Social-comparative feedback affects motor skill learning

This study examined motivational effects of feedback on motor learning. Specifically, we investigated the influence of social-comparative feedback on the learning of a balance task (stabilometer). In addition to veridical feedback (error scores reflecting deviation from the target horizontal platform position) about their own performance after each trial, two groups received false normative information about the “average” score of others on that trial. Average performance scores indicated that the participant's performance was either above (better group) or below (worse group) the average, respectively. A control group received veridical feedback about trial performance without normative feedback. Learning as a function of social-comparative feedback was determined in a retention test without feedback, performed on a third day following two days of practice. Normative feedback affected the learning of the balance task: The better group demonstrated more effective balance performance than both the worse and control groups on the retention test. Furthermore, high-frequency/low-amplitude balance adjustments, indicative of more automatic control of movement, were greater in the better than in the worse group. The control group exhibited more limited learning and less automaticity than both the better and the worse groups. The findings indicate that positive normative feedback had a facilitatory effect on motor learning.     

Augmented visual, auditory, haptic, and multimodal feedback in motor learning: A review

It is generally accepted that augmented feedback, provided by a human expert or a technical display, effectively enhances motor learning. However, discussion of the way to most effectively provide augmented feedback has been controversial. Related studies have focused primarily on simple or artificial tasks enhanced by visual feedback. Recently, technical advances have made it possible also to investigate more complex, realistic motor tasks and to implement not only visual, but also auditory, haptic, or multimodal augmented feedback. The aim of this review is to address the potential of augmented unimodal and multimodal feedback in the framework of motor learning theories. The review addresses the reasons for the different impacts of feedback strategies within or between the visual, auditory, and haptic modalities and the challenges that need to be overcome to provide appropriate feedback in these modalities, either in isolation or in combination. Accordingly, the design criteria for successful visual, auditory, haptic, and multimodal feedback are elaborated.     

Positive social-comparative feedback enhances motor learning in children

ObjectivesThe present study investigated the influence of social-comparative feedback on the learning of a throwing task in 10-year-old children.DesignTwo-group experimental design, including a practice phase and retention test.MethodBoth groups of participants, a positive social-comparative feedback and a control group, received veridical feedback about their performance (accuracy score) after each practice trial. In addition, after each block of 10 trials, the positive feedback group was given bogus feedback suggesting that their own performance was better than that of a peer group's on that block. One day after the practice phase, a retention test without (veridical or social-comparative) feedback was performed to assess learning effects as a function of feedback.ResultsThe positive feedback group demonstrated greater throwing accuracy than the control group on the retention test. In addition, questionnaire results indicated that this group scored higher in terms of perceived competence than the control group.ConclusionsThese findings demonstrate that feedback can have an important motivational function that affects the learning of motor skills in children.     

Effects of delayed visual feedback on motor control performance

The effects of delay of visual feedback on two kinds of sensorimotor tasks were investigated. On the reciprocal tapping task, accuracy of performance decreased for 200, 500, and 767 msec. delay. The number of errors for the 1000-msec. delay is smaller than those for the other three conditions of delay. On the hand-writing task of both Kanji letters and English words, performance showed a large decrement with increasing delay. The most frequent kinds of error were the type of insertion of line elements or letter duplication. It was interesting that the size of written letters increased with lengthening delays of visual feedback.     

Sensory feedback in the learning of a novel motor task

The role of different forms of feedback is examined in learning a novel motor task. Five groups of ten subjects had to learn the voluntary control of the abduction of the big toe, each under a different feedback condition (proprioceptive feedback, visual feedback, EMG feedback, tactile feedback, force feedback). The task was selected for two reasons. First, in most motor learning studies subjects have to perform simple movements which present hardly any learning problem. Second, studying the learning of a new movement an provide useful information for neuromuscular reeducation, where patients often also have to learn movements for which no control strategy exists. The results show that artificial sensory feedback (EMG feedback, force feedback) is more powerful than "natural" (proprioceptive, visual, and tactile) feedback. The implications of these results for neuromuscular reeducation are discussed.     

