共查询到20条相似文献，搜索用时 31 毫秒
1.
Kenneth C. Lersten 《Research quarterly for exercise and sport》2013,84(4):1013-1019
Abstract The effects of practice and the passage of time on individual differences (true-score variance) and intra-individual variation were investigated. One hundred and twenty male university students were tested on a Koerth type pursuit rotor. One group was tested on six days spaced over a three-week period. Another group performed the same motor task two days only—test and retest being separated by an interval of three weeks. Each day of practice was the same for both groups—sixty 15-second trials separated by a 10-second intertrial rest. It was concluded that true-score variance as well as intra-individual variance tend to parallel the initial increases in performance and then stabilize in later practice. Since the true-score variance increased greatly as compared with intra-individual variance in early performance, the correlation between adjacent trials increased. The effect of the lay-off was to increase both individual differences and intra-individual variance to a substantial and statistically significant degree. 相似文献
2.
Abstract Research on the benefits of distributed practice for the acquisition and retention of motor skills has a long history. The majority of this research has involved skill acquisition of continuous tasks. However, there is some evidence to suggest that distribution of practice effects are quite different for discrete tasks than for continuous tasks. In the present study, we used a single task, formed discrete and continuous versions of the task, and examined how acquisition and retention were affected by the length of inter-trial interval. The basic task was a movement timing task that involved either one timing estimate per trial (the “discrete” version) or twenty successive estimates per trial (the “continuous” version). Separate groups of subjects learned one version of the task under either distributed (25 s inter-trial intervals) or massed (0.5 s inter-trial intervals) practice conditions. Both massed and distributed retention trials were performed on the same version of the task according to a double transfer design. The results confirmed the apparent disparity: Acquisition and retention were facilitated by distributed practice on the continuous task, but by massed practice on the discrete task. These results were discussed in terms of the role of the inter-trial interval in discrete and continuous tasks. 相似文献
3.
Bartlett R Wheat J Robins M 《Sports biomechanics / International Society of Biomechanics in Sports》2007,6(2):224-243
This paper overviews the importance for sports biomechanics of movement variability, which has been studied for some time by cognitive and ecological motor skills specialists but, until quite recently, had somewhat been overlooked by sports biomechanists. The paper considers biomechanics research reporting inter- and intra-individual movement variability in javelin and discus throwing, basketball shooting, and locomotion. The overview does not claim to be comprehensive and we exclude such issues as the theoretical background to movement and coordination variability and their measurement. We overview evidence, both theoretical and empirical, of inter-individual movement variability in seeking to achieve the same task goal, in contrast to the concept of "optimal" movement patterns. Furthermore, even elite athletes cannot reproduce identical movement patterns after many years of training, contradicting the ideas of motor invariance and "representative" trials. We contend that movement variability, far from being solely due to neuromuscular system or measurement "noise"--as sports biomechanists may have previously supposed--is, or could be, functional. Such functionality could allow environmental adaptations, reduce injury risk, and facilitate changes in coordination patterns. We conclude by recommending that sports biomechanists should focus more of their research on movement variability and on important related topics, such as control and coordination of movement, and implications for practice and skill learning. 相似文献
4.
Sally J. Phillips David L. Kelley Spiros G. Prassas 《Research quarterly for exercise and sport》2013,84(2):197-200
Abstract The contextual interference (CI) effect has been replicated many times since its first demonstration by Shea and Morgan (1979) in the motor learning domain (see Brady, 1998; Magill&;Hall, 1990). The CI effect is characterized by the observation that experiencing greater interference during acquisition is detrimental to immediate performance but enhances delayed performance as measured on retention or transfer tests. High CI is most often created by random practice in which the learning of multiple tasks occurs in a single training. In contrast, low CI is frequently created by using a blocked practice format in which all the practice trials of one task are completed before another task is introduced. One theoretical account that has been forwarded to account for the CI effect is labeled the action plan reconstruction hypothesis (Lee&;Magill, 1983, 1985). This position intimates that before a movement occurs an “action plan” must be prepared. In blocked practice, a previously prepared “action plan” is readily available from trial to trial, but it suffers from lack of attention on trials following initial retrieval from working memory. In random practice, however, each time a task must be executed a “reconstruction” of the action plan must be processed, because the interchange of information from trial to trial never allows the same information to remain in working memory for an extended amount of time. Presumably, the additional trial-to-trial preparation used by the random practice participant during practice results in a more resilient memory representation that better supports long-term recall efforts compared to their blocked practice counterparts. 相似文献
5.
