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1.
Abstract

Coincidence-anticipation performance has been found to vary with changes in the speed of the task's stimulus. This may be due to bias effects. The present study was designed to investigate the existence of directional error, its persistence after extended practice, and its occurrence upon transfer to new contextual stimuli. Two groups of 20 women athletes each were tested for 270 trials over 3 days on a Bassin anticipation task. One group judged stimulus speeds of 2, 3, and 4 mph and the other group speeds of 2, 4, and 6 mph. Both groups improved during training, but tended to respond late, less accurately, and more variably to the slowest speed. Following a 30-trial warmup on Day 4, the second group transferred to the same speeds given the first group. Following transfer, the Transfer Group demonstrated increased directional bias to the slowest stimulus speed despite having seen this speed throughout training. By the second block of trials following transfer, however, they were performing at an error level similar to that of the Control Group. The present findings are in agreement with those concerning psychophysical judgments, and suggest that skill acquisition may be subject to bias effects if the task involves judgments of varying speeds.  相似文献   

2.
Abstract

Four groups of 20 subjects were given 35 practice trials on a discrete motor task. On Trials 3 through 25 each of three experimental groups performed with either a 1, 3, or 6 lb. wristlet strapped to their wrists. Trials 1 and 2 and Trials 26 through 35 were performed under control conditions. Comparisons made of the three experimental groups with a group which practiced under control conditions throughout, revealed that the added physical work significantly depressed performance but did not affect learning. Analysis of the data after rest revealed that the groups did not differ significantly in the amount of learning, slopes of the curves, or means of the test trials. Reminiscence was found to be a function of the amount of physical work.  相似文献   

3.
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   

4.
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   

5.
Abstract

Two matched groups of 10 subjects each were employed to assess possible central facilitation effects over 4 weeks of training. Each of the 12 training sessions consisted of 20 trials of maximum isometric wrist flexion for 5 sec. with a 30-sec. rest period between trials. Two experimental conditions were used. On alternate sessions condition one consisted of 20 trials with odd-numbered trials being unilateral and even-numbered trials being simultaneous bilateral efforts. Condition two consisted of the first 15 trials being unilateral and the last 5 trials simultaneous bilateral. The right limb in Group I and the left limb in Group II constituted the criterion measures. Central facilitation effects due to simultaneous bilateral isometric wrist contractions were: (a) not present initially and (b) not elicited through the 4 weeks of training. The finding held for both dominant and nondominant limbs and for fatigued and nonfatigued states.  相似文献   

6.
Abstract

Three hundred male subjects, assigned in systematic rotation to five experimental groups (N = 60 in each) which differed in amount of distribution of practice, were tested on a discrete-trial motor learning task, the peg turn. All subjects were given 120 practice trials (60 trials a day), on two days separated by a 48-hour rest. Even though the peg turn task is inherently distributed, reminiscence did occur when the massing was made as large as practically possible. The amount of reminiscence depended upon the stage of practice. Warm-up decrement occurred in the peg turn under both massed and distributed practice conditions; the longer the rest, the greater the amount. Performance of the task under nonrhythmical conditions reduced the development of “set” during practice and thus decreased the amount of warm-up decrement after rest. Increased amounts of massing did have a deleterious effect on performance, but did not reduce the amount learned.  相似文献   

7.
Abstract

The efficiency of two practice schedules was examined on two large muscle motor tasks. There were four groups of subjects (N = 160); each individual in a group performed on one of the two motor tasks under one of the two conditions. Distributed practice consisted of alternating 30-second trials of practice and rest; massed practice was continuous for 8 minutes. Comparisons made during the last minute of practice prior to the rest pause revealed that the massed groups had significant decrements in performance level. In contrast, after the rest period, when both groups were on a distributed schedule, no difference was found in the amount of learning. Learning was found to be a function of the number of trials and independent of the conditions of practice.  相似文献   

