首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
Abstract

Sixty-six college women enrolled in fencing classes provided measures of reaction time, response time, and movement accuracy on a specially designed apparatus. The subjects then foil-fenced in round-robin tournaments. Criterion measures of fencing achievement derived from tournament matches correlated little better than zero with reaction time, response time, and movement accuracy.  相似文献   

2.
Abstract

The effect of practice on individual differences and intra-individual variability in reaction and movement times were studied for simple and complex, discrete, motor tasks. Changes with practice for intertrial correlations of adjacent trials and the effects of an increasing number of interpolated trials on intertrial correlations were also observed. For both tasks and for both reaction and movement times, the intra-individual variability decreased with practice. The true score variability for reaction time on both tasks and for movement time on the simple task shows little change with practice. On the complex task, true score variability for movement time decreases with practice. For movement time, adjacent trial correlations increase during the early practice trials then remain stable. For reaction time adjacent trial correlations increase throughout practice. Remoteness effects on intertrial correlations were found for both movement and reaction times for both tasks.  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.
Abstract

College men and women were tested as to reaction time and speed of an arm movement using both motor-oriented and stimulus-oriented set. The results confirmed a hypothesis based on neuromotor coordination theory that predicted slower movement and greater reaction latency when the motor set was used. However, the 20 percent of subjects who had a natural motor set tendency moved faster with an enforced motor set than with an enforced sensory set. The conditions of enforced set caused a moderate positive correlation between reaction and movement times. Women subjects reacted and moved slower than men, but were similarly influenced by the two enforced set conditions. Their natural set tendency was definitely stimulus-oriented, while men tended to have a neutral orientation.  相似文献   

5.
Abstract

The theory proposes a nonconscious mechanism that uses stored information (motor memory) to channel existing nervous impulses from brain waves and general afferent stimuli into the appropriate neuromotor coordination centers, subcenters, and efferent nerves, thus causing the desired movement. A consequent hypothesis requires that the simple reaction time will become longer when the response movement is required to be of greater complexity. Data obtained on college men and women, and 12- and 8-year-old boys, are in agreement with the hypothesis. Replacing a very simple finger movement with an arm movement of moderate complexity slows the reaction by about 20 percent; additional complexity produces a further slowing of 7 percent. The speed of the arm movement is considerably faster in college men than in younger boys or in college women. The correlation between reaction time and speed of movement averages approximately zero. Individual differences in ability to make a fast arm movement are about 70 percent specific to the particular movement being made; “general ability for arm speed” occurs only to the extent of 30 percent.  相似文献   

6.
Abstract

The aim of this study was to test the effect that changing targets during a simple long lunge attack in fencing exerts on the temporal parameters of the reaction response, the execution speed, and the precision and the coordination of the movement pattern. Thirty fencers with more than 10 years of experience participated in this study. Two force platforms were used to record the horizontal components of the reaction forces and thereby to determine the beginning of the movement. A three-dimensional (3D) system recorded the spatial positions of the 9 markers situated on the fencer plus the epee, while a moving target was projected on a screen, enabling the control of the target change. The results indicated that when a target change is provoked the reaction time (RT), movement time (MT), and the time used in the acceleration phase of the centre of mass (CM) increases significantly with respect to the attack executed with a straight thrust. The speed and horizontal distance reached by the CM at the end of the acceleration phase (VX(CM) and SX(CM), respectively) significantly decreased, while the errors increased. However, the temporal sequence of the movement pattern did not appreciably change.  相似文献   

7.
Abstract

Several researchers have demonstrated that an external focus of attention (about movement’s effects) during movement execution allowed better performances and learning of various motor tasks than an internal focus of attention (about movement itself). However, attentional focus effects have not been studied in tasks requiring explosive actions preceded by fast reaction time to a signal, such as a sprint start. We hypothesised that the beneficial effect of external focus of attention would be observed in the different stages of the sprint start (i.e. reaction time, block clearance and running) for both expert and novice sprinters. Novice and expert sprinters performed sprint starts followed by a 10 m sprint under three conditions: external focus instructions; internal focus instructions; and neutral instructions. The reaction time and the running time were significantly shorter in the external focus condition than in the internal focus condition, for both expert and novice participants. These results confirm the beneficial effect of an external focus of attention on the speed of movement execution. Moreover, they revealed that attentional focus influences movement preparation. Several hypotheses are proposed to account for these results, with reference to the processes that could be responsible for the observed effects.  相似文献   

8.
Abstract

Two alternative interpretations to the one proposed by Christina, Fischman, Vercruyssen, and Anson (1982) were investigated. They interpreted the simple reaction time (SRT) increase they found, which was thought to reflect an increase in programming time, to be due to the increase in number of movement parts from one response to another. Experiment 1(N = 15 males) tested the alternative interpretation that the SRT increase was caused by the difference in how the first movement part of the three responses was executed. However, no evidence was found to support this interpretation. Experiment 2 (N = 15 males) tested the alternative interpretation that the SRT increase was due to the increase in the demand for movement accuracy from one response to another. The results revealed that only a very small portion of the SRT increase could be attributed to the increased accuracy demand while the major portion of the increase was due to the increase in number of movement parts.  相似文献   

