Visual illusions can facilitate sport skill learning

Motivation Unraveled: Giving Choice to Football Players to Improve Anterior Cruciate Ligament Injury Prevention

ABSTRACT

Benjaminse, A, Nijmeijer, EM, Gokeler, A, Broekhaar, DC, and Cortes, N. Motivation unraveled: giving choice to football players to improve anterior cruciate ligament injury prevention. J Strength Cond Res XX(X): 000-000, 2024-Providing athletes some control over a training session facilitates motor skill acquisition. This is a promising concept to use in anterior cruciate ligament (ACL) injury prevention, as the key for risk reduction is to improve quality of movement. The goal of this study was to better understand why improved motor learning occurred when football players had the opportunity to choose when to receive feedback when practicing sidestep cutting (SSC) movements. Healthy male recreational football players (n = 22, 22.9 ± 1.7 years, 185.5 ± 7.2 cm, 79.3 ± 9.2 kg) were included and assigned to the self-control (SC) or the yoked (YK) group. The players performed anticipated and unanticipated SSC. They received video instructions and were instructed to "copy the movement of the model to the best of their ability." During the training blocks, the SC group could ask for feedback, whereas the YK group could not. Cutting movement assessment scores (CMAS) were measured to test quality of movement and the Intrinsic Motivation Inventory was administered to measure constructs of motivation. In the anticipated condition, SC group showed better scores in immediate post and the retention test compared with pretest (p < 0.001), whereas the YK group showed worse scores in the retention test compared with immediate posttest (p = 0.001). Perceived competence (p = 0.017) and self-efficacy (p = 0.032) were consistent factors that correlated with improved CMAS in the SC group. This has given us innovative insights into underlying mechanisms optimizing the quality of movement, necessary to improve current ACL injury prevention approaches.

The effect of a visual illusion and self-controlled practice on motor learning in children at risk for developmental coordination disorder

Numerous efforts have been made to test the OPTIMAL theory of motor learning in healthy children and adult populations. However, only a small number of studies have tested this theory in children with cognitive-motor disorders, such as developmental coordination disorder (DCD). The present study aims to examine the individual and additive effects of a visual illusion and self-controlled practice on a golf putting task in children at risk for DCD based on the OPTIMAL theory. Forty children at risk for DCD (mean age = 8.57 ± 1.05 years) were randomly assigned to four experimental groups (1-small visual illusion + self-controlled practice; 2-big visual illusion + self-controlled practice; 3-small visual illusion + yoked; 4-big visual illusion + yoked). Following 12 pretest trials of a golf putting task, the participants completed 5 blocks of 12 trials of practice on the first day. A retention test (12 trials) and a transfer dual-task test (12 trials) were conducted on the second day. The results indicated that in retention test the big visual illusion + self-controlled practice group was significantly better than the small visual illusion + yoked group (p = 0.01), while there was not any other significant difference between groups at retention test as well as between all groups at practice phase and transfer test (p > 0.05 for all comparisons). In other words, an additive effect has been observed just in the retention test but not the practice phase as well as transfer test. In general, the results of this study support the OPTIMAL theory of motor learning in children at risk for DCD and suggests to all educators who work with these children to use the combination of the visual illusion with self-controlled practice to improve the motor learning of children at risk for DCD.

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.

A goal-centric outlook on learning

Goals play a central role in human cognition. However, computational theories of learning and decision-making often take goals as given. Here, we review key empirical findings showing that goals shape the representations of inputs, responses, and outcomes, such that setting a goal crucially influences the central aspects of any learning process: states, actions, and rewards. We thus argue that studying goal selection is essential to advance our understanding of learning. By following existing literature in framing goal selection within a hierarchy of decision-making problems, we synthesize important findings on the principles underlying goal value attribution and exploration strategies. Ultimately, we propose that a goal-centric perspective will help develop more complete accounts of learning in both biological and artificial agents.

Enhanced expectancies benefit performance under distraction, but compromise it under stress: Exploring the OPTIMAL theory

Motor learning can benefit from practice under enhanced expectancies; that is, the belief one can generate an intended positive outcome. According to the OPTIMAL (Optimizing Performance Through Intrinsic Motivation and Attention for Learning) theory, this benefit manifests from a greater coupling between action and its external consequences, which potentially coincides with a more automatic mode of control. The aim of the study was to examine this possibility, and in so doing, understand more about the psycho-motor processes underpinning the influence of expectancies. On Day 1, novice participants practiced a dart-throwing task under enhanced (EE) (n = 11), reduced (RE) (n = 12) or no (control; CTL) (n = 12) expectancies. Enhanced and reduced expectancies were indirectly manipulated by positively reinforcing shots that landed within the large or small circle on the dartboard, respectively. On Day 2, participants transferred to a dual-task (i.e., tone-counting) or stress (i.e., social-comparative threat, false feedback) setting. While there was no evidence of improvement across practice, RE was significantly worse than CTL for the dual-task, but EE was significantly worse than RE and CTL under stress (ps < 0.05). Therefore, the ability of EE to retain performance within the dual-task, but decline under stress, suggests a more automatic mode of control was adopted. Both theoretical and practical implications are discussed.

