The implicit benefit of learning without errors

A pilot cluster randomised controlled trial, of an IMPlicit learning approach versus standard care, on recovery of mobility following stroke (IMPS)

OBJECTIVES

To evaluate the delivery of rehabilitation using implicit motor learning principles in an acute stroke setting.

DESIGN

Pilot, assessor-blind, cluster randomised controlled trial with nested qualitative evaluation.

SETTING

Eight inpatient stroke units, UK.

PARTICIPANTS

People within 14 days of stroke onset, presenting with lower limb hemiplegia.

INTERVENTIONS

Participants at control clusters received usual care. Participants at intervention clusters received rehabilitation using an Implicit Learning Approach (ILA); primarily consisting of reduced frequency instructions/feedback, and promotion of an external focus of attention. Video recording was used to understand the ability of intervention site therapists to adhere to the implicit learning principles, and to compare differences between groups.

MEASURES

Ability to recruit and retain clusters/participants; suitability and acceptability of data collection processes; appropriateness of fidelity monitoring methods; and appropriateness of chosen outcome measures.

RESULTS

Eight stroke units participated, with four assigned to each group (intervention/control). Fifty-one participants were enrolled (intervention group 21; control group 30). Mean time since stroke was 6 days (SD 3.42; 0-14); mean age was 73 years (SD 14, 25-94). Of those approached to take part, 72% agreed. We found clear differences between groups with respect to the frequency and type of instructional statement. The ILA was acceptable to both patients and therapists.

CONCLUSION

It is feasible to evaluate the application and effectiveness of motor learning principles within acute stroke rehabilitation, using a cluster randomised design. A larger study is required to evaluate the benefits of each approach; we provide a range of sample size estimates required for this.

Enhancing task performance in adults with intellectual disability through modified goal management training and assistive technology with errorless learning: A randomized controlled trial

Individuals with intellectual disabilities often fail to learn complex tasks. Modified Goal Management Training (mGMT) or Errorless Learning combined with assistive technology (App + EL) can help. The goal is to demonstrate the effectiveness of mGMT and/or App + EL in learning complex tasks. We employed a randomized controlled crossover design. One group started with mGMT (N = 16), and the other with App + EL (N = 15). We compared their performance with that of a passive control group (N = 15). The training consisted of six sessions of 30 minutes each. Success was analyzed using the Goal Attainment Scale (GAS). Three different tasks were assessed before and after each intervention period: "Practiced", "Non-Practiced", or "Previously Practiced". Generalization was evaluated through neuropsychological tests. Results indicated that both interventions significantly improved "Practiced" tasks compared with "Non-Practiced" tasks and the control group. Crossing the intervention did not interfere with the stable performance on the "Previously Practiced" task. However, starting with mGMT reduced, but did not eliminate, the efficacy of App + EL after crossing, but this pattern was not observed for the reverse sequence. Only the Tower of London task documented improvements related to interventions. In conclusion, the mGMT and App + EL were effective in learning complex tasks and retaining performance after learning a second task.Trial registration: German Clinical Trials Register identifier: DRKS00021674.

The effect of adding real-time postural feedback in balance and mobility training in older adults: A systematic review and meta-analysis

OBJECTIVES

This study aimed to systematically review the additional value of providing real-time postural feedback during balance and mobility training in older people.

METHODS

PubMed, Embase, CINAHL, and Web-of-Science were searched from inception to August 2023. Studies comparing the effectiveness of feedback-based versus non-feedback-based postural balance or mobility training on balance or mobility outcomes were selected. Similar outcomes were pooled in meta-analyses using a random-effect model. The quality of evidence for available outcomes was rated by Grading of Recommendations Assessment, Development and Evaluation (GRADE).

RESULTS

Eight studies were identified with 203 subjects. Two studies showed that providing postural feedback immediately improved stability in static balance and gait. For the post-training effect, however, no significant change was found in trunk movement during single-leg standing (i.e., pitch angle, MD=0.65, 95 %CI=-0.77 to 2.07, low-quality; roll angle, MD=0.96, 95 %CI=-0.87 to 2.80, moderate-quality), in the Mini-BESTest (MD=1.88, 95 %CI=-0.05 to 3.80, moderate-quality), and in balance confidence (MD=0.29, 95 %CI=-3.43 to 4.2, moderate-quality). A worsened functional reach distance was associated with providing feedback during balance training (MD=-3.26, 95 %CI=-6.31 to -0.21, high-quality). Meta-analyses on mobility outcomes were mostly insignificant, except for the trunk-roll angle of walking (MD=0.87, 95 %CI=0.05 to 1.70, low-quality) and trunk-pitch angle of walking with head-turning (MD=1.87, 95 %CI=0.95 to 2.79, moderate-quality).

CONCLUSION

Adding real-time postural feedback to balance and mobility training might immediately improve stability in balance and mobility in older people. However, mixed results were reported for its post-training effect.

Does Dyadic Practice Interfere with the Type of Motor Learning Promoted by Analogy Instructions?

We investigated whether allowing individuals to exchange verbal information during dyadic practice changed the effect of analogy instructions intended to strengthen explicit motor learning by an implicit means. Forty-three right-handed college students performed golf putting, aiming at a target three meters away. Participants were assigned to one of two groups: Dyadic Practice Analogy Instruction or Individual Practice Analogy Instruction. Participants in the Dyadic Practice group were allowed to communicate with one another about the task during their practice. Before practice, participants performed a working memory capacity test. Both groups performed 180 trials of golf distributed across three days. On each day, there were four blocks of 15 trials. On the third day, participants reported the explicit rules they used to learn the task and they completed the Intrinsic Motivation Inventory. On the fourth day, they took three learning tests: retention, dual-task transfer, and social pressure transfer tests. Results of the retention test indicated that both groups learned the task comparably. Similarly, there were no significant group differences between the participants' number of explicit rules learned and their motivation levels on either of the transfer tests. Finally, only the participants in the Dyadic Practice Analogy Group showed a significant correlation between their performance on the dual-task transfer test and their working memory capacity. Overall, we found that dyadic practice did not interfere with the implicit type of motor learning promoted by analogy instruction (i.e., implicit learning).

Errorless Training Benefits Motor Learning and Kinematic Outcomes in Children With Autism Spectrum Disorders

Most children with Autism Spectrum Disorder (ASD) have some form of motor deficits. Additionally, based on executive dysfunction, working memory is often atypical in these children. Errorless learning reduces demands on working memory. In this study, we investigated the effectiveness of errorless training on these children's ability to learn golf putting. Participants (N = 20), aged 9-13 years (M = 10.15, SD = 1.4), were randomly assigned to either: (a) an errorless (ER) training group (n = 10) or (b) an explicit instruction (EI) group (n = 10). The ER group practiced putting from different distances without any instruction, while the EI group practiced putting at a particular distance with instruction. We measured motor performance (e.g., putting accuracy) and kinematic variables (e.g., putter face angle). One-way analyses of variance showed that motor performance significantly improved in both groups, but that the ER group showed significantly better accuracy retention (p < .028) and transfer learning (p < .047) than the instructional group. Kinematic variables were also significantly different between the two groups on the transfer test. These findings supported the benefits of errorless training compared to explicit instruction to teach motor skills to children with ASD.

