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1.
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   

2.
反应时与动作速度精确度之关系   总被引:10,自引:0,他引:10  
严进洪 《体育科学》2001,21(1):66-68,78
人对自己运动行为控制有3个必须环节:辨认信息,选择反应,及对具体反应动作的程序化。研究影响这3个环节所必须的时间(反应时)的因素,对认识和提高运动动作的速度及准确性有理论和实际意义。本研究结果证明,提高动作的复杂程度(例如在一个动作中增加反复次数)会延长所有年龄组被试的反应时。但动作复杂性对学前儿童及老年人的反应时影响更大。同时,反应的快慢似乎与动作精度的关系大过与动作速度的关系。本文初步探讨了这些数据的神经心理机制,及其对动作教学训练的指导意义。  相似文献   

3.
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   

4.
The purpose of this study was to examine performance differences in arm movement control (programmingvs. "on-line" control) between children with and without attention deficit hyperactivity disorder (ADHD). Twenty children (10 with ADHD and 10 without ADHD) from the ages of 8 to 13 years participated in the study. On the surface of a digitizer, each participant completed three types of aiming arm movements (10 trials for each) and 10 baseline trials (without accuracy requirement). Multivariate analyses of variance with repeated measures were used to analyze the variables of reaction time, movement time, normalized jerk, intersegment-interval (ISI), and movement timing. Children with ADHD appeared to use "on-line " monitoring during the arm movement and did not perform the entire movement sequence as afunctional unit. They executed the arm movements more slowly, had greater variability in movement timing, and demonstrated longer ISIs than their counterparts. Children with ADHD had multiple peaks in the velocity profiles. Children withoutADHD, however, appeared to program their entire arm movements and execute the sequence as a unit. Their velocity profiles were symmetrical with a single peak, and the movement segments were temporally coordinated. Thesefindings suggested that cognitive functions are important resources for controlling rapid aiming arm movements. Children with ADHD might rely more on visual feedback during the movements, which resulted in slower and more variant movement outcomes than children who did not have ADHD.  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

Effects of movement context upon the encoding of kinesthetic spatial location information were examined in a series of experiments using a motor learning paradigm. A cross-modal, kinesthetic to kinesthetic plus visual feedback procedure was used in each experiment to determine the encoding characteristics of spatial information within a variety of movement conditions. Following knowledge of results trials, subjects performing in cross-modal conditions had significant directional errors (overshooting of the target) for spatial locations associated with specific and non-specific body-referents (Experiment 1), for different movement directions to the same target (Experiment 2), and for long (40 cm) movements (Experiments 2, 3) and short (15 cm) movements (Experiment 4). However, subjects in both intermodal and intramodal conditions who switched movement direction had significant undershooting of the spatial targets (Experiment 3). Movement context in terms of response endpoint location or movement length did not have an apparent effect on directional errors. Performances in all experimental conditions were biased in the direction of the movement during learning. The context provided by movement direction did influence the encoding of kinesthetic spatial information.  相似文献   

7.
In the context of strength training in rehabilitation, visual movement control can be helpful to ensure correct movements. However, there are only a few studies that deal with the effectiveness of feedback during resistance exercises. To investigate the effect of feedback during guided exercise, 18 young adults (28.8?±?5.5 years) and 12 senior citizens (67.9?±?4.1 years) were tested. Subjects performed shoulder press exercises (3 sets, 15 repetitions) with and without visual movement control in a randomized order. On day 1, the subjects trained without load, and on day 2 they trained at 50% of their single repetition maximum. Joint articulation at the elbow was recorded using elbow extension and flexion. Autocorrelation was used to determine the reproducibility of movements. Subjects achieved better reproducibility of the movement with feedback than without (χ2?=?19.73; p?<?0.001). There was no effect of the load on motion accuracy (p?>?0.05), but the age group showed a significant effect (χ2?=?6.00; p?=?0.014). The younger group shows a higher degree of movement accuracy. In summary, visual movement control is useful in guided exercises to control movement execution. In clinical setting, this may be a way to control the motion performance of guided strength exercises and to ensure purposeful muscle work. Further studies should clarify the effect of visual feedback on the movement quality in unguided strength exercises.  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.
The objective of this study was to compare the three-dimensional lower extremity running kinematics of young adult runners and elderly runners. Seventeen elderly adults (age 67-73 years) and 17 young adults (age 26-36 years) ran at 3.1 m x s(-1) on a treadmill while the movements of the lower extremity during the stance phase were recorded at 120 Hz using three-dimensional video. The three-dimensional kinematics of the lower limb segments and of the ankle and knee joints were determined, and selected variables were calculated to describe the movement. Our results suggest that elderly runners have a different movement pattern of the lower extremity from that of young adults during the stance phase of running. Compared with the young adults, the elderly runners had a substantial decrease in stride length (1.97 vs. 2.23 m; P = 0.01), an increase in stride frequency (1.58 vs. 1.37 Hz; P = 0.002), less knee flexion/extension range of motion (26 vs. 33 degrees ; P = 0.002), less tibial internal/external rotation range of motion (9 vs. 12 degrees ; P < 0.001), larger external rotation angle of the foot segment (toe-out angle) at the heel strike (-5.8 vs. -1.0 degrees ; P = 0.009), and greater asynchronies between the ankle and knee movements during running. These results may help to explain why elderly individuals could be more susceptible to running-related injuries.  相似文献   