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.

Both Sensorimotor Rhythm Neurofeedback and Self-Controlled Practice Enhance Motor Learning and Performance in Novice Golfers

A major concern voiced by motor behavior scientists is to find useful practice techniques that can be effective in improving motor learning and performance. Neurofeedback and self-controlled practice are among the techniques that have recently drawn attention from specialists in this area. The present study examined the additive and individual effects of sensorimotor rhythm (SMR) neurofeedback as well as self-controlled practice on motor learning and performance in novice golfers. In this semi-empirical study, forty adults (20 females, Meanage = 26.10, SD = 5.56 years) were conveniently selected and randomly assigned to four groups: (1) neurofeedback/self-controlled practice, (2) neurofeedback/yoked practice, (3) sham/self-controlled practice, and (4) sham/yoked practice. The participants performed golf putting task in four stages, namely pretest (12 trials), intervention (one day after pretest; 6 sessions, 36 trails each), post-test (one day after intervention; 12 trials), and follow-up (two weeks after interventions; 12 trials). In addition, the participants had their EEG (SMR wave in Cz point) recorded during pretest, post-test, and follow-up. The results indicated that, although no additive effect was observed for the two practices during different stages of the experiment (p > 0.05), in acquisition and post-test stages, SMR neurofeedback and self-controlled practice independently facilitated golf putting (p ≤ 0.05). However, in the follow-up test, only the neurofeedback practice maintained its positive effects (p ≤ 0.05). The results also showed that participation in SMR neurofeedback practice can enhance the power of the SMR wave (p ≤ 0.05), regardless of the type of the self-controlled practice used. In sum, the two practice techniques seem to be independently effective in facilitating motor learning in instructional settings, particularly for golfers.

Size Perception of a Sport Target as a Function of Practice Success Conditions

Superior motor task success has been correlated with participants’ self-reports of a larger-than-actual size of a sport-related target. In the present study, we examined whether a putting practice condition with greater success would differentially impact participants’ self-reported perceptions of the size of the putting hole during acquisition and retention. We randomly assigned participants to one of three different practice conditions (success-early, success-late, and self-controlled success) and had them self-report their perceived size of the putting hole upon completion of each required putting distance (25, 50, 75, 100, 125, 150, 175, 200 cm). Although there were no statistically significant differences between motor task success in the acquisition or retention period for the practice conditions, self-reported perceptions of target size were impacted by practice condition. During the acquisition period, participants in the self-controlled success and success-late conditions self-reported that the putting hole was larger than did participants in the success-early condition. In the retention period, participants in the self-controlled success condition perceived the target as larger than those in the success-early condition. These findings are the first to show that practice condition, independent of task success, differentially impacted self-reported perception of a target size.

The Effect of Large Visual Illusion and External Focus of Attention on Gaze Behavior and Learning of Dart Throw Skill

Research has shown that large visual illusions and an external focus of attention can improve novice’s motor learning. However, the combined effects of these approaches and the underlying mechanisms have yet to be studied. Therefore, the present study examined the effects of a large visual illusion and an external focus on the learning of a dart throwing task in novices and measured the perceptual mechanisms underpinning learning using quiet eye. Forty novice participants were randomly divided into four groups: large visual illusion, external focus of attention, combined large visual illusion and external focus of attention, and control group. The study consisted of a pretest, a practice phase, an immediate retention test, a 24-hr retention test, and a transfer test. Results revealed that all groups increased throwing accuracy and quiet eye duration from pretest to immediate retention. In the immediate retention, 24-hr retention, and transfer test, large visual illusion had greater accuracy and longer quiet eye duration than the control group. In addition, there were no significant differences between the visual illusion and external focus groups for throwing accuracy and quiet eye duration. The findings suggest that combining large visual illusion and external focus can independently improve motor learning but combining these manipulations does not have additive benefits.

