Effects of Real-Time Feedback Methods on Static Balance Training in Stroke Patients: A Randomized Controlled Trial.

BACKGROUND: The purpose of this study was to investigate the effects of real-time feedback methods on static balance training in stroke patients. There are two types of real-time feedback methods, as follows: one is Knowledge of Result (KR), and the other is Knowledge of Performance (KP). METHOD: Thirty stroke patients participated in this study and were randomly assigned to the KR group (n = 15) or the KP group (n = 15). All of the groups underwent real-time feedback training for four weeks (30 min per session, five sessions per week). The primary outcomes were sway length, sway velocity, and area 95%, which were assessed before and after the intervention. The secondary outcomes included the Berg Balance Scale, the Fugl Meyer Assessment for Lower Extremity, the Postural Assessment Scale for Stroke Trunk Impairment Scale, and the Fall Efficacy Scale. A group × time interaction was assessed using two-way ANOVA with repeated measures. RESULT: There was a significant increase over time in all outcomes (p < 0.05). Significant differences were observed for a group × time interaction in sway length and area 95% (p < 0.05). CONCLUSIONS: Real-time feedback training for static balance enhanced stroke patients' static balance abilities, clinical outcome assessments, and promoted self-efficacy against falls.

Location-based electrotactile feedback localizes hitting point in virtual-reality table tennis game.

Learning new motor skills is often challenged by sensory mismatches. For reliable sensory information, people have actively employed sensory intervention methods. Visual assistance is the most popular method to provide sensory information, which is equivalent to the knowledge of performance (KP) in motor tasks. However, its efficacy is questionable because of visual-proprioceptive mismatch as well as heavy intrinsic visual and cognitive engagement in motor tasks. Electrotactile intervention is a promising technique to address the current limitations, as it provides KP using tactile feedback that has a close neurophysiological association with proprioception. To test its efficacy, we compared the effects of visual and electrotactile assistance on hitting point localization of the table-tennis racket during virtual-reality table-tennis game. Experimental results suggest that location-based electrotactile feedback outperforms visual assistance in localizing the hitting point on a table-tennis racket during virtual-reality table-tennis game. Our study showed the potential of electrotactile intervention for improving the efficacy of new motor skill training.

Effectiveness of different extrinsic feedback forms on motor learning in children with cerebral palsy: a systematic review.

PURPOSE: Motor learning interventions for children with cerebral palsy (CP) that elicit relatively permanent and transferable improvements in motor skill capability are essential. Knowledge is needed about the augmented feedback forms that most effectively promote this. This review aims to collect and analyze the current evidence for the effectiveness of different forms of feedback for motor learning in children with CP to improve motor task performance. METHODS: PubMed, PsycInfo, and Cochrane Library were searched to identify relevant studies. Studies were included if (1) they were conducted in children with CP or compared children with CP to TD children and (2) a form of augmented feedback related to a motor task was administered. RESULTS: Initially, 401 records were identified for screening. Ultimately, 12 articles were included in the review. The evidence thus far supports the expectancy that children with CP generally benefit from feedback provided during or after performing a movement task. CONCLUSION: Due to the heterogeneity of existing studies, it is difficult to draw firm conclusions regarding relative effectiveness of feedback forms. This review showed that more high-quality research is warranted on the effectiveness of specific feedback forms on motor learning in children with CP.Implications for RehabilitationChildren with CP benefit from several forms of knowledge of performance or knowledge of results feedback provided during or after performing a movement task.Feedback should not be provided with every performed trial.Feedback frequency can best be reduced by letting children determine after which trials they want feedback.Learning curves under similar feedback conditions varied largely between children, warranting tailor-made forms of feedback to be applied during motor learning and rehabilitation.

Beyond animated skeletons: How can biomechanical feedback be used to enhance sports performance?