Neural mechanism underlying self-controlled feedback on motor skill learning

The present study investigated the neural mechanisms of self-controlled (SC) feedback underlying its learning advantages. Forty-two participants, including 24 females (16.43 ± 2.61 years) and 18 males (17.56 ± 0.86 years), were randomly assigned to a SC or yoked (YK) group. The 6-key-pressing task with a goal movement time was adopted as the experimental task. The behavioral results showed that the SC group demonstrated superior performance in transfer; however, the differences in retention did not reach statistical significance. Event-related potential analyses revealed that the SC group exhibited larger post-stimulus and post-feedback P3 amplitudes than the YK group in the frontal regions; these amplitudes were larger in the YK group in the parietal regions. The post-response error positivity amplitude was found to be larger in the YK group than in the SC group. These results suggest that SC feedback may allow the learner to more actively process the task stimuli and feedback information, and contributes to enhancing the learner’s motivation and attachment to the task being practiced. The present study provides a neurophysiological explanation for why SC feedback is effective in learning a new motor skill.     

Delayed sensory feedback in the learning of a novel motor task

Summary Generally the therapeutical effect of EMG feedback is viewed in terms of the immediate contiguity between response and information. According to this view any feedback delay would deteriorate the result. In this article the validity of this notion has been investigated. Three groups of normal subjects were required to perform a difficult movement under three feedback conditions: immediate EMG feedback, delayed EMG feedback, and a control (no EMG feedback) condition. The results indicated a significant difference between the EMG feedback groups and the control condition. However, no such difference was found between the immediate and delayed feedback conditions. The results suggested that the immediacy of the feedback is not the main factor in EMG feedback, but the specificity of the information.This study was supported by Grant no. 15-35-03 from the Netherlands Organization for the Advancement of Pure Research     

Marginally perceptible outcome feedback, motor learning and implicit processes

Participants struck 500 golf balls to a concealed target. Outcome feedback was presented at the subjective or objective threshold of awareness of each participant or at a supraliminal threshold. Participants who received fully perceptible (supraliminal) feedback learned to strike the ball onto the target, as did participants who received feedback that was only marginally perceptible (subjective threshold). Participants who received feedback that was not perceptible (objective threshold) showed no learning. Upon transfer to a condition in which the target was unconcealed, performance increased in both the subjective and the objective threshold condition, but decreased in the supraliminal condition. In all three conditions, participants reported minimal declarative knowledge of their movements, suggesting that deliberate hypothesis testing about how best to move in order to perform the motor task successfully was disrupted by the impoverished disposition of the visual outcome feedback. It was concluded that sub-optimally perceptible visual feedback evokes implicit processes.     

Methodology for motor learning: a paradigm for kinematic feedback

Knowledge of results (KR)--information feedback about goal achievement--has been one of the most extensively examined variables in motor learning. In most natural movement learning situations, however, instructors more common]y provide augmented information regarding various kinematic or kinetic aspects of the movement pattern itself (sometimes termed knowledge of performance, KP). But despite the inherent interest in kinematic feedback, several factors reviewed here have operated to inhibit its study, the most important of which has been the lack of a suitable laboratory task and paradigm. The limitations of earlier paradigms have concerned (a) the use of overly simple motor behaviors, probably to minimize the problems in kinematic measurement, (b) the tendency for the environmental goal or the task to be isomorphic with the kinematic pattern, and (c) thc failure to use transfer or retention tests as measures of learning effects of the feedback manipulations. In this article, we describe our efforts to create a new paradigm for kinematic feedback, the rationale for its development, and the details of its operation. Finally, we provide evidence that the task and paradigm are sensitive to manipulations of kinematic feedback, providing some assurance that the paradigm can potentially answer future research questions about the role of kinematic feedback for learning.     

