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-Perceived target size at baseline (pre-practice), at the end of practice (postpractice), and before the retention test, as a function of the type of visual illusion (target perceived as small vs. target perceived as large).
Source publication
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 illus...
Citations
... Beyond an external focus of attention, autonomy support and enhanced expectancies are the two motivational tenets of the OPTIMAL theory (Wulf & Lewthwaite, 2016). Using these motor learning techniques to improve performance outcomes has been robustly supported in the literature (Bahmani et al., 2018), but support for their use in improving specific biomechanical, injury-related risk factors has been limited. Specifically, employing real-time visual biofeedback mitigated high-risk biomechanics (Bonnette et al., 2019), and delivering simple EE and AS instructions improved postural balance measures (Chua et al., 2020). ...
Our purpose in this study was to determine the effects of a virtual reality intervention delivering specific motivational motor learning manipulations of either autonomy support (AS) or enhanced expectancies (EE) on frontal plane single-leg squatting kinematics. We allocated 45 participants (21 male, 24 female) demonstrating knee, hip, and trunk frontal plane mechanics associated with elevated anterior cruciate ligament injury risk to one of three groups (control, AS, or EE). Participants mimicked an avatar performing five sets of eight repetitions of exemplary single-leg squats. AS participants were given the added option of choosing the color of their avatar. EE participants received real-time biofeedback in the form of green highlights on the avatar that remained on as long as the participant maintained pre-determined ‘safe’ frontal plane mechanics. We measured peak frontal plane knee, hip, and trunk angles before (baseline) and immediately following (post) the intervention. The control group demonstrated greater increases in knee abduction angle (Δ = +2.3°) than did the AS (Δ = +0.1°) and EE groups (Δ = −0.4°) ( p = .003; η ² p = .28). All groups demonstrated increased peak hip adduction ( p = .01, η p ² = .18) (control Δ = +1.5°; AS Δ = +3.2°; EE Δ = +0.7°). Hip adduction worsened in all groups. AS and EE motivation strategies appeared to mitigate maladaptive frontal plane knee mechanics.
... In other words, while MI moderation effects could result from lacking certain MI ability, high overall MI abilities may allow individuals to use attention in a more flexible manner. Second, although, like many previously published pistol-shooting-related work [51,67,68], our measure of shot accuracy may not have been granular enough to detect subtle and small changes in motor performance (see Fischman, 2015). Adding complementary measures, such as 'performance consistency' may better detect performance outcomes using attentional focus and MI manipulations. ...
Motor imagery (MI) has emerged as an individual factor that may modulate the effects of attentional focus on motor skill performance. In this study, we investigated whether global MI, as well as its components (i.e., kinesthetic MI, internal visual MI, and external visual MI) moderate the effect of attentional focus on performance in a group of ninety-two young adult novice air-pistol shooters (age: M = 21.87, SD = 2.54). After completing the movement imagery questionnaire-3 (MIQ-3), participants were asked to complete a pistol shooting experiment in three different attentional focus conditions: (1) No focus instruction condition (control condition with no verbal instruction) (2) an internal focus instruction condition, and (3) an external focus condition. Shot accuracy, performance time, and aiming trace speed (i.e., stability of hold or weapon stability) were measured as the performance variables. Results revealed that shot accuracy was significantly poorer during internal relative to control focus condition. In addition, performance time was significantly higher during external relative to both control and internal condition. However, neither global MI, nor its subscales, moderated the effects of attentional focus on performance. This study supports the importance of attentional focus for perceptual and motor performance, yet global MI and its modalities/perspectives did not moderate pistol shooting performance. This study suggests that perception and action are cognitively controlled by attentional mechanisms, but not motor imagery. Future research with complementary assessment modalities is warranted to extend the present findings.
... However, the present findings were inconsistent with some studies (Bahmani et al., 2018;Cañal-Bruland et al., 2016;Maquestiaux et al., 2021). For example, Cañal-Bruland et al. (2016) revealed that the small visual illusion group improved performance from pretest to posttest, whereas large visual illusion group did not show any improvements on marble shooting. ...
... Thus, there may have been little opportunity for improvement in the large illusion condition suggesting that implicit manipulations of success should provide sufficient challenge for learning to occur (Guadagnoli & Lee, 2004;Wulf & Lewthwaite, 2016). Additionally, Bahmani et al. (2018) found that highly skilled rifle and pistol shooters in large perceptual targets group had (Ahead of Print) more accurate performance and more confidence than small perceptual targets group immediately after practice. However, in the retention test with no visual illusions, there were no differences between the two groups further suggesting that visual illusions require adequate challenge for learning to occur and enhancing expectancies alone (i.e., those that enhance perceptions of success) is not sufficient for motor learning (Hodges & Lohse, 2022). ...