Implicit motor learning in children with autism spectrum disorder: current approaches and future directions

Motor dysfunction is increasingly being viewed as a core characteristic of autism spectrum disorder (ASD) in children. In particular, children with ASD have difficulty in learning new motor skills and there is a need to develop effective methods to improve this. Previous research has found that children with ASD may retain the ability to implicitly learn motor skills in comparison to their explicit learning of motor skills, which is typically impaired. This literature mini review focuses on summarizing the study of implicit learning in the acquisition of motor skills in children with ASD. First, we briefly introduce several common implicit learning methods in children's motor skill learning. Second, we focus on the role of two important implicit learning approaches in motor skill learning, namely, an external focus of attention and analogy learning. Finally, based on our review of the existing studies, we present an outlook for future research and the areas that need to be improved in the practical teaching of implicit learning in the acquisition of motor skills in children with ASD.

Motor learning in golf-a systematic review

Golf is a sport that consists of complex movement skills that need to be executed with utmost precision. Consequently, motor skill learning plays a crucial role in golf, and large numbers of studies address various methods of motor learning. In the present review, we give a systematic overview of randomized controlled trials (RCTs) on motor learning of golf-specific motor skills. Three electronic databases were searched for RCTs looking at the effect of at least one learning method on performance in a golf-specific motor task. We grouped the studies depending on the learning strategies "cognitive training", "practice scheduling", "augmented feedback", "implicit and explicit learning" and "focus of attention". Fifty-two RCTs met the eligibility criteria and were included in the systematic review. Superior methods within their respective strategies were an external focus of attention and increasing contextual interference, as well as errorless learning. For "cognitive training" and "augmented feedback", no single method can be considered the most favorable. The overall biggest limitations were the lack of statistical power for more than half of the RCTs, and the fact that most studies of the present review investigated simple putting tasks in novices only. Although we have shown superiority of specific learning methods, transferability of the recommendations that can be derived from simple golf tasks in novices to sport-specific tasks in advanced players still has to be demonstrated and require study designs with the intention to provide practical recommendations for coaches and athletes in the sport of golf.

Experts' perspectives on how to promote implicit and explicit motor learning in children: A mixed-methods study

BACKGROUND

Little is known about how motor learning strategies (MLSs) can promote implicit and explicit motor learning processes. This study aimed to explore experts' perspectives on therapists' use of MLSs to promote specific learning processes in children with and without developmental coordination disorder (DCD).

METHODS

In this mixed-methods study, two consecutive digital questionnaires were used to ascertain the opinions of international experts. Questionnaire 2 explored the findings of Questionnaire 1 in greater depth. In order to reach a certain level of agreement about the classification of MLSs as promoting either (more) implicit or (more) explicit motor learning, 5-point Likert scales were used in addition to open-ended questions. The open-ended questions were analysed with a conventional analysis approach. Open coding was performed by two reviewers independently. Categories and themes were discussed within the research team, taking both questionnaires as one dataset.

RESULTS

Twenty-nine experts from nine different countries with different backgrounds in research, education and/or clinical care completed the questionnaires. The results of the Likert scales showed large variation. Two themes emerged from the qualitative analyses: (1) Experts found it difficult to classify MLSs as promoting either implicit or explicit motor learning, and (2) experts stressed the need for clinical decisionmaking when choosing MLSs.

CONCLUSIONS

Insufficient insight was gained into how MLSs could promote (more) implicit or (more) explicit motor learning in children in general and in children with DCD specifically. But this study demonstrated the importance of clinical decisionmaking to model and adapt MLSs to child, task and environment, with therapists' knowledge of MLSs being an important prerequisite. Research is needed to better understand the various learning mechanisms of children and how MLSs can be used to manipulate these mechanisms.

Short-term evidence of partner-induced performance biases in simultaneous and alternating dyad practice in golf

Actions in social settings are often adapted based on co-actors. This adaptation can occur because one actor "co-represents" the actions and plans of another. Co-representation can result in motor contagion errors, whereby another's actions unintentionally interfere with (negatively impact) the actor. In sports, practice often takes place simultaneously or alternating with a partner. Co-representation of another's task could either harm or benefit skill retention and transfer, with benefits due to variable experiences and effortful processes in practice. Here, dyad groups that either alternated or simultaneously practiced golf putting to different (near vs. far) targets were compared to alone groups (n = 30/group). We focused on errors in distance from the target and expected overshooting for near-target partners paired with far-target partners (and undershooting for far-target partners paired with near-target partners), when compared to alone groups. There was evidence of co-representation for near-target partners paired with far-target partners. We also saw trial-to-trial error-based adjustments based on a partner's outcome in alternating dyads. Despite differences in practice between dyad and alone groups, these did not lead to costs or benefits at retention or transfer. We conclude that the social-context of motor learning impacts behaviours of co-actors, but not to the detriment of overall learning.

Imagine to automatize: automatization of stimulus-response coupling after action imagery practice in implicit sequence learning

Action imagery practice (AIP) describes the repetitive imagination of an action to improve subsequent action execution. Because AIP and action execution practice (AEP) draw on partly similar motor mechanisms, it was assumed that AIP may lead to motor automatization, which is observable in a reduction of dual-task costs after AEP. To investigate automatization in AIP, we compared dual-task and single-task performance in practice and random sequences in pretests and posttests. All participants practiced serial reactions to visual stimuli in ten single-task practice sessions. An AIP group imagined the reactions. An AEP group and a control practice group executed the reactions. Practice followed a sequential sequence in AIP and AEP but was random in control practice. In dual-task test conditions, tones were counted that appeared in addition to the visual stimuli. RTs decreased from pretest to posttest in both practice and random sequences in all groups indicating general sequence-unspecific learning. Further, RTs decreased to a greater extent in the practice sequence than in the random sequence after AIP and AEP, indicating sequence-specific learning. Dual-task costs-the difference between RTs after tone and no tone events-were reduced independent from the performed sequence in all groups indicating sequence-unspecific automatization. It is concluded that the stimulus-response coupling can be automatized by both, AEP and AIP.

Implicit Motor Learning Strategies Benefit Dual-Task Performance in Patients with Stroke

Background and Objectives: In stroke rehabilitation, the use of either implicit or explicit learning as a motor learning approach during dual tasks is common, but it is unclear which strategy is more beneficial. This study aims to determine the benefits of implicit versus explicit motor learning approaches in patients with stroke. Materials and Methods: Seventeen patients with stroke and 21 control participants were included. Motor learning was evaluated using the Serial Reaction Time Task (SRTT) in the context of dual-task conditions. The SRTT was conducted on two separate days: one day for implicit learning conditions and the other day for explicit learning conditions. Under the explicit learning conditions, a task rule was given to the participants before they started the task, but not under the implicit learning conditions. Learning scores were calculated for both implicit and explicit learning, and these scores were then compared within groups for patients with stroke and controls. We calculated the difference in learning scores between implicit and explicit learning and conducted a correlation analysis with the Trail Making Test (TMT) Parts A and B. Results: Learning scores on the SRTT were not different between implicit and explicit learning in controls but were significantly greater in patients with stroke for implicit learning than for explicit learning. The difference in learning scores between implicit and explicit learning in patients with stroke was correlated with TMT-A and showed a correlation trend with TMT-B. Conclusions: Implicit learning approaches may be effective in the acquisition of motor skills with dual-task demands in post-stroke patients with deficits in attention and working memory.

