Effects of age simulation and age on motor sequence learning: Interaction of age-related cognitive and motor decline.

Aging is known to lead to decrements in sensory and cognitive functioning and motor performance. The purpose of the present experiment was twofold: a) We assessed the influence of wearing an age simulation suit on motor sequence learning, cognitive speed tasks and far visual acuity in healthy, younger adults. b) We evaluated the interaction of cognitive aging and declining motor sequence learning in older adults. In a between-subjects design we tested 11 younger adults (Mage = 23.6 years) without the age suit, 12 younger adults wearing the age suit (Mage = 23.2 years), and 23 older adults (Mage = 72.6 years). All participants learned a simple, spatial-temporal movement sequence on two consecutive days, and we assessed perceptual processing speed (Digit Symbol Substitution test and Figural Speed test) and far visual acuity. Wearing an age simulation suit neither affected the learning of the simple motor sequence nor the performance at the cognitive speed tasks in younger adults. However, far visual acuity suffered from wearing the suit. Younger adults with and without the suit showed better motor sequence learning compared to older adults. The significant correlations between the cognitive speed tests and the motor learning performance in older adults indicated that cognitive aging partially explains some of the variance in age-related motor learning deficits.

The influence of age and age simulation on task-difficulty choices in motor tasks.

Having a realistic perception of one's motor abilities is important for successful aging. We used two different motor tasks, carrying a tray with cube-towers (study 1; n = 20 young adults; n = 20 older adults), and stepping over a crossbar (study 2; n = 23 young adults; n = 21 older adults), to investigate how physical risk influences task-difficulty choices. We also investigated the effect of wearing an age simulation suit on young adults. For the tray-carrying task, older adults were more risk-tolerant in their task-difficulty choices. When stepping over the crossbar, older adults left a larger "safety-buffer" than young adults. When wearing the age suit, young adults adopted a more careful strategy in the stepping task. We conclude that healthy older adults flexibly adjust their strategies to postural risks, and that young adults' strategy-choices can be influenced by experimentally inducing some of the sensory-motor constraints of old age.

Mutual interference between memory encoding and motor skills: the influence of motor expertise.

In cognitive-motor dual-task situations, the extent of performance decrements is influenced by the attentional requirements of each task. Well-learned motor skills should be automatized, leading to less interference. This study presents two studies combining an episodic memory encoding task with well-practiced motor tasks in athletes. Study 1 asked 40 rowers (early teenagers to middle adulthood) to row on ergometers at slow or fast speeds. In study 2, Taekwondo athletes (n = 37) of different skill levels performed a well-practiced sequence of martial arts movements. Performing the motor task during encoding led to pronounced performance reductions in memory in both studies, with costs of up to 80%. Cognitive costs were even larger when rowing with the fast compared to the slow speed in study 1. Both studies also revealed decrements in motor performances under dual-task conditions: Rowing became slower and more irregular (study 1), and the quality of the Taekwondo performance was reduced. Although higher-level athletes outperformed others in motor skills under single-task conditions, proportional dual-task costs were similar across skill levels for most domains. This indicates that even well-practiced motor tasks require cognitive resources.

The Influence of Social Contexts on Motor and Cognitive Performance: Performing Alone, in Front of Others, or Coacting With Others.

Group settings can help or hinder performances. We conducted two studies in a sporting context. Participants performed alone and in groups in which the other participants served as spectators or as coactors. In Study 1, 33 CrossFit athletes performed a timed fine motor task (stacking cups) and a gross motor task (planks). Plank performance increased in front of spectators and in the coacting condition as compared with the alone condition, whereas stacking performances were not affected by the social context. Study 2 assessed a working memory task (three-back) and a timed obstacle course requiring primarily motor speed. Subjects were 42 sports students. Spectators led to performance deteriorations in the complex cognitive task but to improved performances in the simple motor task, supporting the predictions formulated by Strauss. Future research should investigate whether the effects are mediated by the perception of one's own performance compared with the group or by personality traits.

Table tennis expertise influences dual-task costs in timed and self-initiated tasks.

