Go Tani

Learning benefits of self-controlled knowledge of results in 10-year-old children.

Self-controlled knowledge of results (KR) refers to a type of KR in which the learner actively chooses when to receive information about the outcome of his or her performance. That is, the learner is required to make a decision about whether or not he or she wants to receive KR after a trial. This approach differs from that used in most KR studies, in which the experimenter controls the frequency and schedule of KR delivery. Studies on self-efficacy perception (Bandura, 1977, 1993), strategies of self-regulated learning (Chen & Singer, 1992; Zimmerman & Ponz, 1986), and academic learning (Winne, 1995) have shown that learners’ ability to use cognitive or behavioral strategies in a self-controlled practice context enhances their performance and learning. In the motor learning area, Janelle and collaborators (Janelle, Kim, & Singer, 1995; Janelle, Barba, Frehlich, Tennant, & Cauraugh, 1997) were the first to adopt this approach by examining the effectiveness of self-controlled KR schedules. Using a novel throwing task, Janelle et al. (1997) allowed one group of learners to decide when to receive feedback about movement form. The self-control group showed clear learning advantages compared to those in the yoked group, in which each participant was yoked to one in the self-control group with regard to when KR was or was not provided. Although the feedback schedule was identical for both groups, providing learners the opportunity to decide when they wanted to receive feedback was more beneficial than externally controlled (yoked) feedback. The self-control group also showed superior learning compared to other groups with experimentercontrolled feedback schedules (e.g., summary KR). Learning benefits have also been found for other types of self-controlled practice, such as using assistive devices (i.e., ski poles) in learning a ski simulator task (Wulf, Clauss, Shea, & Whitacre, 2001; Wulf & Toole, 1999) and observational practice for learning basketball free-throw shooting (Wulf, Raupach, & Pfeiffer, 2005). The self-control benefits for learning appear to be a robust phenomenon. However, previous studies have exclusively used adults as participants. Thus, it is unclear whether the effects of this variable generalize to different motor development levels. An interesting question is whether children would also benefit from self-controlled practice. A potentially limiting factor in generalizing this effect to children lies in their information-processing capabilities. A number of studies suggested there are differences between children and adults in their capability to process information (e.g., Badan, Hauert, & Mounoud, 2000; Chi, 1977; Connolly, 1970, 1977; Lambert & Bard, 2005). According to Connolly (1970), changes in motor development during childhood can be attributed to two classes of variables. The first refers to “hardware” changes that occur as a function of growth. This includes such physical changes as increased strength and height as well as central nervous system changes, all of which are considered structural. The second is related to “software” changes and pertains to improvements in the capacity to use the structures. These are considered cognitive, and they occur as a consequence of developing processing-information capabilities (Connolly, 1977; Thomas, 1980). Learning Benefits of Self-Controlled Knowledge of Results in 10-Year-Old Children

TECHNICAL VARIATION IN A SAMPLE OF HIGH LEVEL JUDO PLAYERS

Technical actions performed by two groups of judokas who won medals at World Championships and Olympic Games during the period 1995–2001 were analyzed. In the Super Elite group (n = 17) were the best athletes in each weight category. The Elite group (n = 16) were medal winners who were not champions and did not win more than three medals. Super Elite judokas used a greater number of throwing techniques which resulted in scores, even when expressed relative to the total number of matches performed, and these techniques were applied in more directions than those of Elite judokas. Further, the number of different throwing techniques and the variability of directions in which techniques were applied were significantly correlated with number of wins and the number of points and ippon scored. Thus, a greater number of throwing techniques and use of directions for attack seem to be important in increasing unpredictability during judo matches.

The Contextual Interference Effect in Acquisition of Dart-Throwing Skill Tested on a Transfer Test with Extended Trials:

Previous studies of contextual interference have shown that practicing several motor skills randomly (high contextual interference) facilitates retention and transfer in comparison to practicing the same tasks in a blocked order (low contextual interference). However, many studies have not supported this phenomenon in motor learning, and some researchers have questioned whether the effect can be tested by using only a few trials on the transfer test. The present study used a different methodological approach in which the number of test trials was increased to assess whether the contextual interference effect is sustained over an extended number of trials in the transfer phase. Undergraduate students (N = 32) were randomly allocated to either a blocked or random group. The participants practiced 80 acquisition trials in the dart-throwing task from distances of 300 cm and 420 cm, using two different grips. The transfer test after a 10-min. interval consisted of 40 trials with a new grip at a distance of 360 cm. The results did not support the contextual interference effect since there were no significant differences between groups on transfer. These findings suggest that the contextual interference effect may not be a global learning phenomenon which can be generalized to all learning situations.

Modularity and hierarchical organization of action programs in human acquisition of graphic skills

If motor or action programs become modules with practice their defining features (e.g. relative timing) should remain relatively invariant in new tasks. To test this hypothesis 24 adults practiced a graphic skill over 100 trials and were transferred to a more complex task enclosing the practiced figure. The data acquired by a digital tablet resulted in total movement and total pause times to draw the figure indicating skill acquisition and variability measures of relative timing and pause time and sequencing referring to features that identify a module. Being transferred to a more complex task did not lead to significant increases in the time to perform the criterion figure embedded in the new pattern. Modularity was evidenced by the stability of relative timing and sequencing shown in the performance of the criterion figure. Hence, it might be that action programs become modules that are then hierarchically organized to form more complex skills.

Does the Contextual Interference Effect Last over Extended Transfer Trials

The contextual interference effect (random practice yields better transfer and retention compared to blocked practice) detected in a study of 24 boys and 33 girls randomly selected (M age = 10.5 yr., SD = .6) performing a linear positioning motor task seemed to dissipate in extended transfer trials.