That looks easy! Evidence against the benefits of an easier criterion of success for enhancing motor learning

OPTIMAL theory predicts providing learners with a relatively easier criterion of success during practice enhances motor learning through increased self-efficacy, perceptions of competence, and intrinsic motivation. However, mixed results in the literature suggest this enhancement effect may be moderated by the number of successes achieved by learners practicing with the difficult criterion. To investigate this possibility, we manipulated quantity of practice to affect the absolute number of successes achieved by learners practicing with different success criteria. Eighty participants were divided into four groups and performed 50 or 100 trials of a mini-shuffleboard task. Groups practiced with either a large or a small zone of success surrounding the target. Learning was assessed 24 h after acquisition with retention and transfer tests. In terms of endpoint accuracy and precision, there were no learning or practice performance benefits of practicing with an easier criterion of success, regardless of the number of trials. This absence of a criterion of success effect was despite the efficacy of our manipulation in increasing the number of trials stopping within the zone of success, self-efficacy, perceptions of competence, and, for participants with 100 trials, intrinsic motivation. An equivalence test indicated that the effect of criterion of success was small, if existent. Moreover, at the individual level, intrinsic motivation did not predict posttest or acquisition performance. There were no benefits of easing the criterion of success on pressure, effort, accrual of explicit knowledge, or conscious processing. These data challenge key tenets of OPTIMAL theory and question the efficacy of easing criterion of success for motor learning.

Does learning a skill with the expectation of teaching it impair the skill's execution under psychological pressure if the skill is learned with analogy instructions?

OBJECTIVE

Having learners practice a motor skill with the expectation of teaching it (versus an expectation of being tested on it) has been revealed to enhance skill learning. However, this improvement in skill performance is lost when the skill must be performed under psychological pressure due to 'choking under pressure.' The present study investigated whether this choking effect is caused by an accrual of declarative knowledge during skill practice and could be prevented if a technique (analogy instructions) to minimize the accrual of declarative knowledge during practice is employed.

DESIGN

We used a 2 (Expectation: teach/test) x 2 (Instructions: analogy/explicit) x 2 (Posttest: low-pressure/high-pressure) mixed-factor design, with repeated measures on the last factor.

METHODS

One-hundred fifty-six participants were quasi-randomly assigned (based on sex) to one of four groups. Participants in the teach/analogy and teach/explicit groups practiced golf putting with the expectation of teaching putting to another participant, and analogy instructions or explicit instructions, respectively. Participants in the test/analogy and test/explicit groups practiced golf putting with the expectation of being tested on their putting, and analogy instructions or explicit instructions, respectively. The next day all participants completed low- and high-pressure putting posttests, with their putting accuracy serving as the dependent variable.

RESULTS

We observed an Expectation x Instructions × Posttest interaction, such that a main effect of expectation was found in the low-pressure posttest, with the teach group exhibiting superior accuracy, and an Expectation × Instructions interaction was revealed for the high-pressure posttest. This interaction resulted from the teach group showing greater accuracy than the test group exclusively when receiving analogy instructions.

CONCLUSION

Results show that participants who practiced with the expectation of teaching exhibited superior learning and indicate that they choked under pressure likely due to their accrual of declarative knowledge during practice, since the choking effect was prevented by having them practice with analogy instructions. Accordingly, having learners practice with the expectation of teaching and techniques that minimize the accrual of declarative knowledge is recommended.

Comparing the Effects of Differential and Visuo-Motor Training on Functional Performance, Biomechanical, and Psychological Factors in Athletes after ACL Reconstruction: A Randomized Controlled Trial

Variation during practice is widely accepted to be advantageous for motor learning and is, therefore, a valuable strategy to effectively reduce high-risk landing mechanics and prevent primary anterior cruciate ligament (ACL) injury. Few attempts have examined the specific effects of variable training in athletes who have undergone ACL reconstruction. Thereby, it is still unclear to what extent the variations in different sensor areas lead to different effects. Accordingly, we compared the effects of versatile movement variations (DL) with variations of movements with emphasis on disrupting visual information (VMT) in athletes who had undergone ACL reconstruction. Forty-five interceptive sports athletes after ACL reconstruction were randomly allocated to a DL group (n = 15), VT group (n = 15), or control group (n = 15). The primary outcome was functional performance (Triple Hop Test). The secondary outcomes included dynamic balance (Star Excursion Balance Test (SEBT)), biomechanics during single-leg drop-landing task hip flexion (HF), knee flexion (KF), ankle dorsiflexion (AD), knee valgus (KV), and vertical ground reaction force (VGRF), and kinesiophobia (Tampa Scale of Kinesiophobia (TSK)) assessed before and after the 8 weeks of interventions. Data were analyzed by means of 3 × 2 repeated measures ANOVA followed by post hoc comparison (Bonferroni) at the significance level of p ≤ 0.05. Significant group × time interaction effects, main effect of time, and main effect of group were found for the triple hop test and all eight directions, SEBT, HF, KF, AD, KV, VGRF, and TSK. There was no significant main effect of group in the HF and triple hop test. Additionally, significant differences in the triple hop test and the seven directions of SEBT, HF, KF, KV, VGRF, and TSK were found between the control group and the DL and VMT groups. Between group differences in AD and the medial direction of SEBT were not significant. Additionally, there were no significant differences between VMT and the control group in the triple hop test and HF variables. Both motor learning (DL and VMT) programs improved outcomes in patients after ACL reconstruction. The findings suggest that DL and VMT training programs lead to comparable improvements in rehabilitation.

Visual illusions influence proceduralized sports performance

Does the Ebbinghaus visual illusion really influence sports performances? Does the influence depend on the type of knowledge (procedural vs. declarative) that guides movement? To address these questions, we evaluated the knowledge hypothesis, a novel hypothesis according to which the more sports performance relies on procedural knowledge, the more it will be influenced by visual illusions. In the context of golf putting, we first used the high-error/low-error motor-learning technique (Experiment 1) or varied the number of practice trials (Experiment 2) to induce novice participants to rely more on procedural knowledge than on declarative knowledge (or vice versa). We then manipulated the perceived size of two golf holes by projecting a ring of small or large circles around them, which caused the holes to appear larger or smaller, respectively. This Ebbinghaus visual illusion had an influence on putting in both experiments. We also observed a pattern of findings consistent with the knowledge hypothesis: the procedural groups were moderately influenced by the illusion when putting, but the declarative groups were influenced only weakly, at best. Among the participants most sensitive to the illusion, the analyses confirmed a significantly stronger influence for the procedural group. Overall, these findings demonstrate that the effect of visual illusions on sports performance is a reliable phenomenon for proceduralized actions. The knowledge hypothesis represents an attractive way of reconciling earlier divergent findings.

Improvement of the ability to recover balance through versatile kinesthetic learning experiences

The purpose of the present study was to compare learners' movement variability while maintaining balance and the ability to recover balance using the kinesthetic-experiential learning (KEL) method of implicit learning and the model-mastery learning (MML) method of explicit learning. The participants were 29 healthy university students. They were randomly divided into two groups (KEL and MML). They were required to balance both knees on an exercise ball. The balancing time and the ability to recover their balance were measured using motion capture. Results indicated that balancing time was significantly improved for both learning methods. Regarding the learners' movements while maintaining balance, they maintained balance while moving in the KEL method, whereas they maintained balance by keeping the entire body stationary in the MML method. Concerning the ability to recover, the KEL method improved the balance recovery ability more effectively than the MML method. Therefore, we concluded that using the KEL method at the initial stage of learning improves learners' balance recovery ability and increases movement variability.