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.
... Though comprehensive data on the various forms of EE are lacking, the provision of EE as positive feedback has been demonstrated to improve learner motivation and self-efficacy. 28 This is arguably an important consideration, as fear of reinjury is the most commonly cited reason for not returning to play following ACL injury. 29 Of note, provision of general kinematic feedback, not necessarily positive, has previously been shown to attenuate high-risk lower-extremity biomechanics. ...
Context:
An Optimizing Performance through Intrinsic Motivation and Attention for Learning theory-based motor learning intervention delivering autonomy support and enhanced expectancies (EE) shows promise for reducing cognitive-motor dual-task costs, or the relative difference in primary task performance when completed with and without a secondary cognitive task, that facilitate adaptive injury-resistant movement response. The current pilot study sought to determine the effectiveness of an autonomy support versus an EE-enhanced virtual reality motor learning intervention to reduce dual-task costs during single-leg balance.
Design:
Within-subjects 3 × 3 trial.
Methods:
Twenty-one male and 24 female participants, between the ages of 18 and 30 years, with no history of concussion, vertigo, lower-extremity surgery, or lower-extremity injuries the previous 6 months, were recruited for training sessions on consecutive days. Training consisted of 5 × 8 single-leg squats on each leg, during which all participants mimicked an avatar through virtual reality goggles. The autonomy support group chose an avatar color, and the EE group received positive kinematic biofeedback. Baseline, immediate, and delayed retention testing consisted of single-leg balancing under single- and dual-task conditions. Mixed-model analysis of variances compared dual-task costs for center of pressure velocity and SD between groups on each limb.
Results:
On the right side, dual-task costs for anterior-posterior center of pressure mean and SD were reduced in the EE group (mean Δ = -51.40, Cohen d = 0.80 and SD Δ = -66.00%, Cohen d = 0.88) compared with the control group (mean Δ = -22.09, Cohen d = 0.33 and SD Δ = -36.10%, Cohen d = 0.68) from baseline to immediate retention.
Conclusions:
These findings indicate that EE strategies that can be easily implemented in a clinic or sport setting may be superior to task-irrelevant AS approaches for influencing injury-resistant movement adaptations.
... Of the 56 effect sizes included in the meta-analysis, 16 represent manipulations of feedback after good trials, 13 represent manipulations of perceived task difficulty, 15 represent manipulations of comparative feedback, 7 represent manipulations of conceptions of ability, 4 represent manipulations of extrinsic rewards/punishments, and 2 represent manipulations of self-modeling 2 . The effect sizes composing this metaanalysis were extracted from data pertaining to young adults (n = 34), older adults (n = 6), children and adolescents (n = 13), and special populations (n = 3) consisting of adults with a disability in at least one upper or lower extremity (Bahmani et al., 2018), adults with Parkinson's disease (Chung et al., 2020), and autistic children (Navaee et al., 2018). Most of the effect sizes refer to a 24-hr retention test (n = 44), whereas the remaining refer to a retention test carried out between 24-hr and one week after the acquisition phase (n = 7), or to a retention test carried out at least one week after the acquisition phase (n = 5). ...
... We did not find evidence to support the benefits of enhanced expectancies for special populations (p = .231), which in the present meta-analysis consist of adults with a disability in at least one upper or lower extremity(Bahmani et al., 2018), adults with Parkinson's disease(Chung et al., 2020), and children with autism (Navaee et al., 2018).However, only three studies examined these populations, preventing reliable estimates of effects in them. Future research should investigate the effect of enhanced expectancies on motor learning in these populations. ...
The OPTIMAL theory of motor learning predicts enhanced expectancies facilitate learning. This meta-analysis investigated this prediction by quantifying effect sizes from studies manipulating feedback after good trials, comparative feedback, perceived task difficulty, conceptions of ability, self-modeling, or extrinsic rewards, and assessing learning. After searching databases, 48 studies met inclusion criteria for quantitative analysis. Fifty-six effect sizes were calculated from performance differences between enhanced expectancies and neutral/diminished expectancies groups at delayed retention tests. Results revealed a Hedges’ g = 0.54 (95% CI [0.38, 0.69]) that may be overestimated due to small-study effects and underpowered studies. Moderator analyses revealed feedback after good trials, comparative feedback, perceived task difficulty, and conceptions of ability manipulations significantly improved learning. Few studies used other manipulations, precluding reliable estimates of their effects. Further, significant effects of enhanced expectancies were shown for children/adolescents, young adults, and older adults. Few studies examined special populations, preventing a reliable effect estimate. Finally, the effect of enhanced expectancies on learning was not affected by type of comparison group (neutral/diminished expectancies). Findings suggest enhanced expectancies may facilitate motor learning, consistent with OPTIMAL theory, but pre-registered/registered reports and more powerful studies should be conducted to confirm the effect and estimate its size more accurately.