8.
Abstract

The purpose of this study was to determine if there were differences in learning to perform a novel motor task between two equated groups: one group was subjected to learning the task immediately following a heavy physical work bout on a bicycle ergometer; the other group was subjected to learning the task with no imposed physical exercise. It was found that the subjects who practiced the stabilometer exercise in a fatigued state performed significantly better than subjects in the control group except for test 4. The experimental group also performed significantly better than the control group during the 5th test which was performed without any fatiguing task. It appears from this study that the fatigue state of the learner had a favorable influence on both performance and learning of certain novel motor skills.  相似文献   

9.
ABSTRACT

This study examined the simultaneous effects of relative age and biological maturity status upon player selection in an English professional soccer academy. A total of 202 players from the U9 to U16 age groups, over an eight-year period (total of 566 observations), had their relative age (birth quarter) and biological maturity (categorised as late, on-time or early maturing based upon the Khamis-Roche method of percentage of predicted adult height at time of observation) recorded. Players born in the first birth quarter of the year (54.8%) were over-represented across all age groups. A selection bias towards players advanced in maturity status for chronological age emerged in U12 players and increased with age; 0% of players in the U15 and U16 age group were categorised as late maturing. A clear maturity selection bias for early maturing players was, however, only apparent when the least conservative criterion for estimating maturity status was applied (53.8% early and 1.9% late maturing in the U16 age group). Professional football academies need to recognise relative age and maturation as independent constructs that exist and operate independently. Thus, separate strategies should perhaps be designed to address the respective selection biases, to better identify, retain and develop players.  相似文献   

10.
Abstract

This study was made to determine the influence of five selected motive-incentive conditions upon the effectiveness of a 6-week isometric training program for the development of strength in the elbow flexor muscle group. Data were obtained from an initial test, from each training session, and from a final test. The mean gains in best strength scores from the initial to the final test were statistically significant (p = .05) for all five motive-incentive groups. No significant differences (p = .05) were found between the mean of the scores for the five motive inventive groups obtained during the first training session, during the last training session, from the final test, and from the cumulative scores for the 12 training sessions.  相似文献   

11.
Abstract

It is argued that previous studies of active flexibility have not achieved experimental control. An experiment then is described which achieved experimental control by using daily flexibility training over a 7-day period.

Forty-two female subjects were randomly assigned to one of six treatment groups or a control group. The six treatment groups received proprioceptive neuromuscular facilitation training for six consecutive days with isometric contraction periods of 0 sec, 3 sec, or 6 sec. Three of the treatment groups followed an active regime (concentric contraction of the agonists) and three a passive regime. All subjects were pretested for active flexibility on Day 1. They were also posttested after training on Day 6, and without training on Day 7. A two factor multivariate analysis of covariance with trend analysis on the period of isometric contraction factor indicated a significant positive linear trend for this factor, approximate F(2, 28) = 7.90, p < .002, together with a significant interaction between this linear trend and the active-passive regime factor, approximate F(2, 28) = 3.81, p < .034. Follow-up tests revealed that this interaction was due to larger gains in active flexibility being associated with longer periods of isometric contraction in the active groups, but not in the passive groups.  相似文献   

12.
Abstract

Ten moderately well-conditioned male students at the University of Toledo ran on a treadmill, fully attired in football equipment, with an environmental temperature of 90 F and relative humidity of 70%. Each subject was partially acclimatized and then exposed to the experimental conditions on five consecutive days (balanced Latin square). Four 1-liter water replacement schedules (designed to test specific hypotheses), and a control of no water, served as five levels of the independent variable. Data were collected on rectal temperature, heart rate, pulse pressure, specific gravity changes for whole blood and for plasma, and sweat loss. Results showed that water ingestion early during the work session combated the effects of heat stress better than late administration; however, this advantage was reduced toward the end of the work session. The results were mixed concerning the relative merits of ingesting the water in one or two administrations.  相似文献   