Individual differences in working memory capacity and conscious processing do not explain explicit and implicit learning outcomes in physical education

This study examined the effects of explicit versus implicit learning methods on motor learning and self-efficacy of 11-to 14-year old students (n = 81) practicing the basketball layup during physical education. The main aim was to test the effects of students' verbal working memory capacity (WMC) and propensity for conscious motor processing (CMP) on explicit and implicit learning outcomes. The students practiced basketball layups for three weeks (one session/week) during regular PE classes under practice conditions that either promoted explicit or implicit learning. Verbal WMC and CMP propensity were measured separately. At the posttest, students had significantly improved their layup performance and technique, and self-efficacy, but no differences were noted between the intervention groups (explicit vs. implicit). Students' verbal WMC and CMP propensity did not differentially predict the learning outcomes for the explicit or implicit learning groups. Therefore, in this PE setting, both explicit and implicit learning methods seemed to similarly improve movement skill. Further study is needed to examine under which conditions individual constraints such as verbal WMC and propensity for conscious processing influence the effects of explicit and implicit learning.

Let the force guide you: a performance-based adaptive algorithm for postural training using haptic feedback

Motor learning is an essential component of human behavior. Many different factors can influence the process of motor learning, such as the amount of practice and type of feedback. Changes in task difficulty during training can also considerably impact motor learning. Typical motor learning studies include a sequential variation of task difficulty, i.e., easy to challenging, irrespective of user performance. However, many studies have reported the importance of performance-based task difficulty variation for effective motor learning and skill transfer. A performance-based adaptive algorithm for task difficulty variation based on the challenge-point framework is proposed in this study. The algorithm is described for postural adaptation during simultaneous upper-limb training. Ten healthy participants (28 ± 2.44 years) were recruited to validate the algorithm. Participants adapted to a postural target of 20° in the anterior direction from the initial upright posture while performing a unimanual reaching task using a robotic device. Results suggest a significant decrease in postural error after training. The algorithm successfully adapted the task difficulty based on the performance of the user. The proposed algorithm could be modified for different motor skills and can be further evaluated for different applications in order to maximize the potential benefits of rehabilitation sessions.

Investigating the Effects of Differential Learning on Golfers' Pitching Performance as a Function of Handicap

Traditionally, golf instruction has been oriented toward imitation of role models, guided by errors that surround a channel of supposedly correct repetition. Recent motor learning approaches relying on the dynamics of living systems suggest the inclusion of additional noise during practice for supporting players' movement exploration and improving adaptability that in consequence will lead to increased performance. While the effectiveness of this approach has now been demonstrated in many sports, research exploring the effects of differential learning (DL) in golf is scarce, especially when considering different shot distances and players with various handicap levels. Therefore, the purpose of this study was to compare the effects of an enriched learning and information intervention as opposed to a more constrained approach, on the pitching performance of golfers with different handicaps from different distances. A total of 29 adolescent golfers with an average experience of 7.8 years were divided into a DL (n = 15) and a repetitive-oriented (RB, n = 14) group. Both groups were further compared dependent on their handicap level (DL, low handicap n = 7, high handicap n = 8; RB, low handicap n = 5, high handicap n = 9). The TrackMan 4 was used to measure the shot performance for 20 m, 35 m, and 50 m distances (10 shots from each distance) based on a pre- and post-test design. Each group performed the same number of trials (n = 270, 9 executions per distance per session) across 10 sessions. Analysis of covariance (ANCOVA) was used for the statistical analysis, using the pre-test as covariate and the post-test as dependent variable. The DL group revealed advantageous adaptations in the attack and face angle (p ≤ 0.05), while also in the dynamic loft (p ≤ 0.05), mostly for the 35 m and 50 m. In addition, this intervention led to improvements in the score, club head speed, and carry distance for the 50 m when compared to the RB (p ≤ 0.05; small effects). The low handicap players from the DL group also revealed adaptation in the angles' variables (p ≤ 0.05) when compared with high handicap players, who improved the score (p ≤ 0.05) in all distances after intervention. The low handicap players from the RB group improved the score (p ≤ 0.05) and club speed (p ≤ 0.05) for the 20 and 35 m, while the high handicap golfers revealed higher improvements for these variables only in the 50 m distance condition. Overall, coaches may incorporate approaches into their skill training that increase the number of opportunities to improve the performance of both experienced and non-experienced players by promoting the adaptability of movement patterns.

Learning Multiple Movements in Parallel-Accurately and in Random Order, or Each with Added Noise?

Traditionally, studies on learning have mainly focused on the acquisition and stabilization of only single movement tasks. In everyday life and in sports, however, several new skills often must be learned in parallel. The extent to which the similarity of the movements or the order in which they are learned influences success has only recently begun to attract increased interest. This study aimed to compare the effects of CI in random practice order (high CI) with differential learning (DL) in learning three volleyball skills in parallel. Thirty-two advanced beginners in volleyball (mean age = 24, SD = 2.7) voluntarily participated in the study. Within a pre-, post-, retention test design, an intervention of six weeks and one week retention phase, the effects of three practice protocols of a CI, DL, and control (CO) group were compared. Three different volleyball skills (underhand pass, overhand pass, and overhand serve) were trained with emphasis on accuracy. Results showed statistically significant higher rates of improvement in the acquisition and learning phases for the DL group compared to the CI and CO groups. The differences were associated with moderate to high effect sizes in all individual skills and in the combined skills. The findings show more agreement with DL than with CI theory.

A scoping review of the application of motor learning principles to optimize myoelectric prosthetic hand control

Although prosthetic hand rejection rates remain high, evidence suggests that effective training plays a major role in device acceptance. Receiving training early in the rehabilitation process also enhances functional prosthetic use, decreases the likelihood of developing an overreliance on the intact limb, and reduces amputation-related pain. Despite these obvious benefits, there is a current lack of evidence regarding the most effective training techniques to facilitate myoelectric prosthetic hand control, and it remains unknown whether training is effective in facilitating the acquisition and transfer of prosthetic skill. In this scoping review, we introduced and summarized key motor learning principles related to attentional focus, implicit motor learning, training eye-hand coordination, practice variability, motor imagery, and action observation, and virtual training and biofeedback. We then reviewed the existing literature that has applied these principles for training prosthetic hand control before outlining future avenues for further research. The importance of optimizing early and appropriate training cannot be overlooked. While the intuition and experience of clinicians holds enormous value, evidence-based guidelines based on well-established motor learning principles will also be crucial for training effective prosthetic hand control. While it is clear that more research is needed to form the basis of such guidelines, it is hoped that this review highlights the potential avenues for this work.

An Examination of the Contextual Interference Effect and the Errorless Learning Model during Motor Learning

The purpose of this study was to investigate the combined effects of random and block practice, with errorless and errorful conditions, on motor learning. One hundred-twenty participants (all male, Mage = 21.19 ± 1.4 years) were randomly assigned to one of eight groups. Participants completed a dart throwing task across the experimental phases. In the retention test, evidence supporting the CI effect was found in the 'errorless' conditions, but not in the 'errorful' conditions. In the transfer tests, the findings indicated that the impact of errorless and errorful conditions on participants' automation levels depends on the structure of practice. Participants in the Random-Errorless group performed better in the transfer tests than those in the Random group and the Random-Errorful group, suggesting greater automation levels following errorless practice.

