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1.
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2.
Abstract

The present study attempted to determine whether the nature of training experiences influences the development of coincident timing skill in young children. The task involved visual tracking of a moving light sequence and a 43 cm arm movement to a padded target. Subjects attempted to tap the target coincident with the completion of the light sequence. Sixty first grade children were randomly assigned to one of five groups, with an equal number of males and females in each group. Subjects assigned to the training groups received 48 trials on each of two days, with stimulus speeds that were either slow (179 cm/sec or 4 mph), fast (313 cm/sec or 7 mph), varied-random (179, 224, 268, 313 cm/sec or 4, 5, 6, 7 mph), or varied-blocked (i.e., 6 consecutive trials with one speed before changing to another). Control subjects performed a neutral coloring activity during the training phase of the experiment. All subjects were then given 10 trials on a third day with each of two stimulus speeds not experienced previously; one slow (134 cm/sec or 3 mph) and one fast (358 cm/sec or 8 mph). During transfer trials all groups were more accurate with the fast than with the slow speed stimulus. Training method mattered most during slow speed transfer trials, with the most accurate performance demonstrated by the group receiving varied-blocked speeds during training. The least effective methods were fast speed training, especially for males, and varied-random speed training. It was concluded that training sessions for the development of coincident timing skill in young children should emphasize slower speed stimuli and blocking of additional speeds which are more rapid.  相似文献   

3.
Abstract

Five highly skilled canoe racers performed three trials each at race pace using a conventional straight canoe paddle and a modified paddle with the blade angled 15 degrees forward from the shaft. The use of the straight paddle resulted in a mean velocity of 290 cm/sec whereas the angled paddle resulted in a significantly faster mean velocity of 306 cm/sec (p<.05). There were no differences in the temporal sequences of the boat velocities. There were no significant differences in the time the paddles were in the air between strokes. It was also determined that the angled paddle had less absolute movement in the water than the straight paddle during the period of greatest boat acceleration. No significant differences were found in paddling technique through absolute measurement and temporal sequence of horizontal displacement of either hand relative to its corresponding shoulder, either shoulder relative to the spine, or the spine relative to the boat.  相似文献   

4.
Abstract

This study examined the impact of high and low proficiency level, transfer distality, and gender on the contextual interference effect with an open skill. Subjects were separated into two levels of proficiency based on performance on a pretest similar to the experimental task. Analysis of error scores during acquisition indicated that the partitioning of subjects according to ability level had been successful. Transfer distality was varied by presenting subjects with two tasks varying in similarity to the acquisition task. Analysis of absolute constant, constant, variable, and total error scores in transfer strongly suggested that subjects' consistency rather than response bias was affected by the experimental variables. The findings suggested that, for the task used in this study, proficiency level does not account for gender differences in the contextual interference effect, as the effect was only reliably found for females. For coincident timing skills, it appears that there may be two distinct conclusions drawn from the results of this study: contextual interference only benefits female subjects' consistency and the effect of contextual interference increases with the distality of transfer, regardless of the subjects' proficiency level.  相似文献   

5.
Abstract

The physical stimulus-psychological response relationship has been described as being either a prothetic or a metathetic continuum. That is, as the stimulus intensity increases, the response magnitude increases (prothetic) or stays the same (metathetic). The first experiment of this study considered this relationship for a movement having the final limb position, or location, as its goal. The second experiment focused on an extent movement. Subjects were tested on a linear positioning apparatus in both experiments using the method of constant stimuli for determining thresholds. On the basis of the Weber ratios and the JND's for the three increasing movement locations and extents, a metathetic continuum was determined as best describing location movements, while a prothetic continuum was considered more appropriate for extent movements. JND's indicated sensitive discrimination for location movements (1.08 to 1.39 cm for 25 to 75 cm locations) and less precise discrimination capability for extent movements (2.49 to 5.76 cm for 25 to 75 cm extents). Results are discussed in terms of their possible implications for addressing issues related to mechanisms subserving active kinesthesis, and in terms of their implications for experimental procedures for learning and memory investigations using discrete positioning responses.  相似文献   