John Lucas 《Research quarterly for exercise and sport》2013,84(1):41-47
Abstract The generality of the variability in practice prediction, arising from Schmidt's schema theory (1975) of motor learning was tested on young children. More specifically, the structure of the variability session and its subsequent influence on transfer performance to a novel variation of the task was examined. Children tossed a weighted bean bag to a fixed target location. Three groups experienced variability in practice with four bean bags of varying weights (3, 4, 5, and 6 oz.); however, the trial-by-trial presentation of each weight was different for each group. One group received a random presentation of each weight from trial to trial while another experienced random presentations of a weight for blocks of three trials. The third variability group received blocked practice with six trials per block for each weight. All variability groups experienced the same amount of practice at each weight. A constant practice group experienced only a single weight. Following 24 practice trials, all subjects transferred outside the range of previous experience, receiving three trials with one of two possible test weights (2 oz. or 7 oz.). The results indicated that the variability group practicing with blocks of three trials at each variation led to superior performance at transfer to novel variations of the task. Overall, the experiment suggested that transfer performance for children is affected by the appropriate structure of variable practice which formulates the schemata for movement production. 相似文献
6.
Abstract The aim of the present study was to determine if two levels of task similarity influenced acquisition, retention, and transfer performance of three simple motor skills. Sixty right-handed subjects were randomly assigned to one of five (n = 12) experimental conditions. Each subject performed 72 trials during acquisition. Twenty-four trials were recorded for each movement task. Following a 5-min unfilled retention interval, subjects performed 4 trials on each task before completing 12 transfer trials of a novel movement. Contextual interference effects for acquisition and retention were supported for low but not high similarity tasks. Further, the results suggest that a different memory representation exists for high and low similarity tasks. 相似文献
7.
Mary Alice Brennan 《Research quarterly for exercise and sport》2013,84(3):293-295
Abstract Recent research (Lee &; Weeks, 1987; Weeks, Lee, &; Elliott, 1987) investigating the processes responsible for the contextual interference phenomenon has used a modified short-term motor retention paradigm to support the reconstruction explanation (Lee &; Magill, 1985; Magill, 1989; Magill &; Hall, 1990). The present experiment was an extension of these experiments in which forgetting of an acquisition task was induced through performance of either a similar or dissimilar distractor task during the intertrial interval. The effects of an extra practice trial with the acquisition task as well as no activity during the intertrial interval were also investigated. In addition, forgetting of the acquisition task was assessed prior to a reconstruction trial, which immediately preceded a 2-min filled retention interval. Both similar and dissimilar distractor tasks caused equivalent amounts of forgetting of the acquisition task prior to the reconstruction trial. However, retention of the acquisition task was significantly improved if its reconstruction occurred following forgetting due to interference from performance of a similar distractor task. These findings suggest forgetting and subsequent reconstruction alone are not sufficient for improved retention. These processes must occur in the context of a similar task for improved retention. 相似文献
8.
Roger Bartlett Jon Wheat Matthew Robins 《Sports biomechanics / International Society of Biomechanics in Sports》2013,12(2):224-243
This paper overviews the importance for sports biomechanics of movement variability, which has been studied for some time by cognitive and ecological motor skills specialists but, until quite recently, had somewhat been overlooked by sports biomechanists. The paper considers biomechanics research reporting inter- and intra-individual movement variability in javelin and discus throwing, basketball shooting, and locomotion. The overview does not claim to be comprehensive and we exclude such issues as the theoretical background to movement and coordination variability and their measurement. We overview evidence, both theoretical and empirical, of inter-individual movement variability in seeking to achieve the same task goal, in contrast to the concept of “optimal” movement patterns. Furthermore, even elite athletes cannot reproduce identical movement patterns after many years of training, contradicting the ideas of motor invariance and “representative” trials. We contend that movement variability, far from being solely due to neuromuscular system or measurement “noise” – as sports biomechanists may have previously supposed – is, or could be, functional. Such functionality could allow environmental adaptations, reduce injury risk, and facilitate changes in coordination patterns. We conclude by recommending that sports biomechanists should focus more of their research on movement variability and on important related topics, such as control and coordination of movement, and implications for practice and skill learning. 相似文献
9.
