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1.
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   

2.
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   

3.
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   

4.
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   

5.
Abstract

Motor pool excitability, H-reflex amplitude, was studied in RT responses preceded by varied foreperiods. Rapid plantar flexion of the foot followed auditory warning signals, varied foreperiods, and visual RT stimuli. Response speed was latency of EMG onset in the soleus muscle (PMT). The H-reflex stimulus was either omitted (none), or presented at one of three intervals in the movement response period: 0 (simultaneous with RT stimulus), 100 or 200 ms following stimulus. Control H-reflexes were taken before and after RT trials. The motor pool was not differentially excited following the random foreperiods. In fact it was not elevated over control values until late into the preparatory period (200 ms) which probably reflects the direct expression of the motor command. Using the H-reflex paradigm in combination with a RT response strongly altered the PMT when the H-reflex was presented early in the preparatory period (0). Since motor pool excitability changes were not evident early in the movement preparation period, they poorly predicted PMTs.  相似文献   

6.
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   

7.
Abstract

This study investigated stimulus velocity effect on manual asymmetry during planning and execution of a complex coincidence-anticipation task. Left- and right-handers were required to press six buttons sequentially in conjunction with visual stimulus provided by a coincidence-anticipation device. Results showed that (1) stimulus velocity affected timing response and timing accuracy only for right-handers, who responded faster but less accurately in the fast stimulus velocity, (2) manual asymmetries for both handedness groups revealed a left-hand advantage for initiating the movement, and a preferred-hand advantage for movement time. The preferred-hand advantage in timing accuracy was only observed in the fast stimulus velocity. These findings are discussed in the framework of the hemispheric functional lateralisation.  相似文献   

8.
Abstract

The field of movement behavior has been strongly led by a research tradition in which manipulations are performed in order to search for differences in dependent variables. In this article, I argue for an alternative viewpoint, in which experimental manipulations are provided so that invariances in dependent variables can be seen. If, in the face of changes in nearly countless dependent variables, a particular simple or derived value remains constant, strong suggestions are provided about the underlying control of the motor system. This method is illustrated with examples of invariances in motor behavior, the most important of which is the tendency for the temporal events in a movement to expand or contract nearly proportionally with movement time so that relative timing is invariant. A model following from these invariances, and criticisms of it, are discussed.  相似文献   

9.
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   

10.
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   

11.
Abstract

The net speed of arm movement made in response to sounds of 45, 65 and 85 db. loudness was measured by chronoscope. Reaction time was excluded. Thirty-six college men were tested. In another experiment, the force of successive contractions of the forearm muscles in response to serial auditory stimuli spaced 5 sec. apart was measured by a recording dynamometer. In both experiments there was a balanced order of presenting the three stimulus intensities. In general, the louder sounds produced faster arm movements and stronger contractions of the muscles. In explanation, it is postulated that greater perceived stimulus intensity results in stronger excitation of the pyramidal tracts and consequently more forceful muscular contractions.  相似文献   

12.
Abstract

This study investigated the time needed to change a motor program that specified the elbow flexor muscles to gradually increase the isometric force production from 15% to 75% of one's maximum voluntary contraction (MVC). A double-stimulation paradigm was used with the restriction that subjects (N = 12) be at 15% of their MVC before the presentation of the first stimulus. Subjects reacted to the first stimulus (randomly presented) by gradually increasing their isometric force from 15% to 75% of their MVC and then reacted to the second stimulus by altering the force production in one of four ways: (a) increasing the force to the 75% level rapidly instead of gradually, (b) discontinuing the increase and maintaining the level of force attained, (c) discontinuing all force production, or (d) reversing the direction of force so that it is produced by the elbow extensors. The data revealed that more time was needed to increase the force rapidly than to perform any of the other three conditions.  相似文献   