9.
Abstract

This study was concerned with the effect of bench-stepping in the Harvard Step Test upon finger and foot reaction time and, secondarily, with ascertaining the relationship, if any, between these reaction times and scores on the Harvard Step Test. The subjects were university freshman males. Reaction times were taken before, immediately after, and four minutes after the stepping exercise for 80 subjects. Thirty-six subjects served as controls, involving the reaction times and pulse counts at the prescribed intervals but without exercise. The findings failed to divulge any discernible effect of stepping exercise upon reaction time, or any apparent relationship between reaction time and the sum of the recovery pulse counts following the exercise. In view of these findings it is suggested that study be directed to two related aspects — the effect of exercise to exhaustion on reaction time, and the effect of strenuous and exhaustive exercise upon speed of movement.  相似文献   

10.
Abstract

The speed-accuracy operating curve was investigated in a movement precuing two- or four-choice reaction time task. Four levels of response preferences were manipulated with subject instructions and postresponse information: (a) accuracy, (b) reaction time latency, (c) accuracy and reaction time latency, and (d) no preference. Eighty subjects completed 480 discrete keypressing responses with the index and middle fingers of both hands. The mixed design mean reaction time analysis indicated faster performances for the reaction time latency and the accuracy and reaction time latency groups than the no preference group. Additionally, the percent correct analysis revealed two significant interactions: (a) Trial Block x Precue x Response Preference, and (b) Delay x Precue x Hand Position. Overall, the present findings provide partial support for the speed-accuracy operating curve predictions. Caution is advised when drawing chronometric inferences based only on reaction time data or when response accuracies are extremely high.  相似文献   

11.
Abstract

Two experiments were conducted to identify the response elements responsible for the complexity effect found by Henry and Rogers (1960). An attempt was made to determine if these elements were affecting the premotor time component of simple reaction time (SRT). If they were, a strong case could be made for the argument that neuromotor programming time was affected because premotor time is a more exact estimate of it than SRT. The results revealed that premotor time was unaffected by a forward change in movement direction, but increased as the number of movement parts increased from one to two and as the demand for movement accuracy increased. Thus, increasing the (1) number of parts and (2) accuracy demands were identified as elements of response complexity which increase programming time and support Henry and Rogers (1960) hypothesis that the time to initiate a response becomes longer as the programming process become more complex.  相似文献   

12.
ABSTRACT

Fractionated reaction time can be used to determine distinct epochs known as pre-motor, response and movement times (MTs) of a reaction time task. The purpose of this study was to compare elite and novice athletes performing a taekwondo kick in terms of the fractionated reaction time and electromyography (EMG) activation patterns of the muscles of the striking lower limb and the lower back. We hypothesised that the pre-motor time, response time (RT) and MT would be the shorter for elite athletes compared to novices. We collected data on 13 elite and 10 novice athletes when performing a roundhouse kick. The experiment included EMG electrodes placed on five low back and lower extremity muscles and an electrogoniometer placed on the kicking knee. We found that pre-motor time was shorter and the RT was longer for elite athletes than novice athletes. Moreover, the integrated EMG of the main knee extensor does not differ between groups though other leg and trunk muscles do. The results allow coaches and teachers to understand this particular taekwondo kicking movement which could ultimately improve the technique in order to establish training and teaching goals.  相似文献   

13.
Abstract

The aim of the present work is to examine the differences between two groups of fencers with different levels of competition, elite and medium level. The timing parameters of the response reaction have been compared together with the kinetic variables which determine the sequence of segmented participation used during the lunge with a change in target during movement. A total of 30 male sword fencers participated, 13 elite and 17 medium level. Two force platforms recorded the horizontal component of the force and the start of the movement. One system filmed the movement in 3D, recording the spatial positions of 11 markers, while another system projected a mobile target over a screen. For synchronisation, an electronic signal enabled all the systems to be started simultaneously. Among the timing parameters of the reaction response, the choice reaction time (CRT) to the target change during the lunge was measured. The results revealed differences between the groups regarding the flight time, horizontal velocity at the end of the acceleration phase, and the length of the lunge, these being higher for the elite group, as well as other variables related to the temporal sequence of movement. No significant differences have been found in the simple reaction time or in CRT. According to the literature, the CRT appears to improve with sports practice, although this factor did not differentiate the elite from medium-level fencers. The coordination of fencing movements, that is, the right technique, constitutes a factor that differentiates elite fencers from medium-level ones.  相似文献   

14.
Abstract

Subject performed a five-choice reaction time (RT) and movement time (MT) task while walking on a treadmill at heart rates (HR) of approximately 80 (standing still), 115, 145 and 175 beats per minute (bpm). Five-choice RT was optimal at a HR of 115 bpm and worst at 175 bpm, thereby supporting the hypothesis of an inverted U relationship between activation and choice RT. On the other hand, MT improved linearly with increased levels of HR, showing that these two parameters are affected quite differently by concomitant physical exertion.  相似文献   