Biomechanical feedback technologies are becoming increasingly prevalent in elite athletic training environments but how the kinematic and kinetic data they produce can be best used to improve sports techniques and enhance sports performance is unclear. This paper draws on theoretical and empirical developments in the motor control, skill acquisition, and sports biomechanics literatures to offer practical guidance and strategic direction on this issue. It is argued that the information produced by biomechanical feedback technologies can only describe, with varying degrees of accuracy, what patterns of coordination and control are being adopted by the athlete but, crucially, it cannot prescribe how these patterns of coordination and control should be modified to enhance sports performance. As conventional statistical and theoretical modelling paradigms in applied sports biomechanics provide limited information about patterns of coordination and control, and do not permit the identification of athlete-specific optimum sports techniques, objective criteria on which to base technical modifications that will consistently lead to enhanced performance outcomes cannot reliably be established for individual athletes. Given these limitations, an alternative approach, which is harmonious with the tenets of dynamical systems theory and aligned with the pioneering insights of Bernstein (1967) on skill acquisition, is advocated. This approach involves using kinematic and kinetic data to channel the athlete's search towards their own unique 'optimum' pattern of coordination and control as they actively explore their perceptual-motor workspace during practice. This approach appears to be the most efficacious use of kinematic and kinetic data given current biomechanical knowledge about sports techniques and the apparent inability of existing biomechanical modelling approaches to accurately predict how technique changes will impact on performance outcomes for individual athletes.

Efectividad del feedback aumentado en el desempeño de destrezas motrices: un meta-análisis / Effectiveness of Augmented Feedback on Motor Skills Performance: A Meta-Analysis

Resumen El propósito del presente estudio fue examinar la efectividad del feedback aumentado (FA) en el desempeño y aprendizaje de destrezas motrices. La búsqueda de los estudios se realizó en bases de datos digitales, revisando referencias y consultando a personal experto del área. La selección de los estudios y la extracción de los datos fue realizada por las tres autoras de forma independiente. La calidad de los estudios se evaluó utilizando una modificación de la escala TESTEX. Con el modelo de efectos aleatorios se calculó el tamaño de efecto (TE) de la diferencia de medias estandarizada. Se examinó la heterogeneidad con la Q estadística y la consistencia con I 2 . Veinte estudios cumplieron los criterios de inclusión. Un total de 95 TE fueron calculados, lo cual representa a 949 participantes. El uso de FA durante la práctica física aumentó el desempeño significativamente entre el pretest y la adquisición (TE = 0.87; IC95% = 0.65, 1.10; n = 47; Q = 183.6, I 2 = 74.41%; p < 0.01); mientras que el desempeño disminuyó significativamente entre la prueba de adquisición y la retención, después de que el FA fue suspendido (TE = -0.74, IC95% = -1.04, -0.44; n = 45; Q = 377.45, I 2 . = 88.34%; p < 0.01). Se analizaron la edad y el nivel de habilidad de los sujetos participantes, el tipo de destreza y las características de la práctica y el tipo de FA como posibles variables moderadoras. Los resultados sugieren que el desempeño mejora en la adquisición al recibir FA durante la práctica física, y disminuye en la retención, una vez que no está disponible; no obstante, el uso de FA promueve significativamente el aprendizaje de destrezas motrices.

Abstract The purpose of this study was to use the meta-analytic approach to assess the effectiveness of augmented feedback (AF) on performance and learning of motor skills. Studies were retrieved by searching electronic databases, cross refereeing, and expert criteria. Studies were selected and data was extracted by the three authors independently. The quality of the studies was measured by a modify TEXTEX scale. Random effects models using the standardized mean difference effect size (ES) were used to pool results. Risk of bias, heterogeneity, and inconsistency was examined. Twenty studies met the inclusion criteria. A total of 95 ESs were calculated, representing 949 participants. During physical practice, performance increases from pretest to acquisition when receiving AF (ES = 0.87; 95%CI = 0.65, 1.10; n = 47; I 2 . = 74.41; Q= 183,6; p < 0.01); while performance significantly decrease between the acquisition and retention phase after AF was removed (ES = -0.74; 95%CI = -1.04, -0.44; n = 45; I 2 . = 88.34; Q = 377.45; p < 0.01). Age and skill level ability of the participants, type of task, and practice characteristics, and type of feedback were analyzed as potentially moderator variables. Results suggest that AF increases performance in motor skills during physical practice, but performance decreases after removing AF in retention; all due, AF enhances learning of motor skills.