Clustering analysis of movement kinematics in reinforcement learning

Reinforcement learning has been used as an experimental model of motor skill acquisition, where at times movements are successful and thus reinforced. One fundamental problem is to understand how humans select exploration over exploitation during learning. The decision could be influenced by factors such as task demands and reward availability. In this study, we applied a clustering algorithm to examine how a change in the accuracy requirements of a task affected the choice of exploration over exploitation. Participants made reaching movements to an unseen target using a planar robot arm and received reward after each successful movement. For one group of participants, the width of the hidden target decreased after every other training block. For a second group, it remained constant. The clustering algorithm was applied to the kinematic data to characterize motor learning on a trial-to-trial basis as a sequence of movements, each belonging to one of the identified clusters. By the end of learning, movement trajectories across all participants converged primarily to a single cluster with the greatest number of successful trials. Within this analysis framework, we defined exploration and exploitation as types of behavior in which two successive trajectories belong to different or similar clusters, respectively. The frequency of each mode of behavior was evaluated over the course of learning. It was found that by reducing the target width, participants used a greater variety of different clusters and displayed more exploration than exploitation. Excessive exploration relative to exploitation was found to be detrimental to subsequent motor learning.

NEW & NOTEWORTHY The choice of exploration versus exploitation is a fundamental problem in learning new motor skills through reinforcement. In this study, we employed a data-driven approach to characterize movements on a trial-by-trial basis with an unsupervised clustering algorithm. Using this technique, we found that changes in task demands and, in particular, in the required accuracy of movements, influenced the ratio of exploration to exploitation. This analysis framework provides an attractive tool to investigate mechanisms of explorative and exploitative behavior while studying motor learning.

Interleaved practice benefits implicit sequence learning and transfer

Compared to blocked practice, interleaved practice of different tasks leads to superior long-term retention despite poorer initial acquisition performance. This phenomenon, the contextual interference effect, is well documented in various domains but it is not yet clear if it persists in the absence of explicit knowledge in terms of fine motor sequence learning. Additionally, while there is some evidence that interleaved practice leads to improved transfer of learning to similar actions, transfer of implicit motor sequence learning has not been explored. The present studies used a serial reaction time task where participants practiced three different eight-item sequences that were either interleaved or blocked on Day 1 (training) and Day 2 (testing). In Experiment 1, the retention of the three training sequences was tested on Day 2 and in Experiment 2, three novel sequences were performed on Day 2 to measure transfer. We assessed whether subjects were aware of the sequences to determine whether the benefit of interleaved practice extends to implicitly learned sequences. Even for participants who reported no awareness of the sequences, interleaving led to a benefit for both retention and transfer compared to participants who practiced blocked sequences. Those who trained with blocked sequences were left unprepared for interleaved sequences at test, while those who trained with interleaved sequences were unaffected by testing condition, revealing that learning resulting from blocked practice may be less flexible and more vulnerable to testing conditions. These results indicate that the benefit of interleaved practice extends to implicit motor sequence learning and transfer.

Preventing a loss of accuracy of the tennis serve under pressure

Dynamically squeezing the left hand (left hand dynamic handgrip) has been shown to be effective in preventing choking under pressure in right-handers in a variety of sports. The current study assessed the effectiveness of the left hand dynamic handgrip in preventing a loss of accuracy of tennis serves in competitive situations. Twenty right-handed highly skilled junior athletes performed eight tennis serves at a target without pressure (pre-test), followed by eight serves under pressure (post-test). Ten of the participants conducted the left hand dynamic handgrip prior to the post-test, while the other ten performed an equivalent handgrip with their right hand. The serving accuracy of the group performing the handgrip with their right hand decreased significantly from pre- to post-test, while the accuracy of the left hand dynamic handgrip group remained stable. The results indicate the left hand dynamic handgrip to be effective in preventing reduced accuracy of the tennis serve in competition situations as a form of choking under pressure. This technique could easily be integrated into tennis players' serving routines and promote stable match performance in competitions.

Examining the Antecedent Role of Movement Proficiency in Child Development: Study Protocol

Background: Decades of research, largely from associational studies, show that the relationships of movement proficiency with the cognitive and social aspects of development are particularly strong in early childhood. Children who move proficiently tend to have better cognitive skills and social behaviors. However, the mechanisms that underpin these relationships remain unclear and research that explores causation is necessary. This study will explore the antecedent role of movement proficiency in the cognitive and social domains of child development, by examining whether a targeted movement skills training program facilitates improvements in cognitive and social skills.

Methods: A group-randomized controlled trial will be conducted, implementing a fundamental movement skills training program in Hong Kong kindergartens. Participants will consist of children aged 3–5 years (N = 158) who will be randomly allocated by class to either a training or active control condition. The training program (10 weeks × 2 bouts) will be informed by an error-reduced approach to skills learning, which will involve careful design and manipulation of equipment and training environment to minimize practice errors. The active control condition will consist of typical movement activities implemented in the kindergartens in the context of the local curriculum guide. Outcomes will be measured using standardized tests of gross motor skills proficiency, executive functioning, and social skills. Measurements will occur at baseline, mid-training, post-training, and follow-up. Latent variable longitudinal modeling will be used to analyze changes in the outcomes, with covariates that include sex, body composition, fine motor skills, and physical activity.

Expected Results: The findings will subsequently be reported consistent with the Consolidated Standards of Reporting Trials (CONSORT) statement. Contributions to knowledge and understanding of child development are expected, through evidence of causal mechanisms surrounding the relationship of motor with cognitive and social development. The findings will also inform policy and practice related to early childhood development and education.

Implicit motor learning in primary school children: A systematic review

The aim of this study was to assess the current state of evidence and methodological quality of studies on implicit and explicit motor learning in both typically developing children and children with developmental disorders. A systematic literature review was conducted on the experimental literature published up to April 2020. A total of 25 studies were included. Studies were evaluated on methodological quality, paradigm used, and level of evidence. The results showed that implicit paradigms are as effective as explicit paradigms in both groups of children. Studies are predominantly experimental in nature involving mostly upper limb aiming tasks. The few studies that were performed outside the lab (n = 5) suggest superior efficacy of the implicit paradigm. Methodological quality varied between studies and was not always of sufficient standard to allow conclusions. In particular, manipulation checks were only performed in 13 studies (52% of all studies), limiting conclusions. Further progress can be made by focussing on improving methodological quality through retention testing by the inclusion of a control group, by the inclusion of a manipulation check, and via assessment of relevant co-variables, such as working memory, age, and motor competence.

Does a Cognitive Task Promote Implicit or Explicit Motor Learning?