Risco cardiovascular e prática de atividade física em crianças e adolescentes de Muzambinho/MG: influência do gênero e da idade

INTRODUCTION AND OBJECTIVE: Cardiovascular disease begins at infancy and it has been linked to the presence of cardiovascular risk factors (CRF). Prevalence of these factors varies a lot among different Brazilian populations and has been mostly studied in big and medium size cities. Thus, this study assessed the prevalence of CRF and physical activity (PA) in children and adolescents from Muzambinho, a small city in the state of Minas Gerais. METHODS: 205 subjects (7 to 18 years - 108 males) were studied. Body weight and height, glycemia, cholesterolemia, blood pressure (BP), and PA were measured. Comparisons were made by Qui-square test. RESULTS: Obesity and altered values of BP, glycemia, and cholesterolemia were found, respectively, in 19, 11, 5 and 15% of the subjects. There was no difference between genders, while the prevalence of smokers, drinkers, altered BP, and inactivity increased with age. Seventy-nine percent of the subjects practiced community PA; 10% occupational PA; 97% physical education classes; 72% PA during school recess; and 90% leisure time PA. Ninety-two percent of them were active. Occupational PA was higher in girls, and increased with age in boys. Leisure time and during school recess PA decreased with age in both genders. CONCLUSION: Except for physical inactivity, prevalence of CRF was high, did not differ between genders, and increased with age. High levels of all kinds of PA were found; they differed between genders, and decreased with age.

Constant-Random Practice and the Adaptive Process in Motor Learning with Varying Amounts of Constant Practice

The adaptive process in motor learning was examined in terms of effects of varying amounts of constant practice performed before random practice. Participants pressed five response keys sequentially, the last one coincident with the lighting of a final visual stimulus provided by a complex coincident timing apparatus. Different visual stimulus speeds were used during the random practice. 33 children (M age = 11.6 yr.) were randomly assigned to one of three experimental groups: constant-random, constant-random 33%, and constant-random 66%. The constant-random group practiced constantly until they reached a criterion of performance stabilization — three consecutive trials within 50 msec. of error. The other two groups had additional constant practice of 33 and 66%, respectively, of the number of trials needed to achieve the stabilization criterion. All three groups performed 36 trials under random practice; in the adaptation phase, they practiced at a different visual stimulus speed adopted in the stabilization phase. Global performance measures were absolute, constant, and variable errors, and movement pattern was analyzed by relative timing and overall movement time. There was no group difference in relation to global performance measures and overall movement time. However, differences between the groups were observed on movement pattern, since constant-random 66% group changed its relative timing performance in the adaptation phase.

Relative frequency of knowledge of results and task complexity in the motor skill acquisition

The aim of this study was to investigate the effects of knowledge of results (KR) frequency and task complexity on motor skill acquisition. The task consisted of throwing a bocha ball to place it as close as possible to the target ball. 120 students ages 11 to 13 years were assigned to one of eight experimental groups according to knowledge of results frequency (25, 50, 75, and 100%) and task complexity (simple and complex). Subjects performed 90 trials in the acquisition phase and 10 trials in the transfer test. The results showed that knowledge of results given at a frequency of 25% resulted in an inferior absolute error than 50% and inferior variable error than 50, 75, and 100% frequencies, but no effect of task complexity was found.

Self-Controlled Practice Enhances Motor Learning in Introverts and Extroverts

Purpose: The purpose of the present study was to investigate the effects of self-controlled feedback on the learning of a sequential-timing motor task in introverts and extroverts. Method: Fifty-six university students were selected by the Eysenck Personality Questionnaire. They practiced a motor task consisting of pressing computer keyboard keys in a specific spatial and temporal pattern. The experiment consisted of practice, retention, and transfer phases. The participants were distributed into 4 groups, formed by the combination of personality trait (extraversion/introversion) and type of feedback frequency (self-controlled/yoked). Results: The results showed superior learning for the groups that practiced in a self-controlled schedule, in relation to groups who practiced in an externally controlled schedule, F(1, 52) = 4.13, p < .05, η2 = .07, regardless of personality trait. Conclusion: We conclude that self-controlled practice enhances motor learning in introverts and extroverts.

“Timing” coincidente em tarefas complexas: estudo exploratório do desempenho de adultos de diferentes idades em diferentes velocidades de estímulo visual

O objetivo desse estudo foi investigar o desempenho em uma tarefa complexa de “timing” coincidente em funcao da idade e da velocidade do estimulo visual. Os participantes foram 58 adultos voluntarios de ambos os sexos (38 adultos jovens com idades entre 19 e 23 anos e 20 adultos maduros com idades entre 35 e 50 anos). Cada grupo de adultos foi dividido em tres subgrupos de acordo com uma velocidade do estimulo visual (lenta, moderada e rapida). A tarefa consistiu em tocar cinco alvos em uma ordem pre-estabelecida em integracao a um estimulo visual. A variavel dependente foi o erro (absoluto, variavel e constante). Os dados foram analisados por meio de estatistica nao-parametrica, sendo que a ANOVA de Kruskal-Wallis apontou diferenca entre os grupos apenas no erro constante. Todavia, o teste U de Mann-Whitney, com o p ajustado com o procedimento de Bonferroni nao foi capaz de identificar entre quais grupos houve diferenca. Pode-se concluir que adultos jovens e maduros obtiveram similar desempenho em uma tarefa complexa de “timing” coincidente, independentemente da velocidade do estimulo visual.