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 531 毫秒
1.
This research examined varying levels of physical activity and psychomotor and physiological function in variously active older men. Very active moderately active, and low active participants were tested on simple (SRT) and choice reaction time (CRT), coincidence-anticipation timing (CAT), and VO2max. No significant differences for age or height were found, although percentage of fat, and weight were statistically different. Active groups were leaner and lighter. VO2max was significantly different between groups, as physically active groups yielded geater values. SRT and CAT also yielded significantly different results with more active participants showing better performance. No between-groups significant differences resulted for CRT. Generally, increased levels of physical activity were related to superior physiological outcomes and improved psychomotor peformance.  相似文献   

2.
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   

3.
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   

4.
Age-related differences in response programming   总被引:1,自引:0,他引:1  
Age-related differential effects on reaction time (RT) performance for movement complexity and response-response (R-R) compatibility were examined in children, adolescents, and young adults. A two-choice RT paradigm involved three different finger responses, and each finger movement response was paired with every other movement response. Movement complexity was manipulated by varying the digits activated and was measured as the mean RT for a particular movement across all choice pairs. R-R compatibility was manipulated by altering the pairing of choice alternatives and was determined by the mean RT comparison for each of the movements according to the paired choice alternative. Simple RTs were also obtained for all finger movement responses for comparison with the RTs achieved in choice situations. Age-related differences were found for both movement complexity and R-R compatibility. Mean RT and response consistency improved with age. Although higher overall speeds were found with age, adolescents were not significantly slower than young adults. Adolescents did, however, make significantly fewer response errors on movements differing in complexity. Bilateral versus unilateral control and number of fingers involved in the task were found to affect both movement complexity and the compatibility between response pairs. The relationship between the alternative and choice response was found to be a robust factor affecting R-R compatibility. Choice responses were significantly slower than simple responses, and the rank ordering of movement responses was identical within the two paradigms.  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.
This study evaluated the effects of a three-year exercise program on motor performance and cognitive processing speed of previously sedentary older women, ages 57-85. Variables tested were simple and choice reaction time (CRT), balance, sit and reach flexibility, shoulder flexibility, and grip strength. Subjects participated three times a week in exercise performance classes designed to meet American College of Sports Medicine guidelines. Results indicate that performance was significantly improved on all measures during the course of the study (p less than .01) except for the sit and reach test (SRT), where significance was approached (p less than .027), but not reached. A comparison of the exercise subjects with a comparable group of nonexercising control subjects revealed significant interactions between treatment and time on all variables except CRT and grip strength. Pretest to posttest scores of the exercise subjects tended to improve over the three-year period, whereas the scores of the control subjects declined. Improved reaction time indicated exercise is effective in reversing or at least slowing ceratin age-related declines in motor performance and in speed of cognitive processing.  相似文献   

7.
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   

8.
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   

9.
Abstract

This study evaluated the effects of a three-year exercise program on motor performance and cognitive processing speed of previously sedentary older women, ages 57–85. Variables tested were simple and choice reaction time (CRT), balance, sit and reach flexibility, shoulder flexibility, and grip strength. Subjects participated three times a week in exercise performance classes designed to meet American College of Sports Medicine guidelines. Results indicate that performance was significantly improved on all measures during the course of the study (p < .01) except for the sit and reach test (SRT), where significance was approached (p < .027), but not reached. A comparison of the exercise subjects with a comparable group of nonexercising control subjects revealed significant interactions between treatment and time on all variables except CRT and grip strength. Pretest to posttest scores of the exercise subjects tended to improve over the three-year period, whereas the scores of the control subjects declined. Improved reaction time indicated exercise is effective in reversing or at least slowing certain age-related declines in motor performance and in speed of cognitive processing.  相似文献   

10.
Abstract

It is well documented that simple reaction time (RT) varies inversely with stimulus intensity, but there is disagreement as to which stimulus modality produces the fastest simple RT. An investigation was conducted to equate two stimulus modalities, auditory (A) and electrocutaneous (EC), using varying stimulus intensities in a simple RT protocol. A second investigation was then conducted to examine neuromotor characteristics of stimulus-evoked responses using previously equated A and EC stimuli of varying intensity from the first investigation. Results showed that RT, premotor time (PMT), and motor time (MT) were all inversely related to stimulus intensity, while maximum displacement (MAXD) was directly related to stimulus intensity, and movement time was not affected by stimulus intensity. We conclude that: (a) both central and peripheral components of RT are altered by varying stimulus intensities, and (b) rapid movements are enhanced by increasing stimulus intensity.  相似文献   

