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1.
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   

2.
The time course of movement timing reprogramming was examined in a task requiring temporal coincidence of the conclusion of a forehand drive with the arrival of a moving luminous target at the end of an electronic trackway. The moving target departed from one end of the trackway at a constant velocity of 2?m . s?1, and for a part of the trials its velocity was increased to 3?m . s?1. Target velocity was modified at different moments during stimulus displacement, producing times-to-arrival after velocity increment (TAVIs) from 100 to 600?ms. The effect of specific practice on movement reprogramming was also examined. The results showed early adjustments to the action (TAVIs = 100?–?200?ms) that seemed to be stereotyped, while feedback-based corrections were implemented only at TAVIs of 300?ms or longer. Temporal accuracy was progressively increased as longer TAVIs were provided up to 600?ms. Skill training led to an overall increment of temporal accuracy, but no effect of specific practice was found. The results indicate that timing reprogramming in interceptive actions is a continuous process limited mainly by intrinsic factors: latency to initiate more effective adjustments to the action, and rate-of-movement timing reprogramming.  相似文献   

3.
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   

4.
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   

5.
The purpose of the present study was to evaluate the quality of a motor response for different levels of expectancy and time constraint, in a two-choice coincidence-anticipation task. The probability of each of the two events likely to be presented were varied across different levels as well as the speed of the stimulus to be intercepted. The results indicated that neither the choice reaction time (CRT) and movement time, nor the performance of coincidence-anticipation were affected by the probability of the stimulus for the low and moderate stimulus speeds. However, when the stimulus traveled at a high speed a trade-off took place. The CRT decreased as the probability of the event increased, whilst the proportion of response initiation errors increased for the low probability events. This trade-off resulted in a better coincidence-anticipation as the probability of the event increased. The results obtained in the present experiment are clearly different from those obtained in a classic CRT-deadline paradigm, in that the trade-off observed between CRT and response initiation errors was far less pronounced in the coincidence-anticipation task. This difference was attributed to the higher negative consequences associated with a response initiation error in a coincidence-anticipation task. It is thus concluded that the tasks used to study the nature of the decision processes taking place in sports and sports-like situations must have some ecological validity to be of some help for the practitioner.  相似文献   

6.
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   

7.
The time course of movement timing reprogramming was examined in a task requiring temporal coincidence of the conclusion of a forehand drive with the arrival of a moving luminous target at the end of an electronic trackway. The moving target departed from one end of the trackway at a constant velocity of 2 m (.) s(-1), and for a part of the trials its velocity was increased to 3 m (.) s(-1). Target velocity was modified at different moments during stimulus displacement, producing times-to-arrival after velocity increment (TAVIs) from 100 to 600 ms. The effect of specific practice on movement reprogramming was also examined. The results showed early adjustments to the action (TAVIs = 100 - 200 ms) that seemed to be stereotyped, while feedback-based corrections were implemented only at TAVIs of 300 ms or longer. Temporal accuracy was progressively increased as longer TAVIs were provided up to 600 ms. Skill training led to an overall increment of temporal accuracy, but no effect of specific practice was found. The results indicate that timing reprogramming in interceptive actions is a continuous process limited mainly by intrinsic factors: latency to initiate more effective adjustments to the action, and rate-of-movement timing reprogramming.  相似文献   

8.
Abstract

We previously estimated the timing when ball game defenders detect relevant information through visual input for reacting to an attacker's running direction after a cutting manoeuvre, called cue timing. The purpose of this study was to investigate what specific information is relevant for defenders, and how defenders process this information to decide on their opponents' running direction. In this study, we hypothesised that defenders extract information regarding the position and velocity of the attackers' centre of mass (CoM) and the contact foot. We used a model which simulates the future trajectory of the opponent's CoM based upon an inverted pendulum movement. The hypothesis was tested by comparing observed defender's cue timing, model-estimated cue timing using the inverted pendulum model (IPM cue timing) and cue timing using only the current CoM position (CoM cue timing). The IPM cue timing was defined as the time when the simulated pendulum falls leftward or rightward given the initial values for position and velocity of the CoM and the contact foot at the time. The model-estimated IPM cue timing and the empirically observed defender's cue timing were comparable in median value and were significantly correlated, whereas the CoM cue timing was significantly more delayed than the IPM and the defender's cue timings. Based on these results, we discuss the possibility that defenders may be able to anticipate the future direction of an attacker by forwardly simulating inverted pendulum movement.  相似文献   