Theories on resource sharing predict that performances will suffer under dual-task conditions. However, increases in skill level should decrease attentional resources needed to perform a task, resulting in a reduction of dual-task costs. The current study investigates whether table tennis experts are better able than novices to keep up their motor and cognitive performances in a dual-task situation. Two different cognitive tasks, 3-back and Counting Backwards in steps of 7, and two different table tennis tasks, returns and serves, were assessed in each possible cognitive-motor task combination in a within-subjects design. While 3-back and returns were timed, Counting Backwards and serves were self-initiated. We assumed that self-initiated tasks increase dual-task costs, since the scheduling of the responses requires attentional resources. As predicted, dual-task costs of novices were considerably higher (35%) than those of experts, who did not show costs (-1%). The predicted increase of costs for self-initiated tasks was only observed in the experts, while novices showed a tendency to reduce their dual-task costs for self-initiated tasks. It is argued that this is due to the psychometric properties of the underlying task, since timed tasks were specified by a fixed number of targets and responses. We conclude that cognitive-motor dual-task costs may be a valuable measure of sporting skill, over and above "pure" motor or cognitive performances.

Tennis expertise reduces costs in cognition but not in motor skills in a cognitive-motor dual-task condition.

Dual-process theories predict performance reductions under dual-task situations (= situations where two tasks have to be processed and executed simultaneously), because limited cognitive resources have to be shared between concurrent tasks. Increases in expertise should reduce the attentional resources needed to perform a motor task, leading to reduced dual-task costs. The current studies investigated whether expert tennis players (performance ratings of 1 to 14 in the German system) show smaller costs compared to intermediate players (performance ratings of 15 to 23). Two studies assessed single- and dual-task performance in a within-subject design in the same tennis task, returning balls into a target field. Two different cognitive tasks were used, a 3-back working memory task in study 1, and a vocabulary-learning task (episodic memory) in study 2. As predicted, performance in both cognitive tasks was reduced during dual-tasking, while the accuracy of tennis returns remained stable under cognitive challenge. These findings indicate that skilled tennis players show a task-prioritization strategy in favor of the tennis task in a dual-task situation. In study 1, intermediate players showed higher overall dual-task costs than experts, but the group differences in dual-task costs did not reach significance in study 2. This may have been due to less pronounced expertise-differences between the groups in study 2. The findings replicate and extend previous expertise studies in sports to the domain of tennis. We argue that an athlete's ability to keep up cognitive and motor performances in challenging dual-task situations may be a valid indicator of skill level.

Negative Effects of Embodiment in a Visuo-Spatial Working Memory Task in Children, Young Adults, and Older Adults.

Studies examining the effect of embodied cognition have shown that linking one's body movements to a cognitive task can enhance performance. The current study investigated whether concurrent walking while encoding or recalling spatial information improves working memory performance, and whether 10-year-old children, young adults, or older adults (M age = 72 years) are affected differently by embodiment. The goal of the Spatial Memory Task was to encode and recall sequences of increasing length by reproducing positions of target fields in the correct order. The nine targets were positioned in a random configuration on a large square carpet (2.5 m × 2.5 m). During encoding and recall, participants either did not move, or they walked into the target fields. In a within-subjects design, all possible combinations of encoding and recall conditions were tested in counterbalanced order. Contrary to our predictions, moving particularly impaired encoding, but also recall. These negative effects were present in all age groups, but older adults' memory was hampered even more strongly by walking during encoding and recall. Our results indicate that embodiment may not help people to memorize spatial information, but can create a dual-task situation instead.

Age-related changes in children's cognitive-motor dual tasking: Evidence from a large cross-sectional sample.

Children coordinate two tasks simultaneously at several occasions throughout the day; however, this dual-task ability and its development across childhood are poorly understood. Therefore, the current study investigated age-related changes in children's dual-task ability using a large cross-sectional sample of 8- to 13-year-old children (N = 135). In our dual-task methodology, children were asked to walk across an electronic pathway while performing three concurrent cognitive tasks. These tasks targeted at children's executive function components: inhibition, switching, and updating skills. Our findings indicate associations between age and children's stride time variability but not with normalized velocity. Younger children showed higher stride time variability in the dual-task situation as compared with older children after accounting for their single-task performance, intelligence, anthropometric variables, and sex, indicating a more regular gait pattern in older children. Furthermore, age was differently related to children's accuracy in solving the concurrent cognitive tasks. Whereas age was associated with children's performance in the updating and switching task, there was no relation between age and children's inhibitory skills. In addition, our data imply that children's dual-task ability was associated with a number of individual variables. In particular, children with higher intelligence scores showed fewer errors and girls showed lower stride time variability in the dual tasks. Our results suggest a considerable developmental progression in children's ability to coordinate two simultaneous tasks across middle childhood. Furthermore, our study qualifies previous dual-task research and implies that heterogeneous findings may be related to a differential involvement of executive function components in the dual task.