11.
Individuals practiced two unique discrete sequence production tasks that differed in their relative time profile in either a blocked or random practice schedule. Each participant was subsequently administered a "precuing" protocol to examine the cost of initially compiling or modifying the plan for an upcoming movement's relative timing. The findings indicated that, in general, random practice facilitated the programming of the required movement timing, and this was accomplished while exhibiting greater accuracy in movement production. Participants exposed to random practice exhibited the greatest motor programming benefit, when a modification to an already prepared movement timing profile was required. When movement timing was only partially constructed prior to the imperative signal, the individuals who were trained in blocked and random practice formats accrued a similar cost to complete the programming process. These data provide additional support for the recent claim of Immink & Wright (2001) that at least some of the benefit from experience in a random as opposed to blocked training context can be localized to superior development and implementation of the motor programming process before executing the movement.  相似文献   

12.
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   

13.
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   

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

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   

16.
Abstract

The experiment was designed to (a) examine age-related differences in the control of aiming movements, and (b) determine the locus of slowing in movement execution of older adults. Fitts's (1954) index of difficulty (ID) was used to manipulate movement execution demands, and kinematics were used to examine the response characteristics. Twelve young and 12 older adults performed simple aiming movements 10 cm or 20 cm in amplitude to targets of 0.5 cm, 1.0 cm, or 2.0 cm in width, resulting in IDs ranging from 3.32 to 6.32. The results for both young and older subjects support the prediction that movement time (MT) increases as a function of ID and that older adults are significantly slower and more affected by increases in ID than the young adults. Velocity and acceleration profiles of the older adults' movements displayed very different response characteristics than those of the young adults. The results suggest that older adults emphasize accuracy of response and are concerned with the latter phase of the movement in order to contact a target accurately.  相似文献   

17.
The objectives of this study were to investigate the effect that the presence of two stimuli that require two different responses (dual-attention) has both, on offensive reaction-response time to a light stimulus, and on defensive response time when the stimulus is a real fencing attack. Twenty-five elite fencers and a fencing master were included in the study. The equipment included four force plates adapted to a scaffold that served as a fencing piste. Two force plates were placed, at the start position, under the fencer’s feet and another two plates were placed under the master’s feet. The results demonstrate that choice reaction time to visual stimuli increases in dual-task conditions with respect to simple reaction time, whereas the mean horizontal force tends to decrease in dual-task. However, when the stimulus was an opponent’s movement, dual-task conditions did not have any effect on the time required to initiate a defensive action. The changes in reaction time when real movements were used as stimuli challenge the validity of the reaction time to visual stimuli paradigm as a predictor of performance in fencing. Also, the results obtained demonstrate that perceptual and attentional processes play a major role in fencer performance in real competition.  相似文献   

18.
The purpose of this study was to determine how the manipulation of movement duration affects components of fractionated reaction time and presumably motor programming. Twelve subjects, in a simple reaction time paradigm, responded to an auditory signal by executing an elbow flexion movement in the sagittal plane through a range of motion of 100° in 150, 300, 600 and 1200 ms. Results indicated no changes in motor time but small increments in premotor and reaction time through the 600 ms condition. At 1200 ms, reaction time increased faster than premotor time, and this appeared to be predominantly a consequence of an increment in motor time. These data were interpreted to be supportive of the notion that movement duration is related to response complexity and the time required for motor programming.  相似文献   

19.
This study biomechanically quantified the movement patterns for six elite goalkeepers making diving saves to their preferred and non-preferred side at three different dive heights. Synchronised three-dimensional kinematic and kinetic biomechanical data analysis found diving direction to significantly (P < 0.05) influence the movement patterns of the diving save. The non-preferred side displayed greater lateral rotation of the pelvis and thorax at the initiation event. These over-rotational differences were reduced during the time on plate phase with the thorax displaying no significant difference at take-off; although a difference still remained for the pelvis. These over rotations were subsequently linked to greater peak knee joint moments, lower peak ankle joint moments, less hip extension at take-off, and for the centre of mass (COM) to travel slower and less directly to the ball, as measured by the net projection angle at take-off. These results indicate that joint movements in the transverse plane at or before the initiation event for the dive for the pelvis and thorax are the causation for subsequent asymmetries. These observed differences indicate that there is an advantage in having prior knowledge of limb preference in an opposing goalkeeper.  相似文献   

20.
We tested the hypothesis that quiet eye the final fixation before the initiation of a movement in aiming tasks, is used to scale the movement's parameters. Two groups of 12 participants (N=24) threw darts to targets in the horizontal and vertical axes under conditions of higher (random) or lower (blocked) target variability. Supporting our predictions, random practice and target changes in the vertical axis led to longer quiet eye duration than did blocked practice and target changes in the horizontal axis. Our data suggest that quiet eye is not simply a mediating factor in accuracy, but is responsive to the task's programming demands, being influenced by the necessity to reparameterize the movement from one trial to the next.  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