and QoL. Objective: This study aims to evaluate to what extent physical activity with preceded intermittent hypoxic training is more effective than solely strength-endurance training on cognitive performance and QoL. Methods: 34 retired people aged between 60 and 70 years were randomly assigned to a control group or intervention group. Contrarily to the control group, which was supplied with a placebo air mixture, the intervention group was supplied with an intermittent hypoxic training prior to a strength-endurance exercise program. The cognitive performance of individuals was examined using the d2 test and the Number Combination Test (ZVT) both before and after the exercise program. We assessed QoL with the Medical Outcomes Study Short-Form 36-Item Health Survey (SF-12) and Pittsburgh Sleep Quality Index (PSQI) and the strength-endurance capacity using the Spring test. Results: Regarding the d2 test, a time × group effect was observed. Speed of cognitive performance in seconds was measured using ZVT. Here, no interaction effect was discovered. An interaction effect was not found in the Physical Component Summary scores (SF-12). Regarding the Mental Component Summary, an interaction effect just failed to become statistically significant. Furthermore, we determined sleep quality with the PSQI. Here, an interaction effect was observed. The analysis of the strength-endurance test revealed no interaction effects. Conclusion: The data of the current study suggest that an additional intermittent hypoxic training combined with physical exercise augments the positive effects of exercise on cognitive performance and QoL in elderly humans.

Simulated Cataract and Low Contrast Stimuli Impair Cognitive Performance in Older Adults: Implications for Neuropsychological Assessment and Everyday Function

ABSTRACT Objective: To investigate how age-related declines in vision (particularly contrast sensitivity), simulated using cataract-goggles and low-contrast stimuli, influence the accuracy and speed of cognitive test performance in older adults. An additional aim was to investigate whether declines in vision differentially affect secondary more than primary memory. Method: Using a fully within-subjects design, 50 older drivers aged 66–87 years completed two tests of cognitive performance – letter matching (perceptual speed) and symbol recall (short-term memory) – under different viewing conditions that degraded visual input (low-contrast stimuli, cataract-goggles, and low-contrast stimuli combined with cataract-goggles, compared with normal viewing). However, presentation time was also manipulated for letter matching. Visual function, as measured using standard charts, was taken into account in statistical analyses. Results: Accuracy and speed for cognitive tasks were significantly impaired when visual input was degraded. Furthermore, cognitive performance was positively associated with contrast sensitivity. Presentation time did not influence cognitive performance, and visual gradation did not differentially influence primary and secondary memory. Conclusion: Age-related declines in visual function can impact on the accuracy and speed of cognitive performance, and therefore the cognitive abilities of older adults may be underestimated in neuropsychological testing. It is thus critical that visual function be assessed prior to testing, and that stimuli be adapted to older adults' sensory capabilities (e.g., by maximising stimuli contrast).

Alcohol-impaired speed and accuracy of cognitive functions: A review of acute tolerance and recovery of cognitive performance.

Much research on the effects of a dose of alcohol has shown that motor skills recover from impairment as blood alcohol concentrations (BACs) decline and that acute tolerance to alcohol impairment can develop during the course of the dose. Comparable alcohol research on cognitive performance is sparse but has increased with the development of computerized cognitive tasks. This article reviews the results of recent research using these tasks to test the development of acute tolerance in cognitive performance and recovery from impairment during declining BACs. Results show that speed and accuracy do not necessarily agree in detecting cognitive impairment, and this mismatch most frequently occurs during declining BACs. Speed of cognitive performance usually recovers from impairment to drug-free levels during declining BACs, whereas alcohol-increased errors fail to diminish. As a consequence, speed of cognitive processing tends to develop acute tolerance, but no such tendency is shown in accuracy. This "acute protracted error" phenomenon has not previously been documented. The findings pose a challenge to the theory of alcohol tolerance on the basis of physiological adaptation and raise new research questions concerning the independence of speed and accuracy of cognitive processes, as well as hemispheric lateralization of alcohol effects. The occurrence of alcohol-induced protracted cognitive errors long after speed returned to normal is identified as a potential threat to the safety of social drinkers that requires urgent investigation.

The COGNITION Study Rationale and Design: Influence of Closed Loop Stimulation on Cognitive Performance in Pacemaker Patients

Several studies showed the beneficial effect of pacemaker implantation on cognitive performance in patients with bradycardia. But it has never been investigated if patients with chronotropic incompetence may improve their cognitive performance if treated by a rate-adaptive system reacting to mental stress in comparison to the most frequently used accelerometer-driven pacing. The randomized, single-blind, multicenter COGNITION study evaluates if closed loop stimulation (CLS) offers incremental benefit in the speed of cognitive performance and the overall well-being of elderly patients with bradycardia compared with accelerometer-based pacing. Four hundred chronotropically incompetent patients older than 55 years will be randomized 3-6 weeks after implantation to CLS or accelerometer sensor. Follow-up visits are performed after 12 and 24 months. The speed of cognitive performance, which is the underlying function influencing all other aspects of cognitive performance, will be assessed by the number connection test, a standardized psychometric test for the elderly. Secondary endpoints include patient self-assessment of different aspects of health (by visual analogue scales), quality of life (by SF-8 health survey), the incidence of atrial fibrillation (episodes lasting for longer than 24 hours), and the frequency of serious adverse events. In the ongoing COGNITION study, we aim at long-term comparison of two rate-adaptive systems, focusing on the cognitive performance of the patients, which was neglected in the past evaluation of pacemaker sensors.

Unterscheiden sich die Effekte stationärer arbeits- und ergotherapeutischer Maßnahmen? - Ergebnisse einer kontrollierten Multizenterstudie des Kompetenznetzes Schizophrenie

For some decades, vocational therapy approaches have been an integral part of inpatient psychiatric treatment of patients with schizophrenia. Like most sociotherapeutic measures, they are largely hypothesis-based. So far, their effectiveness has been subjected to very little scientific scrutiny. The results of a multicenter study in which five vocational therapy models were compared with creativity-oriented ergotherapy in a prospective, randomized control group design are presented. Target criteria were job-relevant skills, psychopathology, general level of functioning, quality of life, self-efficacy, and speed of cognitive performance. 227 patients were enrolled in the study, which was carried out within the framework of the German Research Network on Schizophrenia funded by the German Federal Ministry for Education and Research (BMBF). Multicenter analyses in a pre-post comparison revealed only minimum differences between the experimental and the control group over a four-week intervention period. Job-oriented approaches cannot currently be assumed to be superior to creativity-oriented ergotherapy.

The Effects of a Single Dose of Pemoline on Performance and Mood During Sleep Deprivation

Stimulants may be used to improve performance during sleep deprivation. A previous study found that multiple doses of pemoline (37.5 mg every 12 hr) during 64 hr of sleep deprivation improved speed of cognitive performance with variable effects on accuracy. In this study, a single dose of 37.5 mg of pemoline was administered once during the 2nd of 2 nights of sleep deprivation. With this administration schedule, participants showed improved performance, predominantly on accuracy (percentage correct) measures. Effects on speed were minimal. The three tasks which were primarily tests of reaction time showed no stimulant effects. Pemoline had no negative effects on performance, in contrast to the findings of the multiple-dose study. Administration at the time of maximum need (previous sleep deprivation added to the effects of the circadian low period for performance and alertness) may explain the change in effects.