The recommendation for learners to be provided with control over their feedback schedule is questioned in a self-controlled learning paradigm

Evidence that self-controlled feedback schedules are more effective for motor learning than yoked or predetermined schedules has been used to forward the recommendation that practitioners should provide choice to learners over when they would like to receive feedback. This recommendation can be questioned because the typical comparison groups in such experimentation do not well represent the applied setting. Consequently, comparison groups that better map onto the applied setting are needed. To this end, three groups learned a golf putting task: (1) self-controlled, (2) traditional-yoked, and (3) a group who were led to believe their KR schedule was being controlled by a golf coach. Participants (N = 60) completed a pre-test, acquisition phase, and delayed post-tests (retention/transfer). No group differences during the post-tests for mean radial error, F(2, 54) = 2.71, p = .075, or bivariate variable error, F(2, 56) = 0.11, p = .896, were found. Thus, the typical self-controlled learning advantage was not observed. Given the failure to replicate self-controlled benefits, combined with the fact there is little research that has directly compared self-controlled feedback schedules to coach-controlled schedules, we argue more evidence is needed before advocating that learners be provided choice over their feedback schedule.

Translating Thoughts Into Action: Optimizing Motor Performance and Learning Through Brief Motivational and Attentional Influences

Skilled motor performance is essential in sports, the performing arts, various occupations, and many daily activities. Scientists and practitioners alike are therefore interested in understanding the conditions that influence the performance and learning of movement skills, and how they can be utilized to optimize training. In OPTIMAL theory, three motivational and attentional factors are key: enhanced expectancies for future performance, the performer’s autonomy, and an external focus of attention. We review recent evidence suggesting that each factor contributes independently to strengthen the coupling of goals to actions. This work has implications ranging from fostering more effective skill development in novice learners, to increasing the efficiency of athletes’ and musicians’ performance, and to facilitating the success of patients in regaining functional capabilities.

Easy Task and Choice: Motivational Interventions Facilitate Motor Skill Learning in Children

Expectancies for success and autonomy support have been shown to facilitate motor learning and enhance motor performance. The purpose of the study was to examine whether we replicated (a) enhanced expectancies and autonomy support intervention enhanced motor skill learning in children, and (b) identified the underlying psychological mechanism. Sixty children kicked soccer balls with their dominant leg to a squared area target. Participants were randomly assigned to one of the four groups: enhanced expectancies and autonomy support (EE/AS), enhanced expectancies (EE), autonomy support (AS), or control (CON) groups. Participants learning the skill were or were not provided enhanced expectation instructions by making the task success easier and provided an opportunity to choose one of the three colored balls during their practice. Two days later, they performed retention and transfer tests. Results indicated that the EE/AS group had the highest scores, with main effects of autonomy support being significant and enhanced expectancies being marginally significant for the retention test and significant for the transfer test. The EE/AS group had the highest self-efficacy and perceived choice scores. Therefore, having high expectancies for success and being autonomous were important ingredients for facilitating motor skill learning in children.

Relatively Easy Criteria for Success Enhances Motor Learning by Altering Perceived Competence

The purpose of this study was to examine whether enhancing success expectation by providing relatively easy criteria for success would, in turn, enhance motor learning outcomes. Thirty university student participants threw soft-golf balls towards a circular target, using their non-dominant arm; they performed seven blocks of 12 trials from a distance of 5.5 meters on Day 1, and one block of 12 trials on separate retention and transfer tests on Day 2. After the first block on Day 1, participants were randomly assigned to one of two groups in which they practiced the remaining six blocks of 12 trials: (a) one with relatively easy success (RES) criteria or (b) one with difficult success (DS) criteria. After the practice, we administered a perceived competence scale, a sub-scale of the Intrinsic Motivation Inventory (IMI). On Day 2, participants in the RES group outperformed those in the DS group on both the retention and transfer tests, showing enhanced motor learning. The RES group also self-reported higher perceived competence than the DS group, indicating that the mechanism for benefiting from easier success criteria may have been an alteration in participants' perceived competence.

A tale of too many tasks: task fragmentation in motor learning and a call for model task paradigms

Motor learning encompasses a broad set of phenomena that requires a diverse set of experimental paradigms. However, excessive variation in tasks across studies creates fragmentation that can adversely affect the collective advancement of knowledge. Here, we show that motor learning studies tend toward extreme fragmentation in the choice of tasks, with almost no overlap between task paradigms across studies. We argue that this extreme level of task fragmentation poses serious theoretical and methodological barriers to advancing the field. To address these barriers, we propose the need for developing common 'model' task paradigms which could be widely used across labs. Combined with the open sharing of methods and data, we suggest that these model task paradigms could be an important step in increasing the robustness of the motor learning literature and facilitate the cumulative process of science.