... Enhanced expectancies can also be achieved by manipulating an individual's perception of task difficulty such that it is perceived easier [11,12,32,34,163,231] and/or altering the criterion for success by providing easier objectives earlier in practice [213]. For instance, youth and adult target-aiming performance and learning is improved when participants aim towards a target that appears larger by surrounding it with smaller targets to manipulate the perception of its size [11,12,34,163]. ...
... Enhanced expectancies can also be achieved by manipulating an individual's perception of task difficulty such that it is perceived easier [11,12,32,34,163,231] and/or altering the criterion for success by providing easier objectives earlier in practice [213]. For instance, youth and adult target-aiming performance and learning is improved when participants aim towards a target that appears larger by surrounding it with smaller targets to manipulate the perception of its size [11,12,34,163]. However, similar to the caution required if implementing social-comparative feedback, the potentially beneficial motor performance/learning effects when providing false positive feedback and/or manipulating perceptions of task difficulty requires consideration. ...
Youth athletes are ideal candidates for novel therapeutic motor learning interventions that leverage the plasticity of the central nervous system to promote desirable biomechanical adaptions. We summarize the empirical data supporting the three pillars of the Optimizing Performance Through Intrinsic Motivation and Attention for Learning (OPTIMAL) theory of motor learning and expand on potential neurophysiologic mechanisms that will support enhanced movement mechanics in youth to optimize prevention programs for reduced injury risk, injury rehabilitation, exercise performance, and play (Prevention Rehabilitation Exercise Play; PREP). Specifically, we highlight the role of motivational factors to promote the release of dopamine that could accelerate motor performance and learning adaptations. Further, we detail the potential for an external focus of attention to shift attentional allocation and increase brain activity in regions important for sensorimotor integration to facilitate primary motor cortex efficiency. This manuscript serves to provide the most current data in support of the application of OPTIMAL PREP training strategies of the future.
... Four studies using the Ebbinghaus illusion showed that projecting small circles around a circular target led to increased perceived target size and improved golf-putting performance and learning (e.g., Bahmani, Wulf, Ghadiri, Karimi, & Lewthwaite, 2017;Chauvel et al., 2015;Witt et al., 2012, Wood, Vine, & Wilson, 2013. Another study of skilled shooters found increased perceived target size and improved shooting performance (but not learning) when small circles were placed around the target (Bahmani, Diekfuss, Rostami, Ataee, & Ghadiri, 2018). In contrast to the abovementioned studies, Maquestiaux et al. (2020, Exp. 2 and Exp. 3) found that the Ebbinghaus illusion affected target size perception when both illusions were shown side by side but did not affect putting performance. ...
... Four studies used the Ebbinghaus illusion and measured selfefficacy, performance, and learning. One study found that small circles around a circular target led to increased self-efficacy and improved performance (Bahmani et al., 2018) and two studies reported increased self-efficacy and improved performance and learning (Bahmani et al., 2017;Chauvel et al., 2015). In contrast, only one study found no differences in self-confidence, but reported improved performance when the target was perceived as small due to the projection of larger circles around it (Cañal-Bruland et al., 2016). ...
This study examined how providing criteria for success of different levels of difficulty affected perceived expectations to succeed, performance, and learning in a golf-putting task. Twenty-nine physical education students were divided into three experimental groups: (a) a large-circle (LC) group that practiced 10 blocks of five putts, each with a 40 cm diameter circle around the target; (b) a small circle (SC) group that practiced with a 10 cm diameter circle around the target; and (c) a control (C) group that practiced with a 25 cm diameter circle around the target. Forty-eight hours after practice, the participants performed a retention test and a transfer test with a 25 cm diameter circle. The transfer test included putting from a greater distance and from a different angle. Throughout the study, we asked the participants to tell us what they think their chances are to land 1, 2, 3, 4, and 5 balls out of 5 possible balls in each block. There were four main findings: (a) the SC group had lower expectancies of success compared with the LC and C groups in acquisition; (b) there were no group differences in performance or learning among groups; (c) golf club kinematic parameters worsened in the transfer test; and (d) the LC group reduced their expectancies of success from the retention to the transfer test, but the expectancies of the SC and C groups remained the same. We conclude that changes in success criteria affect expectancies of success but do not affect actual putting performance or learning.