9.
Abstract

Left-handed performers seem to enjoy an advantage in interactive sports. Researchers suggest this is predominantly due to the relative scarcity of left-handers compared with right-handers. Such negative frequency-dependent advantages are likely to appear in inefficient game-play behaviour against left-handed opponents such as reduced ability to correctly anticipate left-handers' action intentions. We used a pre–post retention design to test whether such negative frequency-dependent perceptual effects can be reversed via effective training. In a video-based test, 30 handball novices anticipated the shot outcome of temporally occluded handball penalties thrown by right- and left-handed players. Between the pre- and post-tests, participants underwent a perceptual training programme to improve prediction accuracy, followed by an unfilled retention test one week later. Participants were divided into two hand-specific training groups (i.e. only right- or left-handed shots were presented during training) and a mixed group (i.e. both right- and left-handed shots were presented). Our results support the negative frequency-dependent advantage hypothesis, as hand-specific perceptual training led to side-specific improvement of anticipation skills. Similarly, findings provide experimental evidence to support the contention that negatively frequency-dependent selection mechanisms contributed to the maintenance of the handedness polymorphism.  相似文献   

10.
Abstract

This study contrasted prepractice modeling with either the perceptual component (perceptual modeling) or the motor component (movement pattern) of a coincident-timing task to determine whether experiencing the modalities singly or in combination enhanced timing performance on initiation of active practice. The motor component was a 60-cm right-to-left arm movement coincident with the illumination of lights on a Bassin timer runway to displace a barrier as the final runway light was illuminated. Four groups were compared (n = 12 per group). A perceptual modeling group passively viewed stimulus runway lights prior to attempting the task. A motoric modeling group viewed a videotape prior to practice of a model performing the motor component of the skill with zero timing error. A perceptual modeling plus motoric modeling group experienced both modeling modalities prior to performance. Finally, a no modeling group simply initiated practice on the task without modeling. Results indicated that the groups experiencing perceptual modeling initiated practice with significantly less average timing error and variability. Thus, perceptual modeling appeared to be at least as important as motoric modeling as a source of prepractice information to make available to a learner to optimize coincident-timing skill acquisition.  相似文献   

11.
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   

12.
The aim of this study was to analyse the effect of stimulus change timing on reaction response time parameters, horizontal velocity of the centre of mass (CM) and precision during offensive actions in fencing. Twelve fencers from the Spanish National Foil Team were included in the study. Two 500 Hz force plates were used to register the horizontal component of the reaction force while a 3D video camera set at 250 Hz recorded the spatial position of 11 body markers and a projector connected to a programmed stopwatch projected a moving target (stimulus) on a screen. When the circle (target) appeared in the centre of the plastron, fencers had to execute a step-forward-lunge as fast as possible, trying to touch the circle with the tip of the foil. During the lunge, the position of the target could randomly shift or not to three different positions. The stimulus change was performed randomly at four different times with a progressive delay. The results show that target changes did not have any effect when they occurred at the beginning of the movement sequence. However, when the target change was delayed, reaction and movement times increased and the technical execution of the lunge changed, leading to more errors.  相似文献   

13.
Abstract

Release velocity and accuracy are vital components of throwing performance. However, there is no published research on these parameters for throwing in cricket. In this study, we investigated the throwing performance of 110 cricket players from six different populations: elite senior males, elite under-19 junior males, elite under-17 junior males, elite senior females, elite under-19 junior females, and sub-elite senior males. Based on a specifically designed cricket throwing test, participants were assessed for (1) maximal throwing velocity and (2) throwing accuracy at maximal velocity and at three sub-maximal velocities. Elite senior males exhibited the highest peak and mean maximal throwing velocities (P≤0.001). Furthermore, the groups of males had significantly higher peak and mean maximal throwing velocities than the groups of females (P≤0.01). A speed–accuracy trade-off existed such that all groups demonstrated improved accuracy scores at velocities between 75% and 85% maximal throwing velocity compared with 50% maximal throwing velocity and 100% perceived maximal exertion. The results indicate that sex, training experience (years training), and training volume (training time per week) may contribute to throwing performance in cricket players. Further research should focus on understanding the mechanisms behind the observed differences between these groups. This is the first study to describe the inherent throwing profiles of different cricket playing populations. Potentially, we have identified stimulus material for future training developments.  相似文献   

14.
Abstract

Research examining the proximal-to-distal sequencing of segments of the body involved in overarm throwing has been equivocal: some studies have found support for the concept while others have not. The aim of the present study, therefore, was to determine if there is a proximal-to-distal sequence in the timing of the movements of joints and the distal endpoints of segments in overarm throwing. The three-dimensional kinematics of a penalty throw in experienced team handball players (n = 11) were recorded and analysed with regard to the timing of events. We analysed the timing of the maximal velocity of the distal endpoints of six segments and the maximal angular velocity in 11 joints, as well as the initiation of these joint movements. A temporal proximal-to-distal sequence was observed only for the initiation of the joint movements. No such sequence was found for maximal velocity of the joints and distal endpoints of segments.  相似文献   