This study examined whether use of an N-back task could promote implicit and explicit motor learning. In Experiment 1, 30 healthy adults were assigned to an N-back task group (NTG) or a control task group (CG). All participants performed the serial reaction time task (SRTT) and generation task after either the N-back or control tasks. The results did not reveal whether the N-back task promoted implicit or explicit motor learning because participants in the NTG noticed a hidden loop in the SRTT and this "awareness" made it difficult to interpret the results in Experiment 1. In Experiment 2, we examined whether the N-back task promoted explicit motor learning only using a modified SRTT. Thirty healthy adults were assigned to the NTG or the CG. On day 1, all participants performed the modified SRTT after either the N-back or control tasks. On day 7, all participants repeated the modified SRTT. As a result, the performance on the modified SRTT was faster in the NTG than in the CG on days 1 and 7. In summary, although the N-back task might promote explicit motor learning, the present study could not clearly conclude whether the N-back task promoted implicit and explicit motor learning.

Understanding Motor Skill Learning as Related to Dentistry

Learning dental procedures is a complex task involving the development of fine motor skills. The reported use of theories and/or evidence for designing learning activities to develop the fine motor skills needed for dental practice is limited. The aim of this review is to explore the available body of knowledge related to learning motor skills relevant to dentistry. Evidence from studies investigating motor skill learning highlights the negative impact of self-focus and self-regulation on learning outcomes, particularly during the early stages of learning. The development of activities and schedules that enable novices to demonstrate characteristics similar to experts, without the reported long period of 'deliberate practice', is clearly of value. Outcomes of learning implicitly are important in dentistry because working under stressful conditions is common, either during undergraduate study or in practice. It is suggested that learning implicitly in the simulation stage can reduce disrupted performance when transitioning to clinical settings. Therefore, further investigation of effective methods for learning dental fine motor skills is indicated, using approaches that result in robust performance, even under stressful conditions.

Evaluation of Conscious Monitoring and Movement Control Efforts Among Dental Students

Prior research has demonstrated that motor skill learning is often disrupted by self-focus and attempts to control movement. The propensity for reinvestment (i.e., self-focus and movement control) has been associated with poor motor skill learning in sport and surgery, but it has not yet been examined in dental education. Therefore, the aim of this study was to evaluate the propensity for disruptive reinvestment among dental students so as to optimize their learning needs. Volunteer dental students (210) completed three reinvestment surveys to investigate their self-reported propensity to engage in conscious self-monitoring and control of their movements and decisions. We used analysis of variance (ANOVA), with post-hoc analyses as appropriate, to assess the effect of various participant demographics on their reinvestment scores. Male participants had a lower mean reinvestment scale score than females (p < .05). Older participants were found to have a lower mean movement reinvestment score, compared to younger reinvesters (p < .05). On the other hand, younger reinvesters had a lower mean decision reinvestment score compared to the older age group (p < .05). When compared with participants in previous studies our participants obtained a significantly higher reinvestment score (p < .05). In conclusion, gender and age may be related to dental students' self-reported propensity to reinvest. Moreover, dental students were found to be more self-conscious when compared with individuals who perform gross motor skill tasks. These results provide insight into the acquisition of dental skills that may assist in designing pre-clinical training curriculum in dental education.

Neural Correlates of Motor Skill Learning Are Dependent on Both Age and Task Difficulty

Although a general age-related decline in neural plasticity is evident, the effects of age on neural plasticity after motor practice are inconclusive. Inconsistencies in the literature may be related to between-study differences in task difficulty. Therefore, we aimed to determine the effects of age and task difficulty on motor learning and associated brain activity. We used task-related electroencephalography (EEG) power in the alpha (8–12 Hz) and beta (13–30 Hz) frequency bands to assess neural plasticity before, immediately after, and 24-h after practice of a mirror star tracing task at one of three difficulty levels in healthy younger (19–24 yr) and older (65–86 yr) adults. Results showed an age-related deterioration in motor performance that was more pronounced with increasing task difficulty and was accompanied by a more bilateral activity pattern for older vs. younger adults. Task difficulty affected motor skill retention and neural plasticity specifically in older adults. Older adults that practiced at the low or medium, but not the high, difficulty levels were able to maintain improvements in accuracy at retention and showed modulation of alpha TR-Power after practice. Together, these data indicate that both age and task difficulty affect motor learning, as well as the associated neural plasticity.

Modified sensory feedback enhances the sense of agency during continuous body movements in virtual reality

The sense of agency refers to the feeling of control over one's own actions, and through them, the external events. This study examined the effect of modified visual feedback on the sense of agency over one's body movements using virtual reality in healthy individuals whose motor control was disturbed. Participants moved a virtual object using their right hand to trace a trajectory (Experiment 1) or a leading target (Experiment 2). Their motor control was disturbed by a delay in visual feedback (Experiment 1) or a 1-kg weight attached to their wrist (Experiment 2). In the offset conditions, the virtual object was presented at the median point between the desired position and the participants' actual hand position. In both experiments, participants reported improved sense of agency in the offset condition compared to the aligned condition where the visual feedback reflected their actual body movements, despite their motion being less precise in the offset condition. The results show that sense of agency can be enhanced by modifying feedback to motor tasks according to the goal of the task, even when visual feedback is discrepant from the actual body movements. The present study sheds light on the possibility of artificially enhancing body agency to improve voluntary motor control.

Use of Acoustic Feedback to Change Gait Patterns: Implementation and Transfer to Motor Learning Theory—A Scoping Review

Changing gait parameters through acoustic feedback is a promising approach in gait therapy. The question remains to what extent, if any, the theories and concepts of motor learning have been taken into account for acoustic feedback systems development. Fifteen studies were identified for further analysis using a scoping review framework, among which seven had individuals with disordered gait as their population and eight incorporated healthy individuals. It was found that most studies used error feedback and did not test for long-term effects on gait parameters. It can be concluded that future studies should apply motor learning theories and concepts to the development of acoustic feedback devices for gait therapy.

Effect of errorless learning on the acquisition of fine motor skills in pre-clinical endodontics

This study aimed to evaluate the impact of errorless and errorful learning, on acquisition of root canal hand-instrumentation skills. Dental students prepared standardised canals of different diameters and curvatures. Learning involved minimising (errorless: n = 21) or maximising errors (errorful: n = 21). Students who had completed accredited pre-clinical activities provided comparative data (n = 17). During testing, the distal canal of a plastic mandibular molar was prepared, first as a single task and then under multi-tasking conditions. Performance was assessed by preparation accuracy and time. Differences were assessed using anova (P < 0.05). Performance in the experimental groups was similar during learning. When multi-tasking, errorful learners showed a deterioration in preparation accuracy (P < 0.05). In contrast, preparation accuracy and completion times for the errorless and comparative groups remained stable when multi-tasking. Errorless learning resulted in stable performance under multi-tasking conditions. Investigation of alternative approaches to learning motor skills in dentistry is warranted as such approaches may provide better outcomes, especially under demanding conditions.

Does learning a skill with the expectation of teaching it impair the skill's execution under psychological pressure if the skill is learned with analogy instructions?

OBJECTIVE

Having learners practice a motor skill with the expectation of teaching it (versus an expectation of being tested on it) has been revealed to enhance skill learning. However, this improvement in skill performance is lost when the skill must be performed under psychological pressure due to 'choking under pressure.' The present study will investigate whether this choking effect is caused by an accrual of declarative knowledge during skill practice and could be prevented if a technique (analogy instructions) to minimize the accrual of declarative knowledge during practice is employed.

DESIGN

We will use a 2 (Expectation: teach/test) x 2 (Instruction: analogy/explicit) x 2 (Posttest: high-pressure/low-pressure) mixed-factor design, with repeated measures on the last factor.