Running During Encoding Improves Word Learning for Children.

The learning of new information is an important task in everyday life, especially at a young age. Acute physical exercise can facilitate cognitive processes in multiple ways, and previous studies have shown that memory can profit from physical exercise before and during the encoding of vocabulary. The current study investigates the interplay of movement and vocabulary learning and also addresses lifespan differences in these effects. Participants were recruited in a recreational basketball club. Children (n = 24, M age = 12.3 years; 13 girls), young adults (n = 30, M age = 21.5 years; 17 women), and older adults (n = 24, M age = 59.3 years; 9 women) learned 20 new pseudo-words, which corresponded to a German word. In a between-subjects design, encoding took place either while standing, while running, or while running and dribbling a basketball. Recall was assessed three times throughout the learning session and on the following day. In children, more words could be remembered in the running condition compared to the standing condition. There were no differences between conditions for the young and older adults. Age-dependent reasons for this pattern of results are discussed and embedded into the literature of physical exercise. Our result suggests that implementing learning activities into children's physical education or exercise activities could be beneficial.

How an Age Simulation Suit affects Motor and Cognitive Performance and Self-perception in Younger Adults.

BACKGROUND/STUDY CONTEXT: We assessed the influence of wearing an Age Simulation Suit (GERT) on gross motor, fine motor and cognitive performance in healthy young adults. METHODS: In a within-subjects design, we tested 20 young adults (M age = 22.3 years) with and without the Age Simulation Suit. We assessed gross motor (Functional Fitness test) and fine motor (Purdue Pegboard test) functioning, cognitive performance (Digit Symbol Substitution test), and questionnaires on perceived physical state and mood. Gross and fine motor tests provided norms for large samples of older adults. RESULTS: Wearing the Age Simulation Suit leads to significant performance reductions in all task dimensions, with large effect sizes. Depending on the subtest, participants' performances were reduced to the level of mid-50- to 85-years-olds for almost all tests of gross and fine motor performance. Mood and perceived physical state also declined while wearing the suit. CONCLUSION: We argue that the GERT suit offers an attractive possibility to experimentally simulate the effects of aging-related sensory and motor losses and propose future studies with this paradigm, in the context of cognitive-motor dual-tasking or motor learning.

Effects of various executive functions on adults' and children's walking.

Walking is human's most important locomotion. Until recently, walking was seen as an automated motor task that requires only minimal cognitive resources. However, recent studies indicate that walking requires higher-level cognitive processes such as executive functions. A different line of research suggests that executive functions consist of 3 core components: inhibition, switching, and updating. Combining these findings, the present study clarified which executive-function component is most essential for human walking. Applying a dual-task methodology, adults (n = 37) and 8- to 13-year-old children (n = 134) walked repeatedly across an electronic pathway while solving an inhibition, switching, and updating task. Both adults and children showed the largest gait alterations in the updating and switching task as opposed to inhibition. Likewise, their cognitive performance revealed the largest performance reductions from single- to dual-task situations in the updating task. Overall, our results highlight remarkable similarities in children's and adults' performance with updating working memory representations and switching between rule sets being the most essential cognitive processes for walking. These findings point to a general gait-cognition process. Results have important theoretical value and hold practical implications for creating effective intervention programs. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Table Tennis Experts Outperform Novices in a Demanding Cognitive-Motor Dual-Task Situation.

Theories on motor skill acquisition predict that earlier learning stages require more attention, which should lead to higher cognitive-motor dual-task interference in novices as compared to experts. Expert and novice table tennis players returned balls from a ball machine while concurrently performing an auditory 3-back task (working memory). The groups did not differ in 3-back performance in the single task. Cognitive dual-task performance reductions were more pronounced in novices. A similar pattern emerged for the number of missed balls in table tennis, except that experts outperformed novices already in the single task. Experts consistently showed costs of about 10%, while novices showed costs between 30% and 50%. The findings indicate that performances of novices suffer considerably in motor-cognitive dual-task situations.