10.
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   

11.
The aim of this study was to examine differences in traditional heart rate variability measurements and heart rate complexity (sample entropy) in young adults grouped by objectively measured achievement of either moderate or both moderate and vigorous physical activity recommendations. Of 168 young adults tested (86 females, 82 males; age 20.5 ± 1.2 years), 119 achieved only recommendations for moderate physical activity (moderate group) and 49 achieved recommendations for both moderate and vigorous physical activity (vigorous group). Analysis of covariance controlling for sex, weekly minutes of moderate physical activity, and percentage of body fat was used to assess between-group differences in heart rate variability and heart rate complexity. Logistic regression analysis was used to determine the group characteristics that best predicted high heart rate complexity and vagal indices of heart rate variability. The majority of the autonomic measures were higher (P < 0.05) in the vigorous group, and regression analysis showed that vigorous physical activity was the only multivariate predictor of higher heart rate complexity and higher heart rate variability. Young adults engaged in regular vigorous physical activity were more than twice as likely to have high heart rate complexity than those involved in predominantly moderate exercise. These findings suggest that vigorous physical activity is more closely associated with high heart rate complexity than moderate physical activity in young adults.  相似文献   

12.
This review summarizes research conducted in our laboratories over the past 5 years aimed at determining the temporal and spatial relationships between eye and hand movements and the amount of central processing that must occur before performing a manual aiming movement, relative to the amount of processing that is done online. All of our research to date points to a two-component model of speed-accuracy control in manual aiming. Several studies have shown that eye and hand movements in manual aiming are inextricably linked both temporally and spatially. Typically, the eye arrives in the vicinity of the target first; this coincides with peak acceleration of the finger during the initial impulse phase of a movement. There is also significant temporal and spatial coupling of the finger, elbow and shoulder in aiming, and movements appear to evolve in a proximal-to-distal fashion. Movements are endpoint driven and variability is reduced with distal approximation to the target. This movement control strategy means that visual information is not only available for use in modifying responses, but there is sufficient time available for its use. In sequential complex aiming movements, the use of visual feedback and on-line processing become even more important. Practice does not diminish the need for on-line processing; rather, its use appears to ensure greater movement efficiency.  相似文献   

13.
This review summarizes research conducted in our laboratories over the past 5 years aimed at determining the temporal and spatial relationships between eye and hand movements and the amount of central processing that must occur before performing a manual aiming movement, relative to the amount of processing that is done online. All of our research to date points to a two-component model of speed-accuracy control in manual aiming. Several studies have shown that eye and hand movements in manual aiming are inextricably linked both temporally and spatially. Typically, the eye arrives in the vicinity of the target first; this coincides with peak acceleration of the finger during the initial impulse phase of a movement. There is also significant temporal and spatial coupling of the finger, elbow and shoulder in aiming, and movements appear to evolve in a proximal-to-distal fashion. Movements are endpoint driven and variability is reduced with distal approximation to the target. This movement control strategy means that visual information is not only available for use in modifying responses, but there is sufficient time available for its use. In sequential complex aiming movements, the use of visual feedback and on-line processing become even more important. Practice does not diminish the need for on-line processing; rather, its use appears to ensure greater movement efficiency.  相似文献   