15.
Abstract

This study seeks to discover whether handball goalkeepers employ a general anticipatory strategy when facing long distance throws and the effect of uncertainty on these strategies. Seven goalkeepers and four throwers took part. We used a force platform to analyse the goalkeeper's movements on the basis of reaction forces and two video cameras synchronised at 500 Hz to film the throw using 3D video techniques. The goalkeepers initiated their movement towards the side of the throw 193 ± 67 ms before the release of the ball and when the uncertainty was reduced the time increased to 349 ± 71 ms. The kinematics analysis of their centre of mass indicated that there was an anticipatory strategy of movement with certain modifications when there was greater uncertainty. All the average scores referring to velocity and lateral movement of the goalkeeper's centre of mass are significantly greater than those recorded for the experimental situation with bigger uncertainty. The methodology used has enabled us to tackle the study of anticipation from an analysis of the movement used by goalkeepers to save the ball.  相似文献   

16.
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   

17.
Purpose: This feasibility study compared the effects of 2 movement programs, traditional and mastery climate (i.e., the Children’s Health Activity Motor Program [CHAMP]), on lesson context and children’s physical activity (PA) levels. A secondary aim was to examine sex differences in PA levels in both programs. Method: Seventy-two preschoolers served as participants and were assigned to a movement program. Physical activity levels and lesson context were assessed with the System for Observing Fitness Instruction Time. Results: Preschoolers in CHAMP spent more time walking (p < .05, = 3.3), more time in moderate-to-vigorous PA (MVPA; p < .05, = 3.6), and less time standing (p < .05, = 3.8) compared with those in a traditional movement program. Boys in both programs spent less time standing (< .05, = 4.8) and more time in vigorous activity (< .05, = 5.8) and MVPA (p < .05, = 4.4) compared with girls. During CHAMP, children spent less time engaged in management and knowledge (< .05, = 1.4, and < .001, = 0.9, respectively) and more time in skill practice (< .05, = 1.5). Conclusion: The findings support that participation in CHAMP elicits more MVPA in preschool-age children compared with a traditional movement program. The Children’s Health Activity Motor Program provided children with more class time devoted to skill practice. The program appears to be an innovative approach that is beneficial for PA engagement and could contribute positively to children’s health.  相似文献   

18.
Abstract

The consistency of separate components of a timing response were measured, and the relationship of these consistencies to the changes in distance, speed, and resistance of the movement were determined. The inconsistency of the total response was less than the sum of the inconsistencies of the response components. Factors which increase the movement time (e.g., greater distance or slower speed) tend to decrease the consistency of both movement time and time of initiation of the response, tending to make the total response more inconsistent. There was a tendency for load to have a stabilizing effect on slower movements and to decrease the consistency of faster movements.  相似文献   

19.
PurposeThe objective of this scoping review was to summarize systematically the available literature investigating the relationships between the coronavirus disease 2019 (COVID-19) pandemic and movement behaviors (physical activity, sedentary behavior, and sleep) of school-aged children (aged 5−11 years) and youth (aged 12−17 years) in the first year of the COVID-19 outbreak.MethodsSearches for published literature were conducted across 6 databases on 2 separate search dates (November 25, 2020, and January 27, 2021). Results were screened and extracted by 2 reviewers (DCP and KR) independently, using Covidence. Basic numeric analysis and content analysis were undertaken to present thematically the findings of included studies according to the associated impact on each movement behavior.ResultsA total of 1486 records were extracted from database searches; of those, 150 met inclusion criteria and were included for analysis. Of 150 articles, 110 were empirical studies examining physical activity (n = 77), sedentary behavior/screen time (n = 58), and sleep (n = 55). Results consistently reported declines in physical-activity time, increases in screen time and total sedentary behavior, shifts to later bed and wake times, and increases in sleep duration. The reported impacts on movement behaviors were greater for youth than for children.ConclusionThe COVID-19 pandemic is related to changes in the quantity and nature of physical activity, sedentary behavior, and sleep among children and youth. There is an urgent need for policy makers, practitioners, and researchers to develop solutions for attenuating adverse changes in physical activity and screen time among children and youth.  相似文献   

20.
Reaction time, fractionated reaction time (premotor and motor time), and movement time were recorded during performance of a rapid aiming movement (11 mm in amplitude) to a circular target. Independent variables were target diameter (2 or 64 mm) and reaction time condition (simple or choice). Fifty-two subjects performed 16 practice and 24 performance trials under one of four possible experimental combinations (13 subjects per combination) in a 2 × 2 design. Reaction time correlated highly with premotor time (r = .99) but not with motor time (r = .31). Choice reaction time and its premotor time component were dependent upon target diameter, but simple reaction time and its premotor time component were not. However, choice and simple motor time were not differentially affected by target diameter. As expected, movement time was longer for the small target than for the large target. Taken together, the reaction time results were interpreted as support for Klapp's (1975) hypothesis that increases in choice reaction time for rapid movements to a small target are due to increases in the time needed for programing the response.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号