15.
The present study aimed to clarify the effects of oncoming target velocities on the ability of rapid force production and accuracy and variability of simultaneous control of both force production intensity and timing. Twenty male participants (age: 21.0 ± 1.4 years) performed rapid gripping with a handgrip dynamometer to coincide with the arrival of an oncoming target by using a horizontal electronic trackway. The oncoming target velocities were 4, 8, and 12 m · s?1, which were randomly produced. The grip force required was 30% of the maximal voluntary contraction. Although the peak force (Pf) and rate of force development (RFD) increased with increasing target velocity, the value of the RFD to Pf ratio was constant across the 3 target velocities. The accuracy of both force production intensity and timing decreased at higher target velocities. Moreover, the intrapersonal variability in temporal parameters was lower in the fast target velocity condition, but constant variability in 3 target velocities was observed in force intensity parameters. These results suggest that oncoming target velocity does not intrinsically affect the ability for rapid force production. However, the oncoming target velocity affects accuracy and variability of force production intensity and timing during rapid force production.  相似文献   

16.
Background:Proprioceptive accuracy refers to the individual’ s ability to perceive proprioceptive information,that is,the information referring to the actual state of the locomotor system,which originates from mechanoreceptors located in various parts of the locomotor system and from tactile receptors located in the skin.Proprioceptive accuracy appears to be an important aspect in the evaluation of sensorimotor functioning;however,no widely accepted standard assessment exists.In this systematic ...  相似文献   

17.
Abstract

Two experiments examined the reproduction accuracy and retention characteristics of two-dimensional movement information. Distance, location, and combined location plus distance groups were examined under three retention intervals. The results of both experiments generally revealed that distance cues were maintained over a 15-second rest interval and subject to decay when interpolated activity was introduced. In contrast, recall accuracy for both the location group and the location plus distance group decayed during the rest interval. Following the presentation of interpolated activity, the location group exhibited no further decrement while the location plus distance group continued to demonstrate a decay in accuracy. These results imply a differential access to central processing for the two sources of movement information. That is, contrary to the results of previous studies utilizing one-dimensional tasks, two-dimensional distance cues appear to be centrally processed while location cues are not. Thus, when distance and location information is available, only the distance information appears to have access to central processing. Apparently, distance cues are more readily rehearsable in a two-dimensional task. It might be argued that distance information, with such additional cues as movement rate, timing, etc., is more appropriate for two-dimensional tasks while location information is relied on in one-dimensional tasks.  相似文献   

18.
Abstract

The aim of the study was to explore the significance of the ‘timing’ of the quiet eye (QE), and the relative importance of late (online control) or early (pre-programming) visual information for accuracy. Twenty-seven skilled golfers completed a putting task using an occlusion paradigm with three conditions: early (prior to backswing), late (during putter stroke), and no (control) occlusion of vision. Performance, QE, and kinematic variables relating to the swing were measured. Results revealed that providing only early visual information (occluding late visual information) had a significant detrimental effect on performance and kinematic measures, compared to the control condition (no occlusion), despite QE durations being maintained. Conversely, providing only late visual information (occluding early visual information) was not significantly detrimental to performance or kinematics, with results similar to those in the control condition. These findings imply that the visual information extracted during movement execution – the late proportion of the QE – is critical when golf putting. The results challenge the predominant view that the QE serves only a pre-programming function. We propose that the different proportions of the QE (before and during movement) may serve different functions in supporting accuracy in golf putting.  相似文献   

19.
Abstract

When the response movements are as short and simple as possible, the time lag between stimulus and response for one movement is shortened by introducing the stimulus for a second movement during the latent period for the first (usually about .22 sec). Under these conditions the latent period of the second movement is increased about 25 percent. This does not seem to be caused by true psychological refractoriness, since ability to accept the second stimulus and respond to it is still present. A control experiment furnishes evidence that it is probably a foreperiod-expectancy phenomenon. The length of the response latency of a simple single movement is increased about 40 percent if conditions are altered so that a second stimulus requiring a second movement is expected some time within a half-second after the first stimulus. All of these results are consistent with the recent memory drum theory of neuromotor response.  相似文献   

20.
Abstract

Age group differences in the direction of anticipatory motor responses may be attributable to the increased susceptibility of young children to contextual factors. That is, their performances on a given trial may be influenced by the stimulus speed presented in the previous trial. Mixed-sex groups of 8–9 year-olds and adults were given 3 blocks of 18 coincidence-anticipation trials each in a counterbalanced design. One block contained stimulus speeds of 1, 3, or 5 MPH, another speeds of 3, 5, or 7 MPH, and a third speeds of 5, 7, or 9 MPH, so that the 5 MPH speed was common to all blocks. An age group by sex by testing order by trial block ANOVA of constant error on the 5 MPH trials indicated that trial block was a significant factor within an age group by block interaction. Mean scores showed that the children responded very early in the 5–7–9 MPH block to the 5 MPH stimuli while the adults did not. Testing order was also a significant factor: subjects in the 1–3–5, 5–7–9, 3–5–7 MPH order performed with significantly greater directional error. While the later finding may indicate contextual factors influenced performance, there is no strong evidence that contextual factors differentially affected the age groups.  相似文献   

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