14.
Abstract

The objective of this study was to compare the three-dimensional lower extremity running kinematics of young adult runners and elderly runners. Seventeen elderly adults (age 67–73 years) and 17 young adults (age 26–36 years) ran at 3.1 m · s?1 on a treadmill while the movements of the lower extremity during the stance phase were recorded at 120 Hz using three-dimensional video. The three-dimensional kinematics of the lower limb segments and of the ankle and knee joints were determined, and selected variables were calculated to describe the movement. Our results suggest that elderly runners have a different movement pattern of the lower extremity from that of young adults during the stance phase of running. Compared with the young adults, the elderly runners had a substantial decrease in stride length (1.97 vs. 2.23 m; P = 0.01), an increase in stride frequency (1.58 vs. 1.37 Hz; P = 0.002), less knee flexion/extension range of motion (26 vs. 33°; P = 0.002), less tibial internal/external rotation range of motion (9 vs. 12°; P < 0.001), larger external rotation angle of the foot segment (toe-out angle) at the heel strike (?5.8 vs. ?1.0°; P = 0.009), and greater asynchronies between the ankle and knee movements during running. These results may help to explain why elderly individuals could be more susceptible to running-related injuries.  相似文献   

15.
Abstract

The aim of this study was to examine differences in traditional heart rate variability measurements and heart rate complexity (sample entropy) in young adults grouped by objectively measured achievement of either moderate or both moderate and vigorous physical activity recommendations. Of 168 young adults tested (86 females, 82 males; age 20.5 ± 1.2 years), 119 achieved only recommendations for moderate physical activity (moderate group) and 49 achieved recommendations for both moderate and vigorous physical activity (vigorous group). Analysis of covariance controlling for sex, weekly minutes of moderate physical activity, and percentage of body fat was used to assess between-group differences in heart rate variability and heart rate complexity. Logistic regression analysis was used to determine the group characteristics that best predicted high heart rate complexity and vagal indices of heart rate variability. The majority of the autonomic measures were higher (P < 0.05) in the vigorous group, and regression analysis showed that vigorous physical activity was the only multivariate predictor of higher heart rate complexity and higher heart rate variability. Young adults engaged in regular vigorous physical activity were more than twice as likely to have high heart rate complexity than those involved in predominantly moderate exercise. These findings suggest that vigorous physical activity is more closely associated with high heart rate complexity than moderate physical activity in young adults.  相似文献   

16.
The purpose of this study was to investigate possible age-related differences in the physical stimulus-psychological response relationship. Young and older adult subjects moved their arm to three standard locations or extents (25 cm, 50 cm, and 75 cm) on a linear positioning device. Seven standard comparison combinations were presented 20 times each. Subjects were asked to determine whether the comparison was different from the standard. Just noticeable difference, constant error, absolute constant error, and Weber ratios were calculated. In contrast to previous studies, the results clearly indicate that the physical stimulus-psychological response magnitude relationship for location and extent movements is best described by a metathetic continuum. We offer an explanation to account for the differences between location and extent movements for the just noticeable difference and Weber ratio. The failure to find differences between the age groups suggests that age-related declines cannot be generalized to all perceptual systems.  相似文献   

17.
Abstract

Lateral movements like cutting are essential in many team sport disciplines. The aim of the present study was to analyse adaptations in motor control in response to task unpredictability during lateral movement execution. Twelve subjects performed lateral jumps with different landing modalities (stable, sliding or counteracting) that were either known (predictable setting) or unknown (unpredictable setting) prior to movement execution. Results revealed that regardless of the landing modality, hip joint abduction was significantly greater in the unpredictable compared to predictable setting. Furthermore, during the sliding landing modality, hip flexion decreased from 211 ± 7° to 207 ± 7° and knee flexion decreased from 26 ± 4° to 24 ± 4° at the instant of ground contact in the unpredictable compared to predictable condition. During the stable landing modality, the knee joint abduction increased from ?0.3 ± 6° to ?3 ± 6° after initial ground contact in the unpredictable compared to predictable setting. The present results support our hypothesis that pre-programmed motor activity depends on the predictability of the landing modality during lateral movements. According to its adaptation in the frontal plane and in some extent in the sagittal plane, the hip joint seems to play the major role in the modulation of the pre-programmed activity for successful lateral jump execution in an unpredictable setting. However, these kinematic adaptations are concerning since these changes were associated with higher knee abduction during the stable landing modality and therefore with possible higher risk of injury.  相似文献   

