干扰情境下类比习得运动技能的稳定性表现

本实验以高尔夫推杆技能学习为任务,采用双因素混合设计,通过对24名高尔夫新手的研究比较了类比和外显两种学习方式获得的运动技能在干扰情境下的操作表现。结果发现:(1)类比学习和外显学习在运动技能形成过程中的效果是相当的;(2)类比学习获得的运动技能在干扰情境下操作表现稳定,而外显学习获得的运动技能表现却下降。类比学习是一种具有实践应用价值的内隐学习方法。     

The Effects of Attentional Focus Instructions and Task Difficulty in a Paced Fine Motor Skill

Abstract

An external focus of attention is considered superior to an internal focus for learning and performance. However, findings specific to changing the task difficulty are inconsistent. The present study used a reciprocal aiming task to determine the effects of attentional focus on motor performance using speed-accuracy paradigm. We constrained timing to examine how internal and external focus of attention influenced accuracy when task difficulty changes. The results indicated greater accuracy on the right target and greater consistency on both targets for the external focus condition, regardless of task difficulty. Our results uniquely demonstrated how instruction modified a speed-accuracy task.     

Benefits of Blocked Over Serial Feedback on Complex Motor Skill Learning

The effects of blocked versus serial feedback (FB) on the learning of a complex motor skill-the production of slalom-type movements on a ski-simulator-were examined. FB was given about force onset, which is considered to be a measure of movement efficiency; relatively late force onsets characterize expert performance. One group of participants (blocked FB; n = 10) received FB about 1 foot per day; for example, for the right foot on Days 1 and 3 and for the left foot on Days 2 and 4. For another group (serial FB; n = 10), the foot about which FB was received was switched on consecutive trials on each of 4 days of practice. Learning was assessed on no-FB trials at the