6.
Abstract

The present experiments examined the effects of stimulus velocity, stimulus duration, and stimulus uncertainty on the spatial-temporal structure and timing accuracy of coincident timing responses. The results of Experiment 1 indicated that the response structure for aimed movements differed from that of ballistic movements but response accuracy was comparable for both movement conditions. However, when information concerning the stimulus velocity was provided, the responses to the faster stimuli (i.e., stimuli of shorter duration) appeared to be “speeded up” copies of those to slower stimuli and response accuracy increased as the stimulus velocity increased (i.e., stimulus duration decreased). When the stimulus velocity was not known, subjects initiated a common response for approximately 260 msec and response accuracy appeared to decrease as the stimulus velocity increased (i.e., stimulus duration decreased). Experiment 2 indicated that the stimulus duration rather than the stimulus velocity was the major determiner of both the spatial-temporal structure and timing accuracy and that a very fast and a very slow stimulus will be responded to similarly when the stimulus duration remains constant.  相似文献   

7.
Abstract

The purpose of this study was to determine the relationship between the ability to perform 11 tumbling skills and the ability to diagnose errors of execution in the performance of these same skills. Thirty-two male upper divisional physical education majors at the University of Maryland served as subjects. A knowledge test was administered to the subjects to determine their knowledge of the mechanics of execution for each skill. The subjects' performances of these tumbling skills were photographed and evaluated by expert judges. The subjects diagnosed errors in the execution of each of the 11 skills from a cinematographic presentation of demostrator performances. A significant correlation as expressed by an r = .49 was found between performance ability and diagnostic ability with a significant correlation coefficient of .51 between knowledge and diagnostic ability, however, no significant relationship was indicated between performance ability and knowledge.  相似文献   

8.
Abstract

Two unique methodological strategies were used to investigate the influence of retroactive inhibition on recall within a contextual interference paradigm. Three independent blocked groups, blocked without retroactive inhibition (BL-without), blocked with 18 trials of retroactive inhibition (BL-18), and blocked with 36 trials of retroactive inhibition (BL-36), were created that varied in order of presentation of tasks. By testing a single task in retention and creating three independent blocked groups, varying amounts of retroactive inhibition were produced. This isolated the effects of retroactive inhibition on blocked compared to control and random subjects' retention. The Acquisition Group x Retention Trials interaction indicated that random and BL-without subjects had shorter reaction time than BL-18 and BL-36 subjects. Thus, blocked subjects with retroactive inhibition exhibited a retention deficit compared to BL-without subjects. The results support previous contextual interference findings and suggest that retroactive inhibition influences the retention deficits demonstrated by blocked compared to random subjects in typical contextual interference investigations.  相似文献   

9.
In the light of the intensity coupling effects reported in the literature, subjects' capacities for independently controlling the absolute velocity of their movement at the point of interception was evaluated by asking them to learn to propel orthogonally approaching balls, varying in their speed of approach, into target boxes placed at various distances from the interception point. As required for successful accomplishment of the task, movement velocity was found to be adapted to the distance to be covered, with the near target giving rise to lower velocities and the far target giving rise to higher velocities even when the conditions were presented in random order. Nevertheless, even though target distance accounted for a substantial proportion of the total variance, a small but significant effect of ball approach speed on movement velocity was found, suggesting that intensity coupling is a persistent but modulable phenomenon in interception tasks.  相似文献   

10.
BackgroundNumerous studies about the interaction between footwear (and barefoot) and kinematic and kinetic outcomes have been published over the last few years. Recent studies however lead to the conclusion that the assumed interactions depend mainly on the subjects' experience of barefoot (BF) walking/running, the preferred running strike pattern, the speed, the hardness of the surface, the thickness of the midsole material, and the runners' level of ability. The aim of the present study was to investigate lower leg kinematics of BF running and running in minimal running shoes (MRS) to assess comparability of BF kinematics in both conditions. To systematically compare both conditions we monitored the influencing variables described above in our measurement setup. We hypothesized that running in MRS does not alter lower leg kinematics compared to BF running.MethodsThirty-seven subjects, injury-free and active in sports, ran BF on an EVA foam runway, and also ran shod wearing Nike Free 3.0 on a tartan indoor track. Lower-leg 3D kinematics was measured to quantify rearfoot and ankle movements. Skin markers were used in both shod and BF running.ResultsAll runners revealed rearfoot strike pattern when running barefoot. Differences between BF and MRS running occurred particularly during the initial stance phase of running, both in the sagittal and the frontal planes. BF running revealed a flatter foot placement, a more plantar flexed ankle joint and less inverted rearfoot at touchdown compared to MRS running.ConclusionBF running does not change the landing automatically to forefoot running, especially after a systematic exclusion of surface and other influencing factors. The Nike Free 3.0 mimics some BF features. Nevertheless, changes in design of the Nike Free should be considered in order to mimic BF movement even more closely.  相似文献   