13.
Abstract

Twenty-four male subjects were used to study effects upon successive hand reaction times when the interval between paired visual stimuli was manipulated over the range 50 to 1,000 mseconds. Subjects were divided into fast and slow groups on the basis of well-practiced simple reaction time measures. Results indicated that both simple reaction time and initial paired response reaction time were unrelated to delays in the second response due to the psychological refractory period. It was suggested that a serious reappraisal of the single channel response system theory merits consideration and that ability to execute fast, consecutive paired responses may represent a new component in motor skills.  相似文献   

14.
Abstract

The present study sought to determine whether individuals could be trained to attenuate the visual dominance effect by selecting a proprioceptive stimulus for attention. Using a reaction time (RT) task, subjects received either: (a) visual (V), (b) proprioceptive (P), or (c) combined V and P (VP) stimuli during the first four days. Each subject was then tested under all three stimuli conditions. Results showed that reaction time to the P cue was always faster than that to V or combined VP stimuli. The order in which subjects were tested under each stimulus modality significantly affected the results such that those subjects who received initial exposure to the V stimulus produced the slowest premotor time scores but the fastest motor time scores. These results suggest that the nature of the stimulus which initiates the volitional task can affect both the central processing requirements to initiate the response, and the qualitative manner in which the motor command is executed.  相似文献   

15.
Abstract

This study was designed to determine whether there was a difference in the effectiveness of the traditional method and the movement exploration method of teaching physical education activities to elementary school girls. Four classes of fourth-grade girls (N = 67) were randomly assigned to the experimental conditions. A 2 × 2 × 3 factorial ANOVA with repeated measures on the last factor was used to analyze the data. The first factor consisted of the traditional and movement exploration teaching methods. The second was a combination of instructional time and retention time. The third was test period and had three levels: pretest, posttest, and retention test. Skills taught were gymnastics and tumbling, and basketball. It was concluded that a combination of methods should be used in teaching elementary school physical education activities, depending upon the activities to be taught. A four-week unit (two 50-min periods per week) is suggested as the appropriate length for nine and ten year olds.  相似文献   

16.
Research investigating the preparation and control of rapid, multisegmented responses typically has assumed complete programming of the response occurring prior to movement initiation and has made use of a simple reaction time (RT) paradigm. A notable exception is Rosenbaum's work which proposed the Hierarchical Editor (HED) model that is specifically directed toward the control of movements in the choice environment. The purposes of this study were to investigate the assumption of complete programming prior to movement initiation and to compare predictions of the HED model with other programming models. Three experiments are reported in which subjects were required to tap either one, two, or three plates as rapidly as possible in either a simple or choice RT situation. The results were very consistent in these experiments even with several modifications in apparatus and methodology. Of particular interest were effects of movement complexity on RT and movement time (MT) for the first and second segments of the movement (M1 and M2). Choice RT (CRT) results consistently showed no increases in RT as the number of movement segments increased but showed significant increases in M1. For simple RT situations, however, there were small but consistent increases in RT as well as increases in M1 with increases in the number of movement parts. For both CRT and SRT results, small but nonsignificant increases were noted for M2. These results provide evidence for incomplete programming prior to response initiation. Although the SRT data can be accommodated by Henry's theory, the HED model appears to offer the best overall fit for the results.  相似文献   

17.
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   

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.
Abstract

The purpose of this study was to compare reaction time (RT) and fractionated RT components (premotor and motor times) between normal and postcontraction conditions. Twelve participants performed 20 trials each of control and postcontraction RT conditions. For the control condition, participants executed a learned, rapid, knee-extension contraction response to an auditory stimulus. The postcontraction condition was identical to the control condition except that the participants performed a 3-s isometric contraction of the knee extensor muscles prior to an auditory stimulus. Muscle activity was recorded from the quadriceps muscle group. Results indicated that the postcontraction condition was significantly faster than the control condition for the average RT, premotor time, and motor time. It was concluded that reaction time, processing time, and muscle contraction time for a learned task could be significantly reduced following an isometric contraction.  相似文献   

20.
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   

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