18.
Reduced feedback during practice has been shown to be detrimental to movement accuracy in children but not in young adults. We hypothesized that the reduced accuracy is attributable to reduced movement parameter learning but not pattern learning in children. A rapid arm movement task that required the acquisition of a motorpattern scaled to specific spatial and temporal parameters was used to investigate the effects of feedback (FB) frequency (100% vs. 62% faded) on motor learning differences between 19 school-age children and 19 young adults. Adults and children practiced the task for 200 trials under the 100% or faded FB condition on day 1 and returned on day 2 for a no-FB retention test. On the retention test, children who practiced with reduced feedback performed with greater temporal parameter errors, but not pattern error than children who received frequent feedback. Motor skill learning in children is influenced byfeedback frequency during practice that affects parameter learning but not pattern learning.  相似文献   

19.
Abstract

When learning verbal information, an important aspect of practice is the method of rehearsal, which has been demonstrated to vary developmentally. A young child practices on an instance-by-instance basis (passive rehearsal), whereas older children and adults practice several items together (active rehearsal). This study investigated the effects of passive and active rehearsal on developmental processing differences for movement reproduction. Three methods of rehearsal were used at ages 5, 7, 11, and 19 years. A child-like strategy forced the subjects to practice location cues for each of eight movements, which were presented one at a time. The mature-strategy group practiced each new position presented with two previously presented positions. A subject-determined strategy group which allowed subjects to choose their own methods of rehearsal was included as a control. Significant ANOVAs supported the hypothesis that quality of rehearsal (active over passive) is important. For the 5- and 7-year-old children, a mature strategy facilitated performance over the child-like strategy, while the use of a child-like strategy hindered the performance when compared to a self-determined or mature strategy. The results of this study indicated the importance of active rehearsal for the younger child.  相似文献   

20.
BackgroundNew research suggests that the composition (mix) of movement behaviors within a 24-h period may have important implications for health across the lifespan. Consistent with this integrated movement behavior paradigm, a number of countries across the world have developed and released 24-h movement guidelines for specific age groups. The purpose of this systematic review was to examine the associations between the 24-h time-use composition of movement behaviors, or adherence to 24-h movement guidelines, and multiple health indicators across the lifespan.MethodsFive online databases (PsycINFO, PubMed, SPORTDiscus, Web of Science, and Ovid MEDLINE) were searched for relevant peer-reviewed studies published between January 2015 and January 2020 that met the a priori inclusion criteria, with no study design limits. The methodological quality of research evidence for each individual study and for each health indicator was assessed by using a modified version of the Downs and Black checklist.ResultsA total of 51 studies from 20 different countries met the inclusion criteria. A total of 31 studies examined adherence (meeting vs. not meeting) to 24-h movement guidelines, and 20 studies used compositional analyses to explore the 24-h time-use composition of movement behaviors. Findings indicated that meeting the 24-h movement guidelines were (1) not associated with adiposity among toddlers, (2) favorably associated with health-related quality of life, social-cognitive development, and behavioral and emotional problems among preschoolers, (3) favorably associated with global cognition, health-related quality of life, and healthy dietary patterns in children, and (4) favorably associated with adiposity, fitness, and cardiometabolic, mental, social, and emotional health among children and youth. Significant associations were also found between the composition of 24-h movement behaviors and indicators of (1) adiposity and bone and skeletal health among preschoolers, (2) health-related quality of life among children, (3) adiposity, fitness, and cardiometabolic, social, and emotional health among children and youth, (4) cardiometabolic health in adults, (5) adiposity and fitness among adults and older adults, and (6) mental health and risk of mortality among older adults. The quality of the available evidence ranged from poor to good.ConclusionThe current evidence indicates that the composition of movement behaviors within a 24-h period may have important implications for health at all ages and that meeting the current 24-h movement guidelines is associated with a number of desirable health indicators in children and youth. Future studies should employ longitudinal and experimental designs, include valid and reliable measures of 24-h movement behaviors, and examine a wide array of health indicators across all age groups. Such studies would confirm the results from the primarily cross-sectional evidence drawn from studies included in our review and further advance our understanding of the relationships between 24-h movement behaviors and health.  相似文献   

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