11.
Abstract

The present experiment investigated the effects of interpolated processing activity (IPA) during the post knowledge of results (KR) interval. The study attempted to correct some of the problems inherent in previous research by using a ballistic timing criterion task and assessing the effects of interpolated processing activity (IPA) on both acquisition and No KR transfer trials. To insure that the efficacy of the IPA manipulation, a paced task was used and performance was assessed. Two levels of post-KR delay (5 and 10 s) were factorially combined with two levels of IPA (IPA or No IPA) to yield four experimental groups. Each subject completed 30 KR acquisition trials and 20 No KR transfer trials. Interresponse interval was held constant. In contrast to many previous studies, IPA interfered with the subjects' ability to learn and perform the criterion movement time of 150 ms. Both the memory trace and the perceptual trace were similarly affected. The detrimental effects of IPA on absolute error and objective-subjective error differences found during acquisition persisted during KR withdrawal.  相似文献   

12.
Abstract

A tennis skill test for use in quantifying achievement in the forehand and backhand drive strokes was developed and then validated using 76 college women enrolled in beginning tennis classes. The test consisted of returning balls pitched by a pneumatic ball machine into target areas drawn in chalk on a regulation tennis court. Speed of the subjects' shots was assessed by measuring accumulated time in flight for rounds of 10 trials using a stopwatch. A time factor was then employed to correct the target value total for the trials to adjust for ball speed, thus rewarding the more skilled player who could stroke the ball more firmly while still retaining control. The test-retest reliability of the test was found to be .84, while the validity of the test, using judges' ratings as a criterion, was .83. It was concluded that the test was a valid and reliable test of skill which was closely related to the actual game situation. Percentile norms were developed on a limited number of subjects.  相似文献   

13.
Abstract

Cinematographic and electromyographic methods were used to coordinate the collection of kinematic and myoelectric data on 41 male subjects. The novel motor task consisted of propelling a four-wheeled carriage along a level aluminum track to a criterion velocity by a knee extension movement. Mean performance scores demonstrated that a significant amount of learning took place over 21 trials. The finding of learning over practice provided a basis by which changes in the kinematic and myoelectric variables were analyzed. Statistical analysis consisted of a One-Sample Hotelling's T2 Test and Trend Analysis using a Multiple Regression Program. Data were collected on trials 1, 2, 6, 15, and 21. Results revealed that: (1) both knee joint and ankle joint angular velocities at release followed the same trend as performance scores; (2) two myotemporal variables had no significant trends on the four muscles under investigation; and (3) two knee flexors had linear trends and two knee extensors had cubic trends on the variable maximum integrated electromyographic (Iemg) amplitude. It was concluded that: (1) trends of joint angular velocities over practice more closely resembled the performance score trends than did myoelectric activity; (2) when myotemporal changes are not evident over practice, changes in maximum Iemg amplitude of muscles are responsible for increasing performance proficiency; and (3) if performance demands an increase in joint angular velocity, agonistic as well as antagonistic myoelectric activity will increase in muscles which act at the joint.  相似文献   

14.
Abstract

Predicated upon the premise that leisure needs are socially determined and therefore dynamic qualities of leisure motivation, this field study investigated the effects of outcome (winning, losing, no outcome) of leisure participation on male and female subjects' leisure needs. Subjects were 438 players of 60 teams in the intramural basketball program comprised of competitive and recreational leagues. Factor analysis produced seven need factors, of which three dealt with interpersonal relationships, two with competence and two with escape or diversion. ANOVAs performed on the resultant factor scores showed that successful and unsuccessful leisure experiences strongly shaped subjects' needs for leisure participation, but these effects were often mediated by the sex of subjects and the competitive levels of leagues in which they played. Generally, winning and losing had just the opposite effects on males' and females' needs; winning increased females' and decreased males' needs. The effects of competitiveness of league types suggested that competitive and recreational leagues serve different psychological functions for males and females because the two leagues are expected to fulfill different leisure needs.  相似文献   