Resumo O objetivo do presente estudo foi examinar a eficácia do aumento do feedback (AF) sobre o desempenho e a aprendizagem das habilidades motoras. Foram pesquisados estudos em bancos de dados digitais, verificando referências e consultando especialistas na área. A seleção do estudo e a extração de dados foi feita pelos três autores independentemente. A qualidade dos estudos foi avaliada utilizando uma modificação da escala TESTEX. Sob o modelo de efeitos aleatórios, foi calculado o tamanho do efeito (TE) da diferença média padronizada. A heterogeneidade foi examinada usando o Q estatístico e a consistência usando o I2. Vinte estudos preencheram os critérios de inclusão. Um total de 95 TE's foi calculado, representando 949 participantes. O uso de AF durante a prática física aumentou significativamente o desempenho entre o pré-teste e a aquisição (ET = 0,87; CI95% = 0,65, 1,10; n = 47; Q = 183,6, I2 = 74,41%; p < 0. 01); enquanto o desempenho diminuiu significativamente entre o teste de aquisição e a retenção, depois que o AF foi suspenso (SD = -0,74, 95% CI = -1,04, -0,44; n = 45; Q = 377,45, I2. = 88,34%; p < 0,01). A idade e o nível de habilidade dos participantes, tipo de habilidade e características de prática, e tipo de AF foram analisados como possíveis variáveis moderadoras. Os resultados sugerem que o desempenho melhora na aquisição ao receber AF durante a prática física, e diminui na retenção, uma vez que ela não está disponível; entretanto, o uso de AF promove significativamente o aprendizado das habilidades motoras.

Quantifying bi-variate coordination variability during longitudinal motor learning of a complex skill.

Biofeedback (BFb) can enhance the motor learning process by guiding skill exploration. Too much BFb, however, can foster dependency leading to skill retention deficits once removed. A reducing BFb schedule could negate dependency effects, however limited methodologies exist to assess the effectiveness of an intervention during application. This research proposes a new bi-variate method (CI2Area) to quantify coordination variability (CoordVar) as a measure of skill exploration during a motor learning intervention. Thirty-two participants were introduced to a novel explosive-lunge task. A BFb group (n = 16) were provided with visual BFb on rear hip, knee and ankle joint extension magnitudes and timing during a 26-week reducing schedule BFb intervention. CoordVar of hip-knee and knee-ankle angular velocities were quantified by calculating the area encompassed by the 95% confidence intervals of joint coupling angular-velocity bi-variate plots (CI2Area). Linear regressions were fitted to group and individual CoordVar longitudinal data. The BFb was effective in successfully altering whole limb technique within just two sessions, and these changes were retained. The BFb group demonstrated a continual increase of CoordVar throughout the intervention, showing continual skill exploration strategies, while the Control group remained unchanged. Gradually increasing time between sessions, using a longitudinally reducing BFb schedule, successfully negates dependency effects on BFb while also encouraging motor learning. Manipulating time between sessions allows for the provision of a high frequency of 100% BFb without fostering dependency. The CI2Area method was able to detect individual exploration strategies and could be used in the future to direct individual intervention modifications.

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 (ps < .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.

Rewarding feedback promotes motor skill consolidation via striatal activity.

Knowledge of performance can activate the striatum, a key region of the reward system and highly relevant for motivated behavior. Using functional magnetic resonance imaging, striatal activity linked to knowledge of performance was measured during the training of a repetitive arc-tracking task. Knowledge of performance was given after a random selection of trials or after good performance. The third group received knowledge of performance after good performance plus a monetary reward. Skill learning was measured from pre- to post- (acquisition) and from post- to 24h posttraining (consolidation). Our results demonstrate an influence of feedback on motor skill learning. Adding a monetary reward after good performance leads to better consolidation and higher ventral striatal activation than knowledge of performance alone. In turn, rewarding strategies that increase ventral striatal response during training of a motor skill may be utilized to improve skill consolidation.