METHODS

A minimum of 148 participants will be quasi-randomly assigned (based on sex) to one of four groups. Participants in the teach/analogy and teach/explicit groups will practice golf putting with the expectation of teaching putting to another participant, and analogy instructions or explicit instructions, respectively. Participants in the test/analogy and test/explicit groups will practice golf putting with the expectation of being tested on their putting, and analogy instructions or explicit instructions, respectively. The next day all participants will complete low- and high-pressure putting posttests, with their putting accuracy serving as the dependent variable.

Feasibility and effectiveness of home-based therapy programmes for children with cerebral palsy: a systematic review

OBJECTIVE

To assess the feasibility and effectiveness of home-based occupational therapy and physiotherapy programmes in children with cerebral palsy (CP), focusing on the upper extremity and reporting on child-related and/or parent-related outcomes.

DESIGN

Systematic review.

DATA SOURCES

Electronic searches were performed in MEDLINE, EMBASE, CINAHL, PsycINFO, OTseeker and PEDro, and in ICTRP and CENTRAL trial registers, from inception to 6 June 2019.

ELIGIBLE CRITERIA

The review included all types of original studies concerning feasibility or effectiveness of home-based therapy in children aged <18 years with any type of CP. No language, publication status or publication date restrictions were applied.

DATA EXTRACTION AND SYNTHESIS

Study and intervention characteristics and the demographics of participating children and their parents were extracted. Feasibility was assessed by outcomes related to acceptability, demand, implementation, practicality, adaptation, expansion or integration. Regarding effectiveness, child-related outcome measures related to any level of the International Classification of Functioning, Disability and Health, or parent-related outcomes were investigated. Two authors independently extracted the data. Risk of bias was assessed using the Downs and Black checklist and the Joanna Briggs Institute Critical Appraisal Checklist.

RESULTS

The search resulted in a total of 92 records: 61 studies and 31 conference abstracts. Feasibility studies reported mainly on acceptability and implementation. Overall compliance to home-based training programmes (implementation) was moderate to high, ranging from 56% to 99%. In the effectiveness studies, >40 different child-related outcome measures were found. Overall, an improvement in arm-hand performance within group across time was shown. Only two studies reported on a parent-related outcome measure. No increase in parental stress was found during the intervention.

CONCLUSIONS

Based on the results of the included studies, home-based training programmes seem to be feasible. However, conclusions about the effectiveness of home programmes cannot be made due to the large variability in the study, patient and intervention characteristics, comparators, and outcome measures used in the included studies.

PROSPERO REGISTRATION NUMBER

CRD42016043743.

Ebbinghaus visual illusion: no robust influence on novice golf-putting performance

Do visual illusions reliably improve sports performance? To address this issue, we used procedures inspired by Witt et al. (Psychol Sci 23:397-399, 2012) seminal study, which reported that putting on a miniature golf course was positively influenced by an increase in apparent hole size induced by the Ebbinghaus visual illusion. Because Witt et al.'s motor task-putting golf balls toward a hole from the distance of 3.5 m-was impossible for participants who were novices in golf (Experiment 1a), we decided to shorten the putting distance (i.e., 2 m instead of 3.5 m) in Experiment 1b. Otherwise, this second experiment closely followed every other aspects of Witt et al.'s procedure (i.e., one small or one standard golf hole surrounded by a ring of small or large circles). However, this attempt to replicate Witt et al.'s findings failed: the Ebbinghaus illusion significantly influenced neither hole perception nor putting performance. In two subsequent experiments, we encouraged the emergence of the effect of the illusion by simultaneously presenting both versions of the illusion on the mat. This major adaptation successfully modified the perceived size of the hole but had no impact on putting performance (Experiment 2), even when the putting task was made easier by shortening the putting distance to only 1 m (Experiment 3). In the absence of detectable effects of the illusion on putting performance, we conclude that the effects of visual illusions on novice sports performance do not represent a robust phenomenon.

Designing Junior Sport to Maximize Potential: The Knowns, Unknowns, and Paradoxes of Scaling Sport

In this mini-review, we draw attention to an important yet relatively untapped topic in the developmental pathway - the design of junior sport so that it appropriately matches the functional capacities of children. Junior sport is a regular weekend activity for many children across the world, yet many will be required to prematurely play on a field or with equipment that is designed for adults. Herein lies an opportunity for sport administrators to nurture children's development in sport by appropriately manipulating the rules and dimensions of the game. The aim of this mini-review is to (1) draw attention to the value of scaling junior sport, (2) highlight paradoxes within the current scaling sport literature, and (3) emphasize a way forward for junior sport research. If we are genuine in our endeavor to tailor sports experiences for children, more sophisticated approaches to scaling those experiences are a must.

Audiohaptic Feedback Enhances Motor Performance in a Low-Fidelity Simulated Drilling Task

When used in educational settings, simulations utilizing virtual reality (VR) technologies can reduce training costs while providing a safe and effective learning environment. Tasks can be easily modified to maximize learning objectives of different levels of trainees (e.g., novice, intermediate, expert), and can be repeated for the development of psychomotor skills. VR offers a multisensory experience, providing visual, auditory, and haptic sensations with varying levels of fidelity. While simulating visual and auditory stimuli is relatively easy and cost-effective, similar representations of haptic sensation still require further development. Evidence suggests that mixing high- and low-fidelity realistic sensations (e.g., audition and haptic) can improve the overall perception of realism, however, whether this also leads to improved performance has not been examined. The current study examined whether audiohaptic stimuli presented in a virtual drilling task can lead to improved motor performance and subjective realism, compared to auditory stimuli alone. Right-handed participants (n = 16) completed 100 drilling trials of each stimulus type. Performance measures indicated that participants overshot the target during auditory trials, and undershot the target during audiohaptic trials. Undershooting is thought to be indicative of improved performance, optimizing both time and energy requirements.

The Effect of Gradual Self-Control of Task Difficulty and Feedback on Learning Golf Putting

Purpose: This study aimed to examine the effect of gradual self-control of task difficulty and feedback on accuracy and movement pattern of the golf putting sport skill. Method: Sixty students were quasi-randomly assigned to four groups under a varying combination of the two factors of task difficulty control (self-controlled or yoked) and feedback control (self-controlled or yoked). The participants in the two groups (dual-factor gradual self-control and self-controlled task difficulty group) that granted control over task difficulty in the acquisition phase were told they could choose any of the pre-set distances from the target. All groups were given 100% feedback in the first half of the acquisition phase, but the participants in the two groups (dual-factor gradual self-control group and self-controlled feedback) that could control their feedback were told that in the second half of the acquisition phase they would be able to ask for feedback when needed. The practice schedule of each member of the dual-factor gradual self-control group was used as a basis to plan the practice of predetermined distances and feedback presentation to the corresponding participants in the yoked conditions. Results: ANOVA with repeated measures showed that the practice method involving gradual self-control of two factors had a positive impact on accuracy and movement pattern of golf putting in the retention and transfer tests compared to other methods (p_s < .05). Conclusion: The advantages of self-control practice presumably come from better adjustment of challenge points by the learner in the course of the practice.