15.
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   

16.
The purpose of the present study was to determine whether playing a specific ball sport, such as tennis, could maintain the coincidence-timing (CT) performance of older adults at a similar level to that of younger ones. To address this question, tennis players and nonplayers of three different age ranges (ages 20-30, 60-70, and 70-80 years) performed a simple CT task consisting of timing their response (pressing a button) to coincide with the arrival of a stimulus at a target. The stimulus moved at either an accelerating, constant, or decelerating velocity. As expected, all participants were affected by the velocity manipulation, which led to late and early responses to accelerating and decelerating stimuli, respectively. Whereas this response bias was increasingly pronounced with advancing age in nonplayers, no difference was found among player groups of different ages. Finally, we showed that the length of the visuomotor delay could explain the effect of nonconstant velocities.  相似文献   

17.
Abstract

Twenty-nine teachers of dance in graduate schools in the United States were interviewed to find out what teachers and what performing artists were seminal in determining their teaching philosophies. Data on the longevity of the teaching careers of the subjects were gathered. A statement of teaching philosophy was sought. The subjects named Gertrude Kline Colby and Margaret Newell H'Doubler as seminal teachers and Martha Graham, Hanya Holm, Doris Humphrey, and Mary Wigman as seminal artists. The longevity of the subjects' careers indicated that they have largely determined the teaching philosophy of dance in education in the United States. The statements of philosophies, although available, are too complex and lengthy for this report.  相似文献   

18.
Purpose

The purposes of this study were to: (a) examine the effect of experience and goal constraints (speed, accuracy) on kicking patterns; (b) determine if effective striking mass was independent of ankle velocity at impact; and (c) determine the accuracy of kicks relative to independent factors.

Method

Twenty participants were recruited to kick at 3 different velocities with and without an accuracy requirement. Multivariate analysis of variance determined if relative timing of joint angular velocities changed during the kick. Chi-square analysis determined if calculated effective mass was independent of ankle velocity at impact. Analysis of variance (ANOVA) was used to examine differences in absolute constant error and variable error according to independent factors.

Results

Results indicated that experience and speed affect absolute timing of joint velocities with no changes in the relative timing of peak joint velocity across independent factors. Chi-square analysis indicated that calculated effective mass is not independent of ankle velocity. ANOVA indicated that experienced performers displayed less variability error than did inexperienced performers.

Conclusion

It was concluded that: (a) Experience, velocity, and accuracy do not affect the relative timing of kicks; (b) kickers trade ankle velocity at impact for greater effective striking mass and ball velocity; and (c) variability in ball placement is affected by experience.  相似文献   

19.
Abstract

Thirty male subjects were given 20 trials of isometric wrist flexion on each arm. Each trial consisted of 5 sec. of maximum exertion followed by a 30 sec. rest period. Subjects were ranked on the basis of the first two trials for each of the limbs and divided into three groups of 10 subjects each representing high, middle, and low levels of strength.

Analysis of variance of the fatigue curve trends suggested that: (a) there is no biologically fixed and constant absolute critical intensity level of isometric muscular tension which occludes intramuscular circulation, and (b) different levels of strength possess dissimilar local circulatory efficiency and/or tolerance to fatigue products.  相似文献   

20.
Abstract

The stated levels of aspirations (L/A's) of high-skilled and low-skilled boys were examined to determine if they differed under prearranged conditions of failure in a simple motor task. Subjects were selected on the basis of their performances on a modified form of the Iowa Brace test. The motor task consisted of moving small blocks from one board to another. Preceding each of three trials, the subjct stated how many blocks he reasonably thought he could move in the succeeding 30-second trial. After a universal performance level was established, failure was induced by systematically stopping the subject before he attained his L/A. A 2×3 factorial design with repeated measures on the second-factor was employed. Analysis of variance indicated that the main effects of skill level and trials were significant at the .05 level. Analysis of simple effects indicated that the L/A's of the high- and low-skilled groups differed significantly only on the third trial (p = .05) and that failure had a significant effect on both groups (p = .10). High-skilled subjects expressed higher L/A's than did low-skilled subjects. All subjects' L/A's lowered significantly over trials. The L/A's of the high-skilled group as compared to the low-skilled group over the three trials did not indicate differential responses.  相似文献   

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