Effectiveness of knowledge of result and knowledge of performance in the learning of a skilled motor activity by healthy young adults.

[Purpose] The acquisition of motor skills are fundamental to human life. There is a lack of research on whether knowledge of performance or knowledge of result as augmented feedback is more effective. The objective of this study was to compare the effectiveness of knowledge of result and knowledge of performance in the learning of a skilled motor activity by healthy young adults. [Subjects and Methods] A total of thirty healthy young adult males and females without any neurological or musculoskeletal impairment, between the age of 18-30 years were the subjects of the study. They were randomly allocated to 2 groups: group 1 was given knowledge of result as feedback, and knowledge of performance was given as feedback to group 2. Both the groups practiced the task of throwing a soft spongy ball for 6 days per week for 4 weeks, with 40 trials each day. The outcome measure used was the distance of the throw. [Results] The results were analyzed using the t-test. The mean distances thrown by both the groups showed highly significant improvements and throwing distance of group 2 showed better improvement than that of group 1. [Conclusion] Both types of augmented feedback were effective at improving skilled motor activity, but the knowledge of performance group showed better improvement than the knowledge of result group.

The use of augmented auditory feedback to improve arm reaching in stroke: a case series.

PURPOSE: After practice, augmented feedback is the most important factor that facilitates motor learning. We assess the potential effectiveness of two types of augmented auditory feedback on the re-learning of arm reaching in individuals with stroke: (a) real-time knowledge of performance (KP) feedback and (b) rhythmic cueing in the form of knowledge of results (KR) feedback. METHOD: Five participants with stroke underwent short-term practice, reaching with their affected arm with KP, KR and no feedback, on separate days. We assessed range of motion of the upper extremity (shoulder, elbow) and trunk, mean error and variability of the performed trajectory, and movement time, before and after training. RESULTS: All participants benefitted from practice with feedback, though the effects varied across participants and feedback type. In three participants, KP feedback increased elbow extension and reduced compensatory trunk flexion. In four participants, KR feedback reduced movement time taken to perform the reach. Of note, one participant benefitted mostly from KP feedback, which increased shoulder flexion and elbow extension, and decreased compensatory trunk flexion and mean error. CONCLUSIONS: Within day practice with augmented auditory feedback improves reaching in individuals with stroke. This warrants further investigation with longer practice periods in a larger sample size. IMPLICATIONS FOR REHABILITATION: After practice, augmented feedback is the second most important factor that facilitates motor learning. Music-based augmented auditory feedback has potential to enhance reaching abilities in individuals with stroke. Future studies are warranted to evaluate the long-term effectiveness of this feedback over a longer training period in a larger sample size.

Self-controlled learning benefits: exploring contributions of self-efficacy and intrinsic motivation via path analysis.

Research has shown learning advantages for self-controlled practice contexts relative to yoked (i.e., experimenter-imposed) contexts; yet, explanations for this phenomenon remain relatively untested. We examined, via path analysis, whether self-efficacy and intrinsic motivation are important constructs for explaining self-controlled learning benefits. The path model was created using theory-based and empirically supported relationships to examine causal links between these psychological constructs and physical performance. We hypothesised that self-efficacy and intrinsic motivation would have greater predictive power for learning under self-controlled compared to yoked conditions. Participants learned double-mini trampoline progressions, and measures of physical performance, self-efficacy and intrinsic motivation were collected over two practice days and a delayed retention day. The self-controlled group (M = 2.04, SD = .98) completed significantly more skill progressions in retention than their yoked counterparts (M = 1.3, SD = .65). The path model displayed adequate fit, and similar significant path coefficients were found for both groups wherein each variable was predominantly predicted by its preceding time point (e.g., self-efficacy time 1 predicts self-efficacy time 2). Interestingly, the model was not moderated by group; thus, failing to support the hypothesis that self-efficacy and intrinsic motivation have greater predictive power for learning under self-controlled relative to yoked conditions.

Depressive symptoms influence use of feedback for motor learning and recovery in chronic stroke.

