Different post-training processes in children's and adults' motor skill learning

Distinct mechanisms for online and offline motor skill learning across human development

The human central nervous system (CNS) undergoes tremendous changes from childhood to adulthood and this may affect how individuals at different stages of development learn new skills. Here, we studied motor skill learning in children, adolescents, and young adults to test the prediction that differences in the maturation of different learning mechanisms lead to distinct temporal patterns of motor learning during practice and overnight. We found that overall learning did not differ between children, adolescents, and young adults. However, we demonstrate that adult-like skill learning is characterized by rapid and large improvements in motor performance during practice (i.e., online) that are susceptible to forgetting and decay over time (i.e., offline). On the other hand, child-like learning exhibits slower and less pronounced improvements in performance during practice, but these improvements are robust against forgetting and lead to gains in performance overnight without further practice. The different temporal dynamics of motor skill learning suggest an engagement of distinct learning mechanisms in the human CNS during development. In conclusion, adult-like skill learning mechanisms favor online improvements in motor performance whereas child-like learning mechanisms favors offline behavioral gains. RESEARCH HIGHLIGHTS: Many essential motor skills, like walking, talking, and writing, are acquired during childhood, and it is colloquially thought that children learn better than adults. We investigated dynamics of motor skill learning in children, adolescents, and young adults. Adults displayed substantial improvements during practice that was susceptible to forgetting over time. Children displayed smaller improvements during practice that were resilient against forgetting. The distinct age-related characteristics of these processes of acquisition and consolidation suggest that skill learning relies on different mechanisms in the immature and mature central nervous system.

Active and Passive Offline Breaks Differentially Impact the Consolidation of Procedural Motor Memories in Children and Adults

INTRODUCTION

Short post-learning breaks, lasting from 5 to 30 min, transiently enhance procedural motor memory performance in adults. However, the impact of activity type (active vs. passive) during the offline break on sequential motor performance remains poorly investigated in children.

METHOD

This study examined the impact of active versus passive post-learning breaks on procedural motor memory in 116 healthy participants (58 children, aged 9.03 ± 1.19; 58 adults, aged 22.89 ± 1.77 years). Participants practiced a Finger Tapping Task, reproducing a five-element keypress sequence as fast and accurately as possible. The task included two sessions (S1 and S2) separated by either a short (30 min) or long (4 h) break. The first 30-min of the post-learning break included either a passive (remaining still) or an active (engaging in daily activities) condition.

RESULTS

Repeated-measures ANOVA revealed significant Session × Age group × Break duration and Session × Break type interaction effects (ps < 0.05). Post hoc analyses indicated Session effects in adults after both Break types, but only after short Break duration (S1 < S2, p < 0.001; long delay p = 0.1). In children, Session effects were observed after both short and long breaks, but only in the active Break type (S1 < S2, ps < 0.001; passive condition p = 0.1).

CONCLUSION

These results revealed spontaneous post-learning motor performance improvements at both short and long delays in children, but only in the active post-training condition, unlike adults who showed improvements only at short delays, regardless of activity type. This suggests developmental differences in offline conditions (duration and activity) linked to plasticity mechanisms underlying procedural motor memory consolidation.

Different time courses of maturation for learning and generalization following auditory training in children

OBJECTIVE

We recently demonstrated that learning abilities among school-age children vary following frequency discrimination (FD) training, with some exhibiting mature adult-like learning while others performing poorly (non-adult-like learners). This study tested the hypothesis that children's post-training generalisation is related to their learning maturity. Additionally, it investigated how training duration influences children's generalisation, considering the observed decrease with increased training in adults.

DESIGN

Generalisation to the untrained ear and untrained 2000 Hz frequency was assessed following single-session or nine-session 1000 Hz FD training, using an adaptive forced-choice procedure. Two additional groups served as controls for the untrained frequency.

STUDY SAMPLE

Fifty-four children aged 7-9 years and 59 adults aged 18-30 years.

RESULTS

(1) Only adult-like learners generalised their learning gains across frequency or ear, albeit less efficiently than adults; (2) As training duration increased children experienced reduced generalisation, similar to adults; (3) Children's performance in the untrained tasks correlated strongly with their trained task performance after the first training session.

CONCLUSIONS

Auditory skill learning and its generalisation do not necessarily mature contemporaneously, although mature learning is a prerequisite for mature generalisation. Furthermore, in children, as in adults, more practice makes rather specific experts. These findings should be considered when designing training programs.

Manual dexterity in school-age children measured by the Grooved Pegboard test: Evaluation of training effect and performance in dual-task

Background

Manual dexterity is the ability to manipulate objects using the hands and fingers for a specific task. Although manual dexterity is widely investigated in the general and special population at all ages, numerous aspects still remain to be explored in children. The aim of this study was to assess the presence of the training effect of the execution of the Grooved Pegboard test (GPT) and to measure the performance of the GPT in dual-task (DT), i.e., during a motor task and a cognitive task.

Methods

In this observational, cross-sectional study manual dexterity was assessed in children aged between 6 and 8. The procedure consisted of two phases: (1) the execution of five consecutive trials of the GPT to evaluate the training effect; (2) the execution of one trial of the GPT associated with a motor task (finger tapping test, GPT-FTT), and one trial of the GPT associated with a cognitive task (counting test, GPT-CT) to evaluate the performance in DT.