Gene modification by fast-track recombineering for cellular localization and isolation of components of plant protein complexes.

To accelerate the isolation of plant protein complexes and study cellular localization and interaction of their components, an improved recombineering protocol is described for simple and fast site-directed modification of plant genes in bacterial artificial chromosomes (BACs). Coding sequences of fluorescent and affinity tags were inserted into genes and transferred together with flanking genomic sequences of desired size by recombination into Agrobacterium plant transformation vectors using three steps of E. coli transformation with PCR-amplified DNA fragments. Application of fast-track recombineering is illustrated by the simultaneous labelling of CYCLIN-DEPENDENT KINASE D (CDKD) and CYCLIN H (CYCH) subunits of kinase module of TFIIH general transcription factor and the CDKD-activating CDKF;1 kinase with green fluorescent protein (GFP) and mCherry (green and red fluorescent protein) tags, and a PIPL (His18 -StrepII-HA) epitope. Functionality of modified CDKF;1 gene constructs is verified by complementation of corresponding T-DNA insertion mutation. Interaction of CYCH with all three known CDKD homologues is confirmed by their co-localization and co-immunoprecipitation. Affinity purification and mass spectrometry analyses of CDKD;2, CYCH, and DNA-replication-coupled HISTONE H3.1 validate their association with conserved TFIIH subunits and components of CHROMATIN ASSEMBLY FACTOR 1, respectively. The results document that simple modification of plant gene products with suitable tags by fast-track recombineering is well suited to promote a wide range of protein interaction and proteomics studies.

Health Behavior Change in Older Adults: Testing the Health Action Process Approach at the Inter- and Intraindividual Level.

BACKGROUND: Health behavior change theories usually claim to be universally and individually applicable. Most research has tested behavior change theories at the interindividual level and within young-to-middle-aged populations. However, associations at the interindividual level can differ substantially from associations at the intraindividual level. This study examines the applicability of the Health Action Process Approach (HAPA) at the inter- and the intraindividual level among older adults. METHODS: Two intensive longitudinal studies examined the HAPA model covering two different health behaviors and two different time spans: Study 1 (physical activity, N = 52 × 6 monthly observations) and Study 2 (medication adherence, N = 64 × 30 daily observations). The HAPA constructs (risk awareness, outcome expectancy, self-efficacy, intention, action planning, action control), and self-reported behaviors were assessed. RESULTS: Overall, at the interindividual level, results of both studies largely confirmed the associations specified by the HAPA. At the intraindividual level, results were less in line with the HAPA. Only action control emerged as consistent predictor of behavior. CONCLUSIONS: This study emphasises the importance of examining health behavior change theories at both, the inter- and the intraindividual level.

Exercise-Induced Fitness Changes Correlate with Changes in Neural Specificity in Older Adults.

Neural specificity refers to the degree to which neural representations of different stimuli can be distinguished. Evidence suggests that neural specificity, operationally defined as stimulus-related differences in functional magnetic resonance imaging (fMRI) activation patterns, declines with advancing adult age, and that individual differences in neural specificity are associated with individual differences in fluid intelligence. A growing body of literature also suggests that regular physical activity may help preserve cognitive abilities in old age. Based on this literature, we hypothesized that exercise-induced improvements in fitness would be associated with greater neural specificity among older adults. A total of 52 adults aged 59-74 years were randomly assigned to one of two aerobic-fitness training regimens, which differed in intensity. Participants in both groups trained three times a week on stationary bicycles. In the low-intensity (LI) group, the resistance was kept constant at a low level (10 Watts). In the high-intensity (HI) group, the resistance depended on participants' heart rate and therefore typically increased with increasing fitness. Before and after the 6-month training phase, participants took part in a functional MRI experiment in which they viewed pictures of faces and buildings. We used multivariate pattern analysis (MVPA) to estimate the distinctiveness of neural activation patterns in ventral visual cortex (VVC) evoked by face or building stimuli. Fitness was also assessed before and after training. In line with our hypothesis, training-induced changes in fitness were positively associated with changes in neural specificity. We conclude that physical activity may protect against age-related declines in neural specificity.