Knowledge of Results do not Affect Self-Efficacy and Skill Acquisition on an Anticipatory Timing Task

The literature provides that self-efficacy increases if individuals receive more information of their success during practice with a consequent increase in learning outcomes. The objective of this study was to test the effects of different knowledge of results (KR) frequencies on self-efficacy and motor learning. Two groups with different KR frequencies performed an anticipatory timing task on two consecutive days. To measure self-efficacy, a questionnaire on participant's efficacy was applied at different times. Both groups increased self-efficacy during practice, but we found no evidence of the effect of performance on self-efficacy and no group and self-efficacy effect on retention. These findings demonstrate that different KR frequencies do not affect the self-efficacy and learning of an anticipatory timing task.

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.

Visual Illusions Affect Motor Performance, But not Learning in Highly Skilled Shooters

Enhanced expectancies are an important component of OPTIMAL theory and are thought to contribute to motor performance and learning. There is limited information, however, on the generalizability of OPTIMAL theory to highly skilled individuals. The purpose of this study was to examine the effects of visual illusions, specifically an Ebbinghaus illusion, on the performance and learning of an aiming task using highly skilled 10-m rifle and pistol shooters. Two groups of shooters with international experience were recruited and practiced with perceived larger and smaller targets. Our results indicated that participants who perceived the target larger reported higher self-efficacy immediately after practice. In addition, these participants had higher shooting performance during practice. Our retention test (24 hours later), however, did not produce differences in self-efficacy or shooting performance. Our data suggests that visual illusions are beneficial for motor performance in highly skilled shooters, but may not affect learning in those who are in the latter stages of learning. Further studies should continue examining the role of visual illusions for enhancing expectancies in highly skilled and experienced performers.

Is the Ebbinghaus illusion a size contrast illusion?

The Ebbinghaus illusion, in which a central target surrounded by larger context figures looks smaller than when surrounded by smaller context figures, is usually classified as a size contrast illusion. Thus "size contrast" is the dominant account of this effect. However, according to an alternative "contour interaction" account this phenomenon has little to do with size contrast but is rather caused by distance-dependent attractive and repulsive interactions between neural representation of contours. Here evidence is presented against the size contrast account and consistent with the contour interaction account. Experiment 1 was a control study confirming that the illusion can be obtained using displays consisting only of squares, which are more convenient to manipulate than the standardly used circles. In Experiment 2, the standard configuration involving small context figures surrounding the target was compared to a novel configuration, which involved many "spread" small context figures. The illusory effect of the standard context was stronger than the illusory effect of the spread context, in accord with the prediction of the contour interaction account, and contrary to the prediction of the size contrast account. In Experiment 3 two novel configurations were used, based on standard and spread contexts. The results were in accord with the prediction of the contour interaction account, whereas the size contrast account had no prediction because the stimuli did not involve conventional size contrast. Additional aspects of the stimuli and an account of the illusion based on a perspective interpretation are also discussed.

Perceptual Modification of the Built Environment to Influence Behavior Associated with Physical Activity: Quasi-Experimental Field Studies of a Stair Banister Illusion

BACKGROUND

Re-engineering the built environment to influence behaviors associated with physical activity potentially provides an opportunity to promote healthier lifestyles at a population level. Here we present evidence from two quasi-experimental field studies in which we tested a novel, yet deceptively simple, intervention designed to alter perception of, and walking behavior associated with, stairs in an urban area.

OBJECTIVES

Our objectives were to examine whether adjusting a stair banister has an influence on perceptions of stair steepness or on walking behavior when approaching the stairs.

METHODS

In study 1, we asked participants (n = 143) to visually estimate the steepness of a set of stairs viewed from the top, when the stair banister was adjusted so that it converged with or diverged from the stairs (± 1.91°) or remained neutral (± 0°). In study 2, the walking behavior of participants (n = 36) was filmed as they approached the stairs to descend, unaware of whether the banister converged, diverged, or was neutral.

RESULTS

In study 1, participants estimated the stairs to be steeper if the banister diverged from, rather than converged with, the stairs. The effect was greater when participants were unaware of the adjustment. In study 2, walking speed was significantly slower when the banister diverged from, rather than converged with, the stairs.

CONCLUSIONS

These findings encourage us to speculate about the potential to economically re-engineer features of the built environment to provide opportunities for action (affordances) that invite physical activity behavior or even promote safer navigation of the environment.

Action potential influences spatial perception: Evidence for genuine top-down effects on perception

The action-specific account of spatial perception asserts that a perceiver's ability to perform an action, such as hitting a softball or walking up a hill, impacts the visual perception of the target object. Although much evidence is consistent with this claim, the evidence has been challenged as to whether perception is truly impacted, as opposed to the responses themselves. These challenges have recently been organized as six pitfalls that provide a framework with which to evaluate the empirical evidence. Four case studies of action-specific effects are offered as evidence that meets the framework's high bar, and thus that demonstrates genuine perceptual effects. That action influences spatial perception is evidence that perceptual and action-related processes are intricately and bidirectionally linked.