Claudia Voelcker-Rehage

Acute coordinative exercise improves attentional performance in adolescents.

Teachers complain about growing concentration deficits and reduced attention in adolescents. Exercise has been shown to positively affect cognitive performance. Due to the neuronal connection between the cerebellum and the frontal cortex, we hypothesized that cognitive performance might be influenced by bilateral coordinative exercise (CE) and that its effect on cognition might be already visible after short bouts of exercise. One hundred and fifteen healthy adolescents aged 13-16 years of an elite performance school were randomly assigned to an experimental and a control group and tested using the d2-test, a test of attention and concentration. Both groups performed the d2-test after a regular school lesson (pre-test), after 10 min of coordinative exercise and of a normal sport lesson (NSL, control group), respectively (post-test). Exercise was controlled for heart rate (HR). CE and NSL enhanced the d2-test performance from pre- to post-test significantly. ANOVA revealed a significant group (CE, NSL) by performance interaction in the d2-test indicating a higher improvement of CE as compared to NSL. HR was not significantly different between the groups. CE was more effective in completing the concentration and attention task. With the HR being the same in both groups we assume that the coordinative character of the exercise might be responsible for the significant differences. CE might lead to a pre-activation of parts of the brain which are also responsible for mediating functions like attention. Thus, our results support the request for more acute CE in schools, even in elite performance schools.

Cardiovascular and Coordination Training Differentially Improve Cognitive Performance and Neural Processing in Older Adults

Recent studies revealed a positive influence of physical activity on cognitive functioning in older adults. Studies that investigate the behavioral and neurophysiological effects of type and long term duration of physical training, however, are missing. We performed a 12-month longitudinal study to investigate the effects of cardiovascular and coordination training (control group: relaxation and stretching) on cognitive functions (executive control and perceptual speed) in older adults. We analyzed data of 44 participants aged 62–79 years. Participants were trained three times a week for 12 months. Their physical and cognitive performance was tested prior to training, and after 6 and 12 months. Changes in brain activation patterns were investigated using functional MRI. On the behavioral level, both experimental groups improved in executive functioning and perceptual speed but with differential effects on speed and accuracy. In line with the behavioral findings, neurophysiological results for executive control also revealed changes (increases and reductions) in brain activity for both interventions in frontal, parietal, and sensorimotor cortical areas. In contrast to the behavioral findings, neurophysiological changes were linear without indication of a plateau. In both intervention groups, prefrontal areas showed decreased activation after 6 and 12 months when performing an executive control task, as compared to the control group, indicating more efficient information processing. Furthermore, cardiovascular training was associated with an increased activation of the sensorimotor network, whereas coordination training was associated with increased activation in the visual–spatial network. Our data suggest that besides cardiovascular training also other types of physical activity improve cognition of older adults. The mechanisms, however, that underlie the performance changes seem to differ depending on the intervention.

Reversing cognitive–motor impairments in Parkinson’s disease patients using a computational modelling approach to deep brain stimulation programming

Deep brain stimulation in the subthalamic nucleus is an effective and safe surgical procedure that has been shown to reduce the motor dysfunction of patients with advanced Parkinsons disease. Bilateral subthalamic nucleus deep brain stimulation, however, has been associated with declines in cognitive and cognitive-motor functioning. It has been hypothesized that spread of current to nonmotor areas of the subthalamic nucleus may be responsible for declines in cognitive and cognitive-motor functioning. The aim of this study was to assess the cognitive-motor performance in advanced Parkinsons disease patients with subthalamic nucleus deep brain stimulation parameters determined clinically (Clinical) to settings derived from a patient-specific computational model (Model). Data were collected from 10 patients with advanced Parkinsons disease bilaterally implanted with subthalamic nucleus deep brain stimulation systems. These patients were assessed off medication and under three deep brain stimulation conditions: Off, Clinical or Model based stimulation. Clinical stimulation parameters had been determined based on clinical evaluations and were stable for at least 6 months prior to study participation. Model-based parameters were selected to minimize the spread of current to nonmotor portions of the subthalamic nucleus using Cicerone Deep Brain Stimulation software. For each stimulation condition, participants performed a working memory (n-back task) and motor task (force tracking) under single- and dual-task settings. During the dual-task, participants performed the n-back and force-tracking tasks simultaneously. Clinical and Model parameters were equally effective in improving the Unified Parkinsons disease Rating Scale III scores relative to Off deep brain stimulation scores. Single-task working memory declines, in the 2-back condition, were significantly less under Model compared with Clinical deep brain stimulation settings. Under dual-task conditions, force tracking was significantly better with Model compared with Clinical deep brain stimulation. In addition to better overall cognitive-motor performance associated with Model parameters, the amount of power consumed was on average less than half that used with the Clinical settings. These results indicate that the cognitive and cognitive-motor declines associated with bilateral subthalamic nucleus deep brain stimulation may be reversed, without compromising motor benefits, by using model-based stimulation parameters that minimize current spread into nonmotor regions of the subthalamic nucleus.