13.
Abstract

This study investigated the effects of sex and athletic status on reaction latencies and movement time. One hundred subjects, categorized into five groups of 20 subjects each—male athletes (MA), female athletes (FA), male nonathletes (MNA), female nonathletes (FNA), and control group (CG)—were tested over a period of five consecutive days. Several different types of incentives were used to ensure that subjects provided the fastest times possible. Two blocks of 25 trials were administered to each subject on each day. A 2 × 2 × 2 × 5 × 2 mixed factorial analysis of variance was used to test for between-subject differences of group (experimental/control), sex, and athletic status and for within-subject differences of days and blocks. The four dependent variables were reaction time (RT) mean, RT consistency, movement time (MT) mean, and MT consistency. Results did not support the classic finding of male superiority over females in RT/MT or athletes' superiority over nonathletes. Evidence of athletic superiority emerged, but for the first day of practice only. As subjects were allowed extended practice over a 5-day test period in which knowledge of results (KR) and other incentives were provided, differences in the experimental groups disappeared. Sex was the predominant factor in consistency, with males being less variable in RT (p = .02) performance than females. There were no sex differences in MT consistency.  相似文献   

14.
Abstract

Forty-five children from two intact kindergartens in one school were randomly assigned by sex to (a) an experimental group which received a movement program that included 120 min of guided practice in the overhand throw; or (b) a control group which received the same movement program but no exposure to the throw. A third group (N = 24), randomly selected by sex from a comparable school, received no movement program. Before and after the eight-week instructional period, ten trials of each child's overhand throw for force were filmed. Horizontal ball velocities were simultaneously recorded. ANOVAs on pre- and posttest ball velocities for each sex within each treatment group revealed no significant practice effect over ten trials (p > .05); thus, the trial mean was used as each subject's score. Two-way ANOVAs (treatment X sex) on the pre- and posttest data indicated no significant velocity differences (p > .05) between groups either before or after instruction. Boys had significantly greater velocities than girls (p < .05). Eight weeks of instruction that included 120 min of guided practice in the overarm throw did not significantly change the ball velocities of kindergarten children when compared to two groups with no formal throwing experience.  相似文献   

15.
Background: The advent of technology use in physical education is upon us. But the implications of using exergames as a substitute for traditional physical education instruction for some students raise questions. Although exergames have the potential to increase energy expenditure and motivation in some children, it is less clear whether they can provide skill acquisition benefits that are similar to those found in traditional physical education.

Purpose: In a previous experiment from our laboratory, we found that deliberate practice can significantly reduce the planning time required for lateral arm movements. The purpose of this study was to determine if exergames can produce a similar effect, by reducing the processing time required for children to initiate arm movements to the contralateral and ipsilateral space.

Participants and setting: Thirty children (boys?=?15, girls?=?15), between the ages of 7 and 12 years, participated in a pre- and post-test each taking 30?min and one 30?min treatment session in a university laboratory.

Research design: A repeated measures design was employed to test the effects of deliberate laterality practice on processing speed. Children were randomly assigned (n?=?10) to either a Nintendo Wii tennis contralateral movement experimental group, Nintendo Wii bowling ipsilateral movement experimental group, or handheld video-game control group. Each child participated in one 30?min treatment session.

Data collection: Upper extremity choice reaction time (RT) was measured through 27 goal-directed aiming movements for each arm separately, during the pre-test and post-test. The stimulus–response trials occurred in three randomly presented directions (ipsilateral, contralateral, and midline).

Data analysis: A 3 (treatment group)?×?2 (age group)?×?2 (test)?×?3 (direction) mixed design analysis of variance with repeated measures on the last two factors was used to test for significant differences, with an alpha level set at 0.05.

Findings: There were no significant treatment effects on RT across all groups indicating that a short bout of exergame training was unsuccessful in improving lateral movement processing.