Self-control over combined video feedback and modeling facilitates motor learning

Allowing learners to control the video presentation of knowledge of performance (KP) or an expert model during practice has been shown to facilitate motor learning (Aiken, Fairbrother, & Post, 2012; Wulf, Raupach, & Pfeiffer, 2005). Split-screen replay features now allow for the simultaneous presentation of these modes of instructional support. It is uncertain, however, if such a combination incorporated into a self-control protocol would yield similar benefits seen in earlier self-control studies. Therefore, the purpose of the present study was to examine the effects of self-controlled split-screen replay on the learning of a golf chip shot. Participants completed 60 practice trials, three administrations of the Intrinsic Motivation Inventory, and a questionnaire on day one. Retention and transfer tests and a final motivation inventory were completed on day two. Results revealed significantly higher form and accuracy scores for the self-control group during transfer. The self-control group also had significantly higher scores on the perceived competence subscale, reported requesting feedback mostly after perceived poor trials, and recalled a greater number of critical task features compared to the yoked group. The findings for the performance measures were consistent with previous self-control research.     

The effects of delayed and displaced visual feedback on motor control

Developments in television technology have made possible new approaches to the study of the role of visual feedback in motor control. In two experiments using a special videodisc recording and playback system, the effects of delaying for 66 msec a subject's view of his own hand during a target-directed movement was investigated. The observed effects of such visually delayed feedback compared to spatially distorted feedback produced by prisms led to three major conclusions: (a) despite the behavioral similarity (overshooting) induced by the two kinds of altered feedback, the role of each in the visual-motor control loop is different; (b) adaptation to and the after effect of the two kinds of altered feedback are based on different control mechanisms (c) the processing and use of visual information in hand control requires less time than previous experiments have indicated.     

Attention in learning

Learners exhibit many apparently irrational behaviors in their use of cues, sometimes learning to ignore relevant cues or to attend to irrelevant ones. A learning phenomenon called highlighting seems especially to demand explanation in terms of learned attention. Highlighting complements the classic phenomenon of conditioned blocking, which has been shown to involve learned inattention. Highlighting and blocking, along with a wide spectrum of other perplexing learning phenomena, can be accounted for by recent connectionist models in which both attentional shifting and associative learning are driven by the rational goal of rapid error reduction.     

Enhancing performance expectancies through visual illusions facilitates motor learning in children

In a recent study by Chauvel, Wulf, and Maquestiaux (2015), golf putting performance was found to be affected by the Ebbinghaus illusion. Specifically, adult participants demonstrated more effective learning when they practiced with a hole that was surrounded by small circles, making it look larger, than when the hole was surrounded by large circles, making it look smaller. The present study examined whether this learning advantage would generalize to children who are assumed to be less sensitive to the visual illusion. Two groups of 10-year olds practiced putting golf balls from a distance of 2 m, with perceived larger or smaller holes resulting from the visual illusion. Self-efficacy was increased in the group with the perceived larger hole. The latter group also demonstrated more accurate putting performance during practice. Importantly, learning (i.e., delayed retention performance without the illusion) was enhanced in the group that practiced with the perceived larger hole. The findings replicate previous results with adult learners and are in line with the notion that enhanced performance expectancies are key to optimal motor learning (Wulf & Lewthwaite, 2016).     

3D feedback and observation for motor learning: Application to the roundoff movement in gymnastics

In this paper, we assessed the efficacy of different types of visual information for improving the execution of the roundoff movement in gymnastics. Specifically, two types of 3D feedback were compared to a 3D visualization only displaying the movement of the expert (observation) as well as to a more ‘traditional’ video observation. The improvement in movement execution was measured using different methods, namely subjective evaluations performed by official judges, and more ’quantitative appraisals based on time series analyses. Video demonstration providing information about the expert and 3D feedback (i.e., using 3D representation of the movement in monoscopic vision) combining information about the movement of the expert and the movement of the learner were the two types of feedback giving rise to the best improvement of movement execution, as subjectively evaluated by judges. Much less conclusive results were obtained when assessing movement execution using quantification methods based on time series analysis. Correlation analyses showed that the subjective evaluation performed by the judges can hardly be predicted/ explained by the ‘more objective’ results of time series analyses.     