Domain-Specific Working Memory, But Not Dopamine-Related Genetic Variability, Shapes Reward-Based Motor Learning

The addition of rewarding feedback to motor learning tasks has been shown to increase the retention of learning, spurring interest in its possible utility for rehabilitation. However, motor tasks using rewarding feedback have repeatedly been shown to lead to great interindividual variability in performance. Understanding the causes of such variability is vital for maximizing the potential benefits of reward-based motor learning. Thus, using a large human cohort of both sexes (n = 241), we examined whether spatial (SWM), verbal, and mental rotation (RWM) working memory capacity and dopamine-related genetic profiles were associated with performance in two reward-based motor tasks. The first task assessed the participant's ability to follow a slowly shifting reward region based on hit/miss (binary) feedback. The second task investigated the participant's capacity to preserve performance with binary feedback after adapting to the rotation with full visual feedback. Our results demonstrate that higher SWM is associated with greater success and an enhanced capacity to reproduce a successful motor action, measured as change in reach angle following reward. In contrast, higher RWM was predictive of an increased propensity to express an explicit strategy when required to make large reach angle adjustments. Therefore, SWM and RWM were reliable, but dissociable, predictors of success during reward-based motor learning. Change in reach direction following failure was also a strong predictor of success rate, although we observed no consistent relationship with working memory. Surprisingly, no dopamine-related genotypes predicted performance. Therefore, working memory capacity plays a pivotal role in determining individual ability in reward-based motor learning.SIGNIFICANCE STATEMENT Reward-based motor learning tasks have repeatedly been shown to lead to idiosyncratic behaviors that cause varying degrees of task success. Yet, the factors determining an individual's capacity to use reward-based feedback are unclear. Here, we assessed a wide range of possible candidate predictors, and demonstrate that domain-specific working memory plays an essential role in determining individual capacity to use reward-based feedback. Surprisingly, genetic variations in dopamine availability were not found to play a role. This is in stark contrast with seminal work in the reinforcement and decision-making literature, which show strong and replicated effects of the same dopaminergic genes in decision-making. Therefore, our results provide novel insights into reward-based motor learning, highlighting a key role for domain-specific working memory capacity.

Rowing Simulator Modulates Water Density to Foster Motor Learning

Although robot-assisted training is present in various fields such as sports engineering and rehabilitation, provision of training strategies that optimally support individual motor learning remains as a challenge. Literature has shown that guidance strategies are useful for beginners, while skilled trainees should benefit from challenging conditions. The Challenge Point Theory also supports this in a way that learning is dependent on the available information, which serves as a challenge to the learner. So, learning can be fostered when the optimal amount of information is given according to the trainee's skill. Even though the framework explains the importance of difficulty modulation, there are no practical guidelines for complex dynamic tasks on how to match the difficulty to the trainee's skill progress. Therefore, the goal of this study was to determine the impact on learning of a complex motor task by a modulated task difficulty scheme during the training sessions, without distorting the nature of task. In this 3-day protocol study, we compared two groups of naïve participants for learning a sweep rowing task in a highly sophisticated rowing simulator. During trainings, groups received concurrent visual feedback displaying the requested oar movement. Control group performed the task under constant difficulty in the training sessions. Experimental group's task difficulty was modulated by changing the virtual water density that generated different heaviness of the simulated water-oar interaction, which yielded practice variability. Learning was assessed in terms of spatial and velocity magnitude errors and the variability for these metrics. Results of final day tests revealed that both groups reduced their error and variability for the chosen metrics. Notably, in addition to the provision of a very well established visual feedback and knowledge of results, experimental group's variable training protocol with modulated difficulty showed a potential to be advantageous for the spatial consistency and velocity accuracy. The outcomes of training and test runs indicate that we could successfully alter the performance of the trainees by changing the density value of the virtual water. Therefore, a follow-up study is necessary to investigate how to match different density values to the skill and performance improvement of the participants.

A Transcranial Stimulation Intervention to Support Flow State Induction

Background: Flow states are considered a positive, subjective experience during an optimal balance between skills and task demands. Previously, experimentally induced flow experiences have relied solely on adaptive tasks. Objective: To investigate whether cathodal transcranial direct current stimulation (tDCS) over the left dorsolateral prefrontal cortex (DLPFC) area and anodal tDCS over the right parietal cortex area during video game play will promote an increased experience of flow states. Methods: Two studies had participants play Tetris or first-person shooter (FPS) video games while receiving either real tDCS or sham stimulation. Tetris recruited 21 untrained players who infrequently played video games while the 11 FPS participants played FPS frequently. Flow experience was assessed before and after stimulation. Results: Compared to sham stimulation, real stimulation increased flow experience for both untrained Tetris and trained FPS players. Improved performance effects were only seen with untrained groups. Conclusion: Cathodal and anodal tDCS over the left DLPFC and right parietal areas, respectively may encourage flow experiences in complex real-life motor tasks that occur during sports, games, and everyday life.

Dissociative effects of normative feedback on motor automaticity and motor accuracy in learning an arm movement sequence

Within a pre-post-design, we scrutinized the effects of normative augmented feedback with positive and negative valence on learning motor accuracy, consistency as well as automaticity by means of a dual-task paradigm. Forty-two healthy physical education students were instructed to produce an arm-movement sequence as precisely as possible with regard to three spatial reversal points within a time limit of 1200 ms. Twenty-eight practiced an elbow-extension-flexion-sequence (690 trials) and 14 participants were tested as a control group without feedback practice. Valence of normative feedback was systematically manipulated by means of reference lines in a visual feedback display. The reference lines indicated performance of a putative peer-group either to be superior (negative valence, Normative-Negative-Group) or inferior (positive valence, Normative-Positive-Group) to participants' actual performance. As a result, dual-task costs (n-back error) significantly decreased solely in the Normative-Positive-Group, p = .003, η²_p = .51, but in no other group. Surprisingly, the mean absolute error for the motor task significantly decreased (i.e., precision increased) only in the Normative-Negative-Group with a large effect size, but in none of the other groups. Motor consistency was not significantly affected by the valence of normative feedback. According to the hypotheses of error-provoked attentional control, positive feedback-valence appears to enhance skill automatization, while - unexpectedly - only negative feedback-valence seems to enhance movement precision, which may be explained by effects of feedback valence on the learners aspiration level.

Effects of Error Experience on Learning to Lower Speech Nasalance Level

Purpose This research aims to examine the effects of error experience when learning to speak with lowered nasalance level. Method A total of 45 typical speakers were instructed to learn to lower speech nasalance level in either an errorless (restricted possibility for committing errors) or an errorful (unrestricted possibility for committing errors) learning condition. The nasality level of the participants' speech was measured by a nasometer and quantified by nasalance scores (in percent). Errorless learners practiced producing speech with lowered nasalance level with a threshold nasalance score of 50% (the easiest target) at the beginning, which gradually decreased to a threshold of 10% (the most difficult target) at the end. The same set of threshold targets was presented to errorful learners, but in reverse order. Errors were defined by the proportion of speech, with a nasalance score exceeding the threshold. Retention and transfer tests were administered. Results Errorless learners displayed fewer errors and lower mean nasalance scores than errorful learners during the acquisition phase. Furthermore, errorless learners achieved lower mean nasalance scores than errorful learners in the retention and transfer tests. Conclusion These results suggest that errorless learning is more effective than errorful learning and that error experience has a detrimental effect on the acquisition of a novel speech motor task that requires minimization of the nasality level. Errorless learning may be a useful paradigm for the intervention and management of hypernasality in clinical settings where behavioral treatments are needed.