PURPOSE: Sensorimotor impairments and depressive symptoms (PSD) influence arm motor recovery post-stroke. Feedback provision improves upper limb motor learning in patients with chronic stroke but factors including PSD may affect ability to use feedback. We evaluated the influence of PSD on the ability to use auditory feedback for upper limb recovery and motor learning in patients with chronic stroke. METHODS: Participants (n = 24) practiced 72 pointing movements/session (6 targets, 12 sessions, randomized) with auditory feedback on movement speed and trunk displacement. The presence of PSD (Beck's Depression Inventory; BDI-II) was assessed at pre-intervention (PRE). Arm motor impairment (Fugl-Meyer Assessment, shoulder horizontal adduction, shoulder flexion, elbow extension ranges, trunk displacement) and arm use (Motor Activity Log) were assessed at PRE, immediately after (POST) and retention (3 mos; RET). Participants were divided into two groups based on BDI-II scores: ≥ 14/63 (DEP group; n = 8; score: 20.5 ± 7.5) and ≤ 13/63 (no PSD (ND) group; n = 16; score: 5.0 ± 3.8). Changes in impairment and arm use levels were assessed (mixed-model ANOVAs). RESULTS: All participants improved arm use. DEP had lower Fugl-Meyer scores, used more compensatory trunk displacement and had lower shoulder horizontal adduction range compared to ND. CONCLUSION: The presence of PSD diminished the ability to use auditory feedback for arm motor recovery and motor learning.

Conhecimento de performance com base no Teste do Desempenho Motor do Nado Crawl, na aprendizagem do nado crawl / Knowledge of performance based on the swimming crawl motor performance test in the learning of swimming crawl / Conocimiento de la performance en base a la prueba de rendimiento motor natación estilo crawl, luego de buenos contra malos intentos de práctica, en el aprendizaje del estilo crawl

ResumoO objetivo deste estudo foi verificar os efeitos do conhecimento de performance (CP), com base no teste do desempenho motor do nado crawl (TDMND) (Corazza et al., 2006), na aprendizagem do nado crawl. Participaram do estudo 41 adultos. Enquanto um grupo recebeu CP após boas tentativas, o outro recebeu CP após as más tentativas. O TDMNC, composto por 29 itens, foi usado para a elaboração das informações de CP, assim como para a constatação dos níveis de aprendizagem. Para ambos os grupos, independentemente do CP fornecido, foi detectada diferença entre o pré e o pós-teste, o que indica sucesso no processo de aprendizagem. No entanto, na comparação entre os pós-testes, não foram observadas diferenças significativas entre os grupos. A complexidade do teste e a dificuldade dos aprendizes em discriminar entre boas e más tentativas de prática são discutidos.

AbstractThe objective of this study was to verify the effects of knowledge of performance (KP) based on the Swimming Crawl Motor Performance Test (SCMPT) (Corazza et al., 2006) on the learning of swimming crawl. Forty-one undergraduate students, divided into two groups, participated in the study. While one group received KP after good trials, the other received KP after poor trials. The SCMPT, consisting of 29 items, was used for KP elaboration, as well as for motor learning assessment. Difference between groups was not observed on the post-test. The complexity of the test and the difficulty of learners in discriminating between good and bad trials are discussed.

ResumenEl objetivo de este estudio fue evaluar los efectos del conocimiento de la performance (CP) en base a la Prueba de Rendimiento Motor del Estilo Crawl (Corazza et al., 2006), en el aprendizaje del nado crawl. Participaron del estudio 41 adultos, divididos en dos grupos: G-buenos que recibieron un CP luego de buenos intentos de práctica y G-malos que recibieron CP luego de malas tentativas de práctica. La prueba, que consta de 29 artículos, se utilizó para la preparación de la información para CP, así como para la evaluación de los niveles de aprendizaje. Para ambos grupos, independientemente del CP realizado, fue detectada una diferencia entre el pre y el pos test, indicando una mejora en el proceso de aprendizaje. No se encontró diferencia entre los grupos pos test. La complejidad de la prueba y la dificultad de los alumnos a discriminar entre los buenos y malos intentos de práctica se discuten.