Conclusions: Deliberate laterality practice using exergames did not improve the motor processing speed of lateral arm movements in the same manner of traditional physical education as indicated by our previous research. Explanations as to why exergames do not exhibit the same positive transfer for skill acquisition as traditional physical education instruction are discussed within this paper.  相似文献   

16.
Abstract

The purpose of this study was to examine the strength-decrement fatigue effects in 14 muscle groups of the trunk and lower extremities resulting from a sub-maximal treadmill run at seven miles per hour for a period of ten minutes on a horizontal plane. Only two muscle groups, the hip outward rotators and the trunk flexors, were fatigued sufficiently to cause a significant strength decrement; a third muscle group, the knee flexors, had a loss in mean strength which approached the .05 level of confidence.  相似文献   

17.
Abstract

In two experiments we examined changes in the perception of action possibilities as a function of exertion. In Experiment 1, participants repeatedly climbed on a climbing wall in a series of trials that progressively increased in number to 10 trials, resulting in increased exertion. Before and during climbing, the participants judged their maximum reaching height and perceived exertion. On a separate day, participants climbed another 10 trials while performing actual maximum reaches. Higher perceived exertion was associated with decreases in perceived maximum reach while the actual reaches did not decrease. However, the perceptual changes occurred early during task execution when the participants were not yet fatigued. When exertion set in, neither perceived nor actual maximum reaching appeared to be affected. In Experiment 2, we included exhaustion trials. The findings replicated the early changes in perception observed in Experiment 1, which may be explained by hands-on experience with the task. Furthermore, while climbing to exhaustion, perceptual judgements largely changed in keeping with changes in the actual maximum reach. Thus, there appeared to be a functional relationship between participants' actual action capabilities, rather than their state of physical fatigue per se, and perceived action possibilities.  相似文献   

18.
Abstract

The purpose of this investigation was to determine whether combining two mental preparation strategies would be more effective in enhancing performances than a single strategy. Subjects (n = 40) practiced on a basketball free throw task (20 shots) using one of the following mental preparation strategies: (a) imagery, (b) relaxation, (c) relaxation plus imagery, (d) placebo control. To simulate game conditions, subjects were allowed only 10 s in which to use their mental preparation strategy. After the practice session, subjects shot 20 test free throws using their designated technique. Results indicated a significant main effect with the imagery group performing significantly better than the placebo control group although there were no specific differences between the three experimental groups. The results are discussed in terms of potential variables mediating the effectiveness of imagery in enhancing sport performance, and future directions for research are offered.  相似文献   

19.

Reduced feedback during practice has been shown to be detrimental to movement accuracy in children but not in young adults. We hypothesized that the reduced accuracy is attributable to reduced movement parameter learning, but not pattern learning, in children. A rapid arm movement task that required the acquisition of a motor pattern scaled to specific spatial and temporal parameters was used to investigate the effects of feedback (FB) frequency (100% vs. 62% faded) on motor learning differences between 19 school-age children and 19 young adults. Adults and children practiced the task for 200 trials under the 100% or faded FB condition on Day 1 and returned on Day 2 for a no-FB retention test. On the retention test, children who practiced with reduced feedback performed with greater temporal parameter errors, but not pattern error, than children who received frequent feedback. Motor skill learning in children is influenced by feedback frequency during practice that affects parameter learning but not pattern learning.  相似文献   

20.
Abstract

Male volunteers (N=80) were randomly assigned to either a control or a mental practice group for the learning of three motor skills, the hock swing to a horizontal bar, jump-foot, and soccer hitch kick. All subjects were tested individually on each of the skills but one group engaged in five directed mental practice sessions spaced over a period of 5 days prior to being tested. Significant differences between groups in initial trial success were obtained for the hock swing but not for the other two skills. After physical practice was introduced, the mental practice group required fewer trials to achieve success in the hock swing and the jump-foot but not in the soccer hitch kick. It was concluded that the effectiveness of mental practice without prior physical practice is specific to the skill and is more pronounced for simpler skills.  相似文献   

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