Results

As for the training effect, a significant difference (p < 0.001) between the five trials of the GPT (i.e., GPT1, GPT2, GPT3, GPT4, GPT5) was detected. In particular, we found a significant difference between GPT1 and GPT3 (p < 0.05), GPT1 and GPT4 (p < 0.001), and GPT1 and GPT5 (p < 0.001), as well as between GPT2 and GPT4 (p < 0.001), and GPT2 and GPT5 (p < 0.001).As for the performance in DT, no differences between the best trial of the GPT (i.e., GPT5) and both the GPT-FTT and GPT-CT was found.

Conclusion

Our findings suggest that the execution of the GPT in children has a training effect up to the third consecutive trial. Furthermore, the administration of the GPT in DT does not affect GPT performance.

Practice schedule and testing per se affect children's transfer abilities in a grapho-motor task

Children's ability to transfer the gains of a motor experience, such as learning to write a letter, to novel conditions, such as cursive writing of the same letter, are affected by the way in which the learning experience is parsed. Parsing may have limitations because a short session may hamper the engagement of procedural memory consolidation processes. Here, we compared the effects of two practice schedules with the total amount of practice identical training provided in a single-session practice versus multi-session practice, wherein each session on its own was insufficient for generating long-term gains. A total of 40 7- and 8-year-old children practiced the production of a novel letter form by connecting dots, namely, the Invented Letter Task (ILT). Multiple ILT-related transfer tasks were assessed at 24 h post-training and again at 4-5 weeks post-training. Although by the end of training the single-session practice group outperformed the multi-session practice group in speed and accuracy, at 24 h post-training both groups showed comparable gains. However, after multi-session practice, children were as fast or faster and more accurate in the transfer tasks. By 4-5 weeks post-training, the multi-session practice group showed larger gains in the trained condition, a speed advantage in the transfer tasks, and a significant improvement on the transfer tasks. The results suggest that parsing training over several brief sessions may lead to long-term gains in children's grapho-motor skills. Moreover, multi-session practice protocols may contribute to the potential for transfer and to more effective learning from experiences such as transfer tasks.

Second Graders' Grapho-Motor Skill Learning and Verbal Learning: The Effects of Socio-Educational Factors

Introduction: Children from low socioeconomic status (SES) families, and in particular, those with a lower level of maternal education, show lower fine-motor skills and lower vocabulary scores than their SES peers whose mothers have a higher level of education. Furthermore, low SES children frequently have difficulties in reading and spelling. These difficulties are attributed to deficits in the acquisition of skills through practice, such as those required for developing visual-motor routines, alongside deficits in the intentional acquisition of knowledge, such as those required in verbal learning. The aim of the current study was to test the effect of two background factors: low maternal education (ME) and risk of reading and spelling difficulties on practice-dependent learning of a motor task and intentional learning of a verbal task in second graders from low SES families. Methods: In 2016/17, 134 low-SES second graders with higher and lower ME (95 typical learners and 39 with reading and spelling difficulties) were assessed with (a) the Invented Letter Task (ILT; a grapho-motor skill learning task) across five time-points (initial- and end-training Day 1; initial- and end-training Day 2; and 2-weeks post-training), as well as an ILT transfer task; and (b) The Rey Auditory Verbal Learning Test (RAVLT; an intentional word-learning task in which a word list is read to children for five learning trials and is recalled 20 min later). Findings: Lower ME was associated with surplus segments in the performance of the motor task and its transfer to a novel condition as well as with lower recall on the verbal task, but not with the learning of both the motor and the verbal task. Having reading and spelling difficulties affected motor-task accuracy and also the way children learned the task, as evidenced by surplus segments at the beginning of Day 2, which were reduced with further practice. Conclusion: Low ME affected overall performance level. Reading and spelling difficulties resulted in atypical learning of the motor task. Future research on practice-dependent learning in the context of children coming from low SES families should focus on subgroups within this heterogeneous population.

Cognitive flexibility in children with Developmental Language Disorder: Drawing of nonexistent objects

Cognitive flexibility is the ability to adapt thoughts and behaviors to new environments. Previous studies investigating cognitive flexibility in children with Developmental Language Disorder (DLD) present contradictory findings. In the current study, cognitive flexibility was assessed in 5- and 6-year-old preschoolers with DLD (n = 23) and peers with typical development (TD; n = 50) using a nonexistent object drawing (NEOD) task. The children were asked to draw a nonexistent man and a nonexistent house. The children with DLD did not differ from their peers with TD on simple category changes, which were comprised of changes in the size or shape of parts of the object, change of the whole shape of the object, and deletion of parts of the object. Nevertheless, children with DLD made fewer more complex, high-level category changes, which included same-category insertions, position exchange of object's parts, and cross-category insertions. The difference between DLD and TD on high-level category changes was related to differences between the two groups in verbal short-term memory and inhibition. Furthermore, children with DLD made no changes to their original drawings of an existing man and house more often than their peers with TD. It is concluded that children with DLD aged 5-6 years show less flexibility on the NEOD task than age-matched children with TD. This difference in cognitive flexibility may be related to lower levels of verbal short-term memory and inhibition ability of children with DLD, or to different use of these cognitive skills on the NEOD task.