Physical and motor fitness are both related to cognition in old age

The benefits of fitness for cognitive performance in healthy older adults have repeatedly been demonstrated. Animal studies, however, have revealed differential relationships between physical and motor fitness and brain metabolism. We therefore investigated whether for older humans different dimensions of fitness are differentially associated with cognitive performance and brain activation patterns. Seventy‐two participants (mean age 68.99 years, SD = 3.66; 52 females) completed four psychometric tests reflecting two primary abilities of higher cognitive functioning (executive control, perceptual speed) and a battery of fitness tests comprising two fitness dimensions (physical and motor fitness). We found that not only physical fitness indexed by cardiovascular fitness and muscular strength, but also motor fitness including movement speed, balance, motor coordination and flexibility showed a strong association with cognitive functioning. Additionally, functional brain imaging data revealed that physical and motor fitness were differentially related to cognitive processes. Results are discussed with regard to the compensation hypothesis and potential consequences for intervention work.

Structural and functional brain changes related to different types of physical activity across the life span.

Physical activity has been shown to improve cognitive functioning. Research has largely focused on cognitive facilitation by cardiovascular exercise in older adults. Only few studies have investigated younger age groups or other types of physical activity. In this paper we review and summarize common results found in recent studies of metabolic (i.e. cardiovascular and resistance) and coordinative exercise. Findings from human motor learning are utilized to complement results on coordinative exercise. Results show that both types of exercise affect the brain differently. We propose possible mechanisms by which physical activity facilitates cognitive performance by briefly reviewing microscopic structural changes in animal research. Lastly, we highlight open research questions.

Bilateral subthalamic stimulation impairs cognitive ^motor performance in Parkinson's disease patients

Deep brain stimulation (DBS) is a surgical procedure that has been shown effective in improving the cardinal motor signs of advanced Parkinsons disease, however, declines in cognitive function have been associated with bilateral subthalamic nucleus (STN) DBS. Despite the fact that most activities of daily living clearly have motor and cognitive components performed simultaneously, postoperative assessments of cognitive and motor function occur, in general, in isolation of one another. The primary aim of this study was to determine the effects of unilateral and bilateral STN DBS on upper extremity motor function and cognitive performance under single- and dual-task conditions in advanced Parkinsons disease patients. Data were collected from eight advanced Parkinsons disease patients between the ages of 48 and 70 years (mean 56.5) who had bilaterally placed STN stimulators. Stimulation parameters for DBS devices were optimized clinically and were stable for at least 6 months prior to study participation. Data were collected while patients were Off anti-parkinsonian medications under three stimulation conditions: Off stimulation, unilateral DBS and bilateral DBS. In each stimulation condition patients performed a cognitive (n-back task) and motor (force tracking) task under single- and dual-task conditions. During dual-task conditions, patients performed the n-back and force-maintenance task simultaneously. Under relatively simple dual-task conditions there were no differences in cognitive or motor performance under unilateral and bilateral stimulation. As dual-task complexity increased, cognitive and motor performance was significantly worse with bilateral compared with unilateral stimulation. In the most complex dual-task condition (i.e. 2-back + force tracking), bilateral stimulation resulted in a level of motor performance that was similar to the Off stimulation condition. Significant declines in cognitive and motor function under modest dual-task conditions with bilateral but not with unilateral STN DBS suggest that unilateral procedures may be an alternative to bilateral DBS for some patients, in particular, those with asymmetric symptomology. From a clinical perspective, these results underscore the need to assess cognitive and motor function simultaneously during DBS programming as these conditions may better reflect the context in which daily activities are performed.