Knowledge of errors in the teaching-learning process of judo-techniques: osoto-guruma as a case study.

The aim of this article was to suggest some changes in the teaching-learning process methodology of the judo osoto-guruma technique, establishing the action sequences and the most frequent technical errors committed when performing them. The study was carried out with the participation of 45 students with no experience regarding the fundamentals of judo (21 men and 24 women; age=24.02±3.98 years old) from the Bachelor of Science of Physical Activity and Sport Science at the University of Vigo. The proceeding consisted of a systematic observation of a video recording registered during the technique execution. Data obtained were analyzed by means of descriptive statistics and sequential analysis of T-Patterns (obtained with THEME v.5. Software), identifying: a) the presence of typical inaccuracies during the technique performance; b) a number of chained errors affecting body balance, the position of the supporting foot, the blocking action and the final action of the arms. Findings allowed to suggest some motor tasks to correct the identified inaccuracies, the proper sequential actions to make the execution more effective and some recommendations for the use of feedback. Moreover, these findings could be useful for other professionals in order to correct the key technical errors and prevent diverse injuries.

Frequency of provision of knowledge of performance on skill acquisition in older persons.

The provision of feedback is a crucial factor for the evolution of the learner's performance. It is known that the knowledge of performance has the function of guiding the learner's attention to critical aspects of the movement pattern. The objective of this study was to examine the effect of frequency of knowledge of performance (KP) during the acquisition of the basketball free throw in older persons. Sixty active individuals (men and women) aged 60-69 years of age, divided into three experimental groups received KP in 100, 66, and 33% of their attempts during three practice sessions totaling 90 trials. The task was the basketball free throw. Volunteers were asked to conduct tests of immediate retention, 24 h retention, and 24 h transfer test, after the last practice session. During the acquisition phase, the volunteers received KP on the movement pattern on the previous attempt, which was obtained from a qualitative hierarchical checklist of the free throw (14 items). Sessions were recorded in order to confirm whether volunteers were able to score throughout sessions. ANOVA indicated that all individuals showed an improved performance in the retention and transfer tests. But the KP frequency of 66% was superior in both qualitative (movement pattern) and quantitative (score) measurements throughout the trials (p ≤ 0.05). In conclusion older persons seem to need an optimal KP frequency supply during the learning process.

Benefits of bandwidth feedback in learning a complex gymnastic skill.

The aim of this study was to examine the effects of two different frequencies of feedback during the process of learning a complex gymnastic skill, the round-off salto backward tucked. Thirty male acrobats participated in the study. They were randomly assigned to two groups: B - bandwidth feedback (n=15) or C - 100% feedback (n=15). Group B was provided with error information regarding the key elements of movement techniques only (bandwidth feedback). Our research demonstrates the advantage of augmented feedback information related to errors in the key elements. Information about errors in the key elements during learning a complex gymnastic skill prevents the gymnast from becoming overwhelmed, which promotes better motor control. These results provide support for the generalisation of bandwidth feedback principles to a complex task. Our research shows that the guidance hypothesis can also be tested in practical settings for a complex movement task.

The effects of self-controlled video feedback on the learning of the basketball set shot.

Allowing learners to control some aspect of instructional support (e.g., augmented feedback) appears to facilitate motor skill acquisition. No studies, however, have examined self-controlled (SC) video feedback without the provision of additional attentional cueing. The purpose of this study was to extend previous SC research using video feedback about movement form for the basketball set shot without explicitly directing attention to specific aspects of the movement. The SC group requested video feedback of their performance following any trial during the acquisition phase. The yoked group received feedback according to a schedule created by a SC counterpart. During acquisition participants were also allowed to view written instructional cues at any time. Results revealed that the SC group had significantly higher form scores during the transfer phase and utilized the instructional cues more frequently during acquisition. Post-training questionnaire responses indicated no preference for requesting or receiving feedback following good trials as reported by Chiviacowsky and Wulf (2002, 2005). The nature of the task was such that participants could have assigned both positive and negative evaluations to different aspects of the movement during the same trial. Thus, the lack of preferences along with the similarity in scores for feedback and no-feedback trials may simply have reflected this complexity. Importantly, however, the results indicated that SC video feedback conferred a learning benefit without the provision of explicit additional attentional cueing.