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.     

Leg-amplitude differentiation guided by haptic and visual feedback to detect alterations in motor flexibility due to Total Knee Replacement

Following total knee replacement (TKR), patients often persist in maladaptive motor behavior which they developed before surgery to cope with symptoms of osteoarthritis. An important challenge in physical therapy is to detect, recognize and change such undesired movement behavior. The goal of this study was to measure the differences in clinical status of patients pre-TKR and post-TKR and to investigate if differences in clinical status were accompanied by differences in the patients’' motor flexibility. Eleven TKR participants were measured twice: pre-TKR and post-TKR (twenty weeks after TKR). In order to infer maladaptation, the pre-TKR and post-TKR measurements of the patient group were separately compared to one measurement in a control group of fourteen healthy individuals. Clinical status was measured with the Visual Analogue Scale (VAS) for pain and knee stiffness and the Knee Injury and Osteoarthritis Outcome Score (KOOS). Furthermore, Lower-limb motor flexibility was assessed by means of a treadmill walking task and a leg-amplitude differentiation task (LAD-task) supported by haptic or visual feedback. Motor flexibility was measured by coordination variability (standard deviation (SD) of relative phase between the legs) and temporal variability (sample entropy) of both leg movements. In the TKR-group, the VAS-pain and VAS- stiffness and the subscales of the KOOS significantly decreased after TKR. In treadmill walking, lower-limb motor flexibility did not significantly change after TKR. Between-leg coordination variability was significantly lower post-TKR compared to controls. In the LAD-task, a significant decrease of between-leg coordination variability between pre-TKR and post-TKR was accompanied by a significant increase in temporal variability. Post-TKR-values of lower-limb flexibility approached the values of the control group. The results demonstrate that a clinically relevant change in clinical status, twenty weeks after TKR, is not accompanied by alterations in lower-limb motor flexibility during treadmill walking but is accompanied by changes in motor flexibility towards the level of healthy controls during a LAD-task with visual and haptic feedback. Challenging patients with non-preferred movements such as amplitude differentiation may be a promising tool in clinical assessment of motor flexibility following TKR.     

Control of children's observing responses by information feedback during visual discrimination learning

Four experiments examined the control of observing responses by information feedback during visual discrimination learning. Second-grade children participated in Experiment 1; kindergarten, second-, and fifth-grade children were subjects in Experiments 2 and 3, and grade 5 and adult subjects were tested in Experiment 4. In order to view the stimuli, subjects in Experiments 1, 2, and 3 activated lights in viewing boxes; in Experiment 4, stimulus fixations were measured using a corneal reflection technique. Fifth graders and adults observed the discriminative stimuli for longer times on trials following negative feedback than on trials following positive feedback; in contrast, kindergartener's observing was not affected by type of feedback. Second graders showed smaller and less reliable reactions to type of feedback than did older subjects. These results support the view that visual observing is controlled by cognitive processes associated with hypothesis testing.     

Adapting to target error without visual feedback

What information is necessary for the motor system to adapt its behaviour? Visual hand-to-target error provides salient information about reach performance, but can learning proceed without this information? We investigated adaptation to an unperceived target perturbation under visual open-loop conditions. Participants looked and reached, without any vision of their hand, to a target that jumped rightward at saccade onset (Perturbation condition) or remained stationary throughout the trial (Stationary condition). The target jump in the Perturbation condition was tied to the saccade, such that participants were unaware that it had occurred. Each type of exposure was followed by a posttest, in which participants reached to a target that disappeared at saccade onset. In the posttest, participants reached farther following exposure to the perturbation than they did following exposure to the stationary target, indicating that participants had learned from systematic exposure to the jump. These findings imply that online error induces motor learning, even when participants receive no visual information about their performance.