Motor-skill learning in older adults—a review of studies on age-related differences

This paper reviews research on motor-skill learning across the life span with particular emphasis on older age. For this purpose, studies that focus on age-related differences in fine and gross motor skills and studies that analyze the further refinement of known skills as well as learning of unknown motor skills are summarized. The reviewed studies suggest that although motor performance tends to decline in old age, learning capabilities remain intact, and older adults are able to achieve considerable performance gains. The extent to which the learning capability varies with age, however, has to be considered very carefully. While most studies revealed that performance gains in fine motor tasks are diminished in older adults, results for gross-motor-skill learning are more contradictory. Additionally, there is considerable agreement on the finding that age-related learning differences are statistically more robust in complex tasks, whereas in low-complexity tasks, the learning of younger and older adults is very similar. This applies to fine and gross motor skills. Relative age differences seem to become enlarged when effortful resources are required for motor performance. Thus, the decline in motor learning that accompanies aging is task specific and not absolute.

Not only cardiovascular, but also coordinative exercise increases hippocampal volume in older adults.

Cardiovascular activity has been shown to be positively associated with gray and white matter volume of, amongst others, frontal and temporal brain regions in older adults. This is particularly true for the hippocampus, a brain structure that plays an important role in learning and memory, and whose decline has been related to the development of Alzheimer’s disease. In the current study, we were interested in whether not only cardiovascular activity but also other types of physical activity, i.e., coordination training, were also positively associated with the volume of the hippocampus in older adults. For this purpose we first collected cross-sectional data on “metabolic fitness” (cardiovascular fitness and muscular strength) and “motor fitness” (e.g., balance, movement speed, fine coordination). Second, we performed a 12-month randomized controlled trial. Results revealed that motor fitness but not metabolic fitness was associated with hippocampal volume. After the 12-month intervention period, both, cardiovascular and coordination training led to increases in hippocampal volume. Our findings suggest that a high motor fitness level as well as different types of physical activity were beneficial to diminish age-related hippocampal volume shrinkage or even increase hippocampal volume.

Steroid hormones in the saliva of adolescents after different exercise intensities and their influence on working memory in a school setting

Little is known, about the influence of different exercise intensities on cognition, the concentration of steroid hormones (SHs), and their interaction in adolescents. Sixty high school students from the 9th grade were randomly assigned to two experimental (EG 1, EG 2) and a control group (CG). Saliva collection took place after a normal school lesson (t1) and after a 12-min resting control or exercise (t2) in a defined heart rate (HR) interval (EG 1: 50-65% HR max, n=18; EG 2: 70-85% HR max, n=20; CG: no intervention, n=21). Saliva was analyzed for T and C. Cognitive performance was assessed using a working memory task (Letter Digit Span; LDS), which took place after t1 and t2. Repeated measure ANOVAs revealed a significant group by test interaction, indicating an increase of C and T level only for EG 2. Results for LDS showed a significant improvement due to exercise when groups were split into low and high performer at pre-test with a higher improvement of the low performers. In addition, post-test T levels negatively correlated with changes in LDS performance in EG 2. The results indicate that the concentrations of C and T are intensity dependent, and that exercise improves working memory in low performing adolescents. Only increased T, however, seems to be related to pre-to-post-test changes in working memory by having a detrimental effect on performance.

Non-imprinted allele-specific DNA methylation on human autosomes

BackgroundDifferential DNA methylation between alleles is well established in imprinted genes and the X chromosomes in females but has rarely been reported at non-imprinted loci on autosomes.ResultsWe studied DNA methylation of cytosine-guanine dinucleotide (CpG) islands on chromosome 21 in leukocytes from several healthy individuals and observed novel cases of pronounced differential methylation of alleles. Allele-specific methylation affected complete CpG islands with methylation differences between alleles of up to 85%. The methylation differences between alleles were strongly correlated with the genotypes, excluding a connection to imprinting. We show that allele-specific methylation can lead to allelic repression of the methylated gene copy. Based on our results, allele-specific methylation is likely to affect about 10% of all human genes and to contribute to allele-specific expression and monoallelic gene silencing. Therefore, allele-specific methylation represents an epigenetic pathway of how genetic polymorphisms may lead to phenotypic variability. In most cases, we observed that some, but not all, heterozygous individuals showed allele-specific methylation, suggesting that allele-specific methylation is the outcome of an epigenetic drift, the direction of which is determined by the genetic differences between the alleles. We could show that the tendency to acquire hypermethylation in one allele was inherited.ConclusionsWe observed that larger differences in methylation levels between individuals were often coupled to allele-specific methylation and genetic polymorphisms, suggesting that the inter-individual variability of DNA methylation is strongly influenced by genetic differences. Therefore, genetic differences must be taken into account in future comparative DNA methylation studies.