Efeitos de faixas de amplitude de CP na aprendizagem do saque tipo tênis do voleibol / Effects of the bandwidth KP on the learning of the volleyball tennis serve

Este estudo teve como objetivo investigar os efeitos de duas faixas de amplitude de Conhecimento de Performance (CP) na aprendizagem do saque tipo tênis do voleibol. Essa questão foi testada com uma faixa de amplitude estreita e uma ampla e mais um grupo controle. O estudo foi composto por um pré-teste, fase de aquisição e teste de retenção. Foram analisadas medidas de desempenho e dos componentes do padrão da habilidade. Apesar dos grupos mostrarem desempenho semelhante no teste de retenção, a faixa ampla foi a única que levou a melhora do desempenho. Além disso, a faixa ampla conduziu a mais mudanças no padrão da habilidade do que a faixa estreita ou o grupo controle.

This study aimed to investigate two bandwidth Knowledge of Performance (KP) effects on the learning of the volleyball tennis serve. This question was tested with a thin and wide bandwidth KP plus a control group. The study was composed by a pre test, acquisition phase and retention test. It was analyzed performance and components of the motor pattern measures. Although the groups showed similar performance on retention test, only wide bandwidth conducted to a better performance. Although all groups showed similar performance during retention test only the wide bandwidth conducted to performance improvement. Moreover, the wide bandwidth conducted to more changes in movement pattern than thin bandwidth or control group.

Frequent external-focus feedback enhances motor learning.

The present study examined the hypothesis that feedback inducing an external focus of attention enhances motor learning if it is provided frequently (i.e., 100%) rather than less frequently. Children (10- to 12-year-olds) practiced a soccer throw-in task and were provided feedback about movement form. The feedback statements, provided either after every (100%) or every third (33%) practice trial, were similar in content but induced either an internal focus (body-movement related) or external focus (movement-effect related). The results demonstrated that learning of the movement form was enhanced by external-focus feedback after every trial (100%) relative to external-focus feedback after every third trial (33%) or internal-focus feedback (100%, 33%), as demonstrated by immediate and delayed transfer tests without feedback. There was no difference between the two internal-focus feedback groups. These findings indicate that the attentional focus induced by feedback is an important factor in determining the effectiveness of different feedback frequencies. We argue that the informational properties of feedback cannot sufficiently account for these and related findings, and suggest that the attentional role of feedback be given greater consideration in future studies.

A Comparison of Two References for Using Knowledge of Performance in Learning a Motor Task.

In the present study, the learning of a task in which the goal of the movement was not isomorphic with a specific movement pattern was examined. The subjects' (N = 48) goal in the task was to be both spatially and temporally accurate in reaching 4 targets with a right arm lever movement. After each acquisition trial, the displacement profile of the movement just produced was provided to all subjects as knowledge of performance (KP). The relative effectiveness of 2 possible references, with which subjects could compare the KP, was examined. One of the references examined was knowledge of results (KR), which was provided by reporting the total absolute timing and amplitude errors from the 4 targets. The other reference examined was a criterion template (CT), Which was defined as the most efficient movement pattern for reaching the 4 targets. In the feedback display, CT was superimposed on the displacement profile of the movement just produced. A factorial design, in which 2 levels of KR (KR, no KR) were crossed with 2 levels of CT (CT, no CT), produced 4 feedback conditions. After 120 acquisition trials with feedback, immediate and delayed retention tests without feedback and a reacquisition test with KR (20 trials per test) were conducted. Acquisition results indicated that KR was a better reference than CT for performing the timing aspect of the movement and for producing the generalized motor program (GMP) associated with the most efficient movement pattern. Delayed retention results showed that KR was also a better reference than CT for learning the most efficient GMP. The calibration strategy undertaken by subjects who were provided with KR during acquisition explains the superiority of the KR reference. The calibration strategy is compared with the pattern-matching activity that was probably undertaken by subjects who had received CT as a reference.