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.

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.

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.

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.

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.

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.

Comparing manual and automatic segmentation of hippocampal volumes: reliability and validity issues in younger and older brains.

We compared hippocampal volume measures obtained by manual tracing to automatic segmentation with FreeSurfer in 44 younger (20-30 years) and 47 older (60-70 years) adults, each measured with magnetic resonance imaging (MRI) over three successive time points, separated by four months. Retest correlations over time were very high for both manual and FreeSurfer segmentations. With FreeSurfer, correlations over time were significantly lower in the older than in the younger age group, which was not the case with manual segmentation. Pearson correlations between manual and FreeSurfer estimates were sufficiently high, numerically even higher in the younger group, whereas intra-class correlation coefficient (ICC) estimates were lower in the younger than in the older group. FreeSurfer yielded higher volume estimates than manual segmentation, particularly in the younger age group. Importantly, FreeSurfer consistently overestimated hippocampal volumes independently of manually assessed volume in the younger age group, but overestimated larger volumes in the older age group to a less extent, introducing a systematic age bias in the data. Age differences in hippocampal volumes were significant with FreeSurfer, but not with manual tracing. Manual tracing resulted in a significant difference between left and right hippocampus (right > left), whereas this asymmetry effect was considerably smaller with FreeSurfer estimates. We conclude that FreeSurfer constitutes a feasible method to assess differences in hippocampal volume in young adults. FreeSurfer estimates in older age groups should, however, be interpreted with care until the automatic segmentation pipeline has been further optimized to increase validity and reliability in this age group.

How often do you cheat? Dispositional influences and intrapersonal stability of dishonest behavior.

Dishonesty, including lying, cheating, deception, and deviating from societal norms, has far-reaching implications across various aspects of modern society. From minor consequences like social discontent to severe outcomes such as economic damage through tax evasion, dishonest behavior affects us in multiple ways. This study investigates whether gender and psychological traits contribute to dishonest behavior, and whether unethical conduct is stable across diverse tasks. We examined 63 participants using a "Difference Spotting Task" (DST) and two motor tasks (1. coordinative throwing; 2. isometric strength). Dishonesty was measured by comparing self-reported performance with actual performance, allowing for a comprehensive analysis of both occurrence and extent of dishonesty. Our findings indicate that gender does not significantly influence the occurrence or extent of dishonest behavior. Moreover, we discovered that "Social Desirability" positively influences the extent of dishonesty, while "Task Orientation" increases the likelihood of engaging in dishonest acts. The study also reveals that the level of dishonesty remains relatively stable across all three tasks at an intrapersonal level.

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.

Cortical thickness changes following spatial navigation training in adulthood and aging.

A widespread network involving cortical and subcortical brain structures forms the neural substrate of human spatial navigation. Most studies investigating plasticity of this network have focused on the hippocampus. Here, we investigate age differences in cortical thickness changes evoked by four months of spatial navigation training in 91 men aged 20-30 or 60-70 years. Cortical thickness was automatically measured before, immediately after, and four months after termination of training. Younger as well as older navigators evidenced large improvements in navigation performance that were partly maintained after termination of training. Importantly, training-related cortical thickening in left precuneus and paracentral lobule were observed in young navigators only. Thus, spatial navigation training appears to affect cortical brain structure of young adults, but there is reduced potential for experience-dependent cortical alterations in old age.

Performance-related increases in hippocampal N-acetylaspartate (NAA) induced by spatial navigation training are restricted to BDNF Val homozygotes.

Recent evidence indicates experience-dependent brain volume changes in humans, but the functional and histological nature of such changes is unknown. Here, we report that adult men performing a cognitively demanding spatial navigation task every other day over 4 months display increases in hippocampal N-acetylaspartate (NAA) as measured with magnetic resonance spectroscopy. Unlike measures of brain volume, changes in NAA are sensitive to metabolic and functional aspects of neural and glia tissue and unlikely to reflect changes in microvasculature. Training-induced changes in NAA were, however, absent in carriers of the Met substitution in the brain-derived neurotrophic factor (BDNF) gene, which is known to reduce activity-dependent secretion of BDNF. Among BDNF Val homozygotes, increases in NAA were strongly related to the degree of practice-related improvement in navigation performance and normalized to pretraining levels 4 months after the last training session. We conclude that changes in demands on spatial navigation can alter hippocampal NAA concentrations, confirming epidemiological studies suggesting that mental experience may have direct effects on neural integrity and cognitive performance. BDNF genotype moderates these plastic changes, in line with the contention that gene-context interactions shape the ontogeny of complex phenotypes.

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.

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.

The interplay between cognitive and motor functioning in healthy older adults: findings from dual-task studies and suggestions for intervention.

Reaching late adulthood is accompanied by losses in physical and mental resources, but lifestyle choices seem to have a considerable influence on the aging trajectory. This review deals with the interplay between cognitive and motor functioning in old age, focusing on two different lines of research, namely (a) dual-task studies requiring participants to perform a cognitive and a motor task simultaneously, and (b) intervention studies investigating whether increases in physical fitness also lead to improvements in cognitive performance. Dual-task studies indicate that healthy older adults show greater performance reductions in both domains than young adults when performing a cognitive and a motor task simultaneously. In addition, older adults often tend to protect their motor functioning at the expense of the cognitive task when the situation involves a threat to balance. This can be considered an adaptive behavior since fall-related injuries can have severe consequences. Fitness intervention studies which increased the aerobic fitness of previously sedentary older adults have demonstrated impressive performance improvements in the cognitive domain, especially for tasks involving executive control processes. These findings are interesting in light of cognitive intervention studies, which often fail to find significant transfer effects to tasks that have not been trained directly. The authors argue that future research should compare the effects of cognitive and aerobic fitness interventions in older adults, and they present a study design in which cognition and fitness are trained sequentially as well as simultaneously. Finally, methodological issues involved in this type of research and potential applications to applied settings are discussed.

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.

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.

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.

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).