... We adopted a common scoring system for aiming-related tasks studying motor performance and learning. (e.g., Bahmani, Diekfuss, Rostami, Ghadiri, & Ataee, 2018;Diekfuss, Ward, & Raisbeck, 2017;Raisbeck & Diekfuss, 2015Wulf, Chiviacowsky, & Cardozo, 2014;Wulf, Lewthwaite, Cardozo, & Chiviacowsky, 2018). Specifically, if the ball hit the bull's eye, 100 points were awarded, 90 points were given if the ball hit the first surrounding circle of the bulls-eye, 80 points were given for balls hitting third circle, and so forth (see Fig. 1). ...
We investigated whether children's motor imagery dominance modulated the relationship between attentional focus and motor learning of a tossing task. One hundred and thirty-eight boys (age: M = 10.13, SD = 0.65) completed the Movement Imagery Questionnaire – Children (MIQ-C) to determine imagery modality dominance (kinesthetic, internal-visual, external-visual) and were randomly assigned to either an internal (n = 71) or external (n = 67) attentional focus group. Participants completed 60 trials of a tossing task with their non-dominant hand on day 1. Participants in the internal focus group were asked “to focus on the throwing arm”, whereas participants in the external focus group were instructed “to focus on the ball.” A retention test was conducted 24 h later to assess motor learning. Overall, the results from a nested, multiple linear regression analysis indicated the degree to which internal or external focus influences children's throwing accuracy is dependent upon their motor imagery modality dominance. Specifically, higher levels of external-visual imagery dominance resulted in greater motor learning for children adopting an external focus. In contrast, higher values of kinesthetic imagery dominance resulted in reduced motor learning for children who adopted an external focus. Despite the need for future research, we recommend motor imagery modality dominance assessments be considered when investigating the influence of attentional focus on motor learning, particularly when the target population is children.
... ACL injury can also lead to fear of (re)injury-the most commonly cited reason among athletes who do not return to play [76]-potentially leading to increased muscular tension, fatigue, decreased coordination, and as a result, higher vulnerability to future injury [3]. As these psychological factors regarding perceived ability are critical for an athlete's successful return to sport [66,86], it is noteworthy that enhancing expectancies can improve self-efficacy [7,8] and could potentially reduce fear of (re)injury. ...
... For instance, during a single leg hop a clinician could safely place a cone at a distance perceived as "easy" to reach by the patient to enhance self-efficacy before increasing the perceived distance the patient strives to jump to. As an illustrative example with respect to youth play, instructors could even adopt the "Ebbinghaus Illusion" that can enhance self-efficacy and motor behavior by making targets appear larger than they actually are [7,8,19,82]. For instance, this principle could be used in youth by creating "perceptually larger targets" an athlete must kick a soccer ball towards; small objects could surround a goal target to make it appear larger. ...
Youth may be particularly responsive to motor learning training strategies that support injury-resistant movement mechanics in youth for prevention programs that reduce injury risk, injury rehabilitation, exercise performance, and play more generally (Optimizing Performance Through Intrinsic Motivation and Attention for Learning Prevention Rehabilitation Exercise Play; OPTIMAL PREP) One purpose of the present manuscript was to provide clinical applications and tangible examples of how to implement the proposed techniques derived from OPTIMAL theory into PREP strategies for youth. A secondary purpose was to review recent advances in technology that support the clinical application of OPTIMAL PREP strategies without extensive resources/programming knowledge to promote evidence-driven tools that will support practitioner feedback delivery. The majority of examples provided are within the context of anterior cruciate ligament (ACL) injury rehabilitation, but we emphasize the potential for OPTIMAL PREP strategies to be applied to a range of populations and training scenarios that will promote injury resistance and keep youth active and healthy.
... Memory-guided movements require the performance to hold target-related information in working memory while maintaining fixation on another object (e.g. target and golf ball) (Bahmani, Diekfuss, Rostami, Ataee, & Ghadiri, 2018). We also aimed to show the relationship between planning and control based on Glover and Dixon's model in children with ASD. ...
It is still unknown whether visual illusion can bias motor performance in Autism Spectrum Disorders (ASD) individuals. The present study aimed to evaluate the effect of visual illusion on performance in children with ASD in a far-aiming skill. In a within-subject design, participants (n = 20, IQ > 70, mean age: 10.15) performed golf putting task in the control and visual illusion condition. The quiet eye duration (QED) was measured as an objective measure of planning in golf putting performance. The QED was recorded by the eye-tracking headset. Results showed visual illusion biased golf putting performance in ASD children, but it did not affect QED in children with ASD. The findings suggest that the effect of visual illusion would bias performance in children with ASD. The results are consistent with Glover and Dixon's model. Usage of visual illusion in far-aiming skills can improve accuracy in children with ASD. ARTICLE HISTORY