Changes in fitness are associated with changes in hippocampal microstructure and hippocampal volume among older adults.

This study investigates the effects of fitness changes on hippocampal microstructure and hippocampal volume. Fifty-two healthy participants aged 59-74years with a sedentary lifestyle were randomly assigned to either of two levels of exercise intensity. Training lasted for six months. Physical fitness, hippocampal volumes, and hippocampal microstructure were measured before and after training. Hippocampal microstructure was assessed by mean diffusivity, which inversely reflects tissue density; hence, mean diffusivity is lower for more densely packed tissue. Mean changes in fitness did not differ reliably across intensity levels of training, so data were collapsed across groups. Multivariate modeling of pretest-posttest differences using structural equation modeling (SEM) revealed that individual differences in latent change were reliable for all three constructs. More positive changes in fitness were associated with more positive changes in tissue density (i.e., more negative changes in mean diffusivity), and more positive changes in tissue density were associated with more positive changes in volume. We conclude that fitness-related changes in hippocampal volume may be brought about by changes in tissue density. The relative contributions of angiogenesis, gliogenesis, and/or neurogenesis to changes in tissue density remain to be identified.

THE GENETICS OF EPIGENETIC INHERITANCE: MODES, MOLECULES, AND MECHANISMS.

Organisms adapt developmental and physiological features to local and transient conditions in part by modulating transcription, translation, and protein functions, usually without changing DNA sequences. Remarkably, these epigenetic changes sometimes endure through meiosis and gametogenesis, thereby affecting phenotypic variation across generations, long after epigenetic changes were triggered. Transgenerational effects challenge our traditional understanding of inheritance. In this review, we focus on patterns of inheritance, molecular features, mechanisms that lead from environmental and genetic perturbations to phenotypic variation in later generations, and issues about study design and replication.

Walking in high-risk settings: do older adults still prioritize gait when distracted by a cognitive task?

When a cognitive and a motor task like walking or keeping one's balance are performed concurrently, performance usually deteriorates. Older adults have often been shown to prioritize their motor performance in such dual-task situations, possibly to protect themselves from falls. The current study investigates whether these prioritization behaviors can still be observed when several challenges are combined. Younger (20-30 years old) and older adults (60-70 years old; n = 24 in each group) were asked to walk through virtual environments with and without a cognitive load (3-back task). Walking difficulty was increased by walking on an elevated surface or on a narrow as opposed to a broad track, or both. Walking instructions emphasized speed and accuracy (avoiding missteps). No instruction was given concerning which performance dimension should be prioritized during dual-task trials. Participants decreased their 3-back performance while walking. Younger adults maintained their walking speed on elevated surfaces and were able to keep the number of missteps low, even when walking on a narrow track while performing the cognitive task. Older adults increased their walking speed on elevated relative to even surfaces and committed more missteps under cognitive load. Results suggest that task prioritization might fail in healthy older adults if several challenges are combined in high-risk settings.

The influence of cognitive load and walking speed on gait regularity in children and young adults.

The dual-process account of sensorimotor-cognitive interactions postulates that easy cognitive tasks can lead to performance improvements in the motor domain (e.g., an increased stability while walking or balancing) across the lifespan. However, cross-domain resource competition can lead to performance decrements in motor tasks when the concurrent cognitive task is very difficult, and older adults have shown performance decrements in their motor functioning under such circumstances. Resource limitations are particularly pronounced not only in old adulthood, but also in childhood. The current study investigates the relationship of walking speed and cognitive load on walking regularity in 7- and 9-year olds and young adults, with 18 participants in each group. Participants were walking on a treadmill at their preferred speed, and with speeds that were 30% faster and 30% slower than preferred. Regularity of lower-body coordination was operationalized as the residual variance of principal component analyses performed on the data of a motion analysis system. All age groups showed a more regular gait with increasing walking speed. Young adults' gait regularity was not influenced by cognitive load, whereas children showed a U-shaped relationship of cognitive load and walking regularity, with the highest regularity when performing an easy cognitive task. It can be concluded that children are also influenced by cross-domain resources competition in challenging cognitive-motor dual-task situations.