Distribution of practice in motor skill acquisition: different effects for discrete and continuous tasks 总被引：1，自引：0，他引：1
Research on the benefits of distributed practice for the acquisition and retention of motor skills has a long history. The majority of this research has involved skill acquisition of continuous tasks. However, there is some evidence to suggest that distribution of practice effects are quite different for discrete tasks than for continuous tasks. In the present study, we used a single task, formed discrete and continuous versions of the task, and examined how acquisition and retention were affected by the length of inter-trial interval. The basic task was a movement timing task that involved either one timing estimate per trial (the "discrete" version) or twenty successive estimates per trial (the "continuous" version). Separate groups of subjects learned one version of the task under either distributed (25 s inter-trial intervals) or massed (0.5 s inter-trial intervals) practice conditions. Both massed and distributed retention trials were performed on the same version of the task according to a double transfer design. The results confirmed the apparent disparity: Acquisition and retention were facilitated by distributed practice on the continuous task, but by massed practice on the discrete task. These results were discussed in terms of the role of the inter-trial interval in discrete and continuous tasks. 相似文献
10.
Raheem J. Paxton Claudio Nigg Robert W. Motl Marisa Yamashita Richard Chung Jackie Battista 《Research quarterly for exercise and sport》2013,84(3):423-427
Abstract Sixty male college students were given sixty 15-sec. trials on the pursuit rotor learning task. Practice was interrupted halfway through learning by a 10-min. rest period in order to investigate whether or not a reminiscence effect would influence inter-individual differences and intra-individual variation in performance. Results were consistent with previous experimentation in that inter-individual differences increased as a result of both practice and the interpolated rest period. A corresponding effect on intra-individual variation was barely noticeable. 相似文献
11.
Ezio Preatoni Manuela Ferrario Giulia Donà Joseph Hamill Renato Rodano 《Journal of sports sciences》2013,31(12):1327-1336
Abstract This aim of this study was to analyse the nature of movement variability and to assess whether entropy measures may represent a valuable synthetic index of neuromuscular organization. The regularity of kinematic/kinetic time series during race walking, the changes in the structure of intra-individual variability over the test session, and the influence of athletic skill in (inter)national rank athletes were investigated. Motion analysis techniques were used. Sample entropy (SampEn) was adopted to examine fluctuations in lower limb angles and ground reaction forces. The regularity of both original and surrogate time series was assessed and compared, by estimating SampEn, to verify the presence of non-linear features in movement variability. SampEn was statistically lower in the original data than in surrogates. In contrast, the regularity of time series did not change significantly throughout the subsequent intra-individual repetitions. Hip and ankle joint angles and vertical ground reaction force manifested increased entropy for skilled athletes. Results suggest that race walking variability was not only the product of random noise but also contained information about the inherent propriety of the neuro-musculo-skeletal system. Furthermore, they provide some indications about neuromuscular control of the lower limb joints during race walking gait, and about the differences between more and less skilled individuals. 相似文献
12.
Abstract The purpose of these experiments was to investigate further the variable practice effect found by Shea and Kohl (1990). Experiment 1 was an initial attempt to determine the locus of the retention benefits demonstrated by subjects provided variable practice experiences. All groups received 20 acquisition blocks consisting of five test trials per block at a target of 150 N. The interval between test trials was either unfilled or filled, with additional trials consisting of the same target force, variable target forces, or practice on an unrelated motor task. The results indicated retention was not incremented (relative to an unfilled interval) by requiring subjects to perform an unrelated motor task in the intertest–trial interval. However, when the intertest–trial interval was filled with practice on related motor tasks, retention was significantly improved. Experiment 2 assessed the impact of increasing the number of related motor tasks interpolated between test trials. The results indicated filling the intertest–trial interval with one motor task resulted in large retention benefits relative to an unfilled interval. Further increases in the number of related motor tasks (3) interpolated between test trials resulted in only modest increments to retention. The results were consistent with the elaboration perspective proposed by Shea and Zimny (1983). The elaboration perspective proposes that the simultaneous presence of related items in working memory facilitates interitem elaborative and distinctive processing that ultimately results in retention benefits. 相似文献
13.
Recent research (Lee & Weeks, 1987; Weeks, Lee, & Elliott, 1987) investigating the processes responsible for the contextual interference phenomenon has used a modified short-term motor retention paradigm to support the reconstruction explanation (Lee & Magill, 1985; Magill, 1989; Magill & Hall, 1990). The present experiment was an extension of these experiments in which forgetting of an acquisition task was induced through performance of either a similar or dissimilar distractor task during the intertrial interval. The effects of an extra practice trial with the acquisition task as well as no activity during the intertrial interval were also investigated. In addition, forgetting of the acquisition task was assessed prior to a reconstruction trial, which immediately preceded a 2-min filled retention interval. Both similar and dissimilar distractor tasks caused equivalent amounts of forgetting of the acquisition task prior to the reconstruction trial. However, retention of the acquisition task was significantly improved if its reconstruction occurred following forgetting due to interference from performance of a similar distractor task. These findings suggest forgetting and subsequent reconstruction alone are not sufficient for improved retention. These processes must occur in the context of a similar task for improved retention. 相似文献
14.
Abstract Five trials on the stabilometer were administered to 274 EMR children ages 6 to 13 years and 151 normal children ages 6 to 9 years. Older EMR boys and girls had slightly more board movement than younger EMR children whereas there was a tendency for board movement to decrease with age for the normal children. There were no appreciable sex differences between the EMR and the normal age groupings with the exception that board movement of the young EMR boys was significantly less than that of the young and old EMR girls. Normal children had significantly less board movements than EMR children at all age levels. There was some decrease in relative intra-individual variability with increasing age for both EMR and normal children but normal children were more efficient in early learning than EMR children. 相似文献
15.
The aim of the present study was to determine if two levels of task similarity influenced acquisition, retention, and transfer performance of three simple motor skills. Sixty right-handed subjects were randomly assigned to one of five (n = 12) experimental conditions. Each subject performed 72 trials during acquisition. Twenty-four trials were recorded for each movement task. Following a 5-min unfilled retention interval, subjects performed 4 trials on each task before completing 12 transfer trials of a novel movement. Contextual interference effects for acquisition and retention were supported for low but not high similarity tasks. Further, the results suggest that a different memory representation exists for high and low similarity tasks. 相似文献
16.
Nancy L. Struna 《Research quarterly for exercise and sport》2013,84(1):117-135
Purpose This study investigated whether within-task expertise affects the reported asymmetry in execution time exhibited in reactive and self-initiated movements. Method Karate practitioners and no-karate practitioners were compared performing a reverse punch in reaction to an external stimulus or following the intention to produce a response (self-initiated). The task was completed following the presentation of a specific (i.e., life-size image of opponent) or general stimulus and in the presence of click trains or white noise. Results Kinematic analyses indicated reactive movement had shorter time to peak velocity and movement time, as well as greater accuracy than self-initiated movement. These differences were independent of participant skill level although peak velocity was higher in the karate practice group than in the no-karate practice group. Reaction time (RT) of skilled participants was facilitated by a specific stimulus. There was no effect on RT or kinematic variables of the different type of auditory cues. Conclusions The results of this study indicate that asymmetry in execution time of reactive and self-initiated movement holds irrespective of within-task expertise and stimulus specificity. This could have implications for training of sports and/or relearning of tasks that require rapid and accurate movements to intercept/contact a target. 相似文献
17.
This study compared reactive agility between higher-standard (n = 14) and lower-standard (n = 14) Australian footballers using a reactive agility test incorporating a life-size video image of another player changing direction, including and excluding a feint. Mean agility time in the feint trials was 34% (509 ± 243 ms; p < 0.001; effect size 3.06) longer than non-feint trials. In higher-standard players, agility time was shorter than for lower-standard players in both feint (114 ± 140 ms; p = 0.18; effect size 0.52; likely beneficial) and non-feint (32 ± 44 ms; p = 0.22; effect size 0.47; possibly beneficial) trials. Additionally, the inclusion of a feint resulted in movement time increasing over three times more in the lower-standard group (197 ± 91 ms; p = 0.001; effect size 1.07; almost certainly detrimental) than the higher-standard group (62 ± 86 ms; p = 0.23; effect size 0.66; likely detrimental). There were weak correlations between the feint and non-feint trials (r = -0.13-0.14; p > 0.05), suggesting that reactive agility involving a feint is a unique skill. Also, higher-standard players are more agile than their lower-standard peers, whose movement speed deteriorates more as task complexity increases with the inclusion of a feint. These results support the need for specific training in multi-turn reactive agility tasks. 相似文献
18.
Abstract This study compared reactive agility between higher-standard (n = 14) and lower-standard (n = 14) Australian footballers using a reactive agility test incorporating a life-size video image of another player changing direction, including and excluding a feint. Mean agility time in the feint trials was 34% (509 ± 243 ms; p < 0.001; effect size 3.06) longer than non-feint trials. In higher-standard players, agility time was shorter than for lower-standard players in both feint (114 ± 140 ms; p = 0.18; effect size 0.52; likely beneficial) and non-feint (32 ± 44 ms; p = 0.22; effect size 0.47; possibly beneficial) trials. Additionally, the inclusion of a feint resulted in movement time increasing over three times more in the lower-standard group (197 ± 91 ms; p = 0.001; effect size 1.07; almost certainly detrimental) than the higher-standard group (62 ± 86 ms; p = 0.23; effect size 0.66; likely detrimental). There were weak correlations between the feint and non-feint trials (r = ?0.13–0.14; p > 0.05), suggesting that reactive agility involving a feint is a unique skill. Also, higher-standard players are more agile than their lower-standard peers, whose movement speed deteriorates more as task complexity increases with the inclusion of a feint. These results support the need for specific training in multi-turn reactive agility tasks. 相似文献
19.
Craig A. Wrisberg Timothy P. Winter Jolynn S. Kuhlman 《Research quarterly for exercise and sport》2013,84(4):369-374
Abstract In the present study experimental subjects practiced variations in movement distance and/or movement time during training trials on a closed timing task. Control subjects trained with single distance-time combinations. During transfer trials all subjects attempted (without knowledge of results) a distance-time combination that was different (except in the case of one control condition) from any performed during training. The results revealed that the timing accuracy of the two experimental conditions that practiced a variety of times was significantly poorer than that of most of the other conditions during the training phase. However, transfer analyses revealed several significant differences between the performance of variable-trained and constant-trained conditions, in all cases favoring the former. It was concluded that the transfer benefits of variable practice are (a) not due to the particular movement component selected for variation during training, and (b) to some extent always determined by the similarity of training and transfer conditions experienced by constant-practice subjects. 相似文献
20.
Franklin M. Henry 《Research quarterly for exercise and sport》2013,84(2):155-159
Abstract Independent estimates of the errors of measurement and the intra-individual variations have been made for arm strength (Smedley dynamometer) and vertical jumping (Henry apparatus). The intra-individual variations are much larger than the measurement errors; thus they constitute the chief factor that determines test-retest reliability in these two physical performances. The tolerable error for measuring strength is ± 0.82 kg.; for jumping it is ± 0.5 in. In order to avoid loss of accuracy, it is necessary to read the dial or scale with approximately twice this precision. The method of computing test-retest reliability as the ratio of “true score” variance to total variance is found to underestimate the coefficient when the variability of test and retest scores differs by more than 15 percent. A formula for correcting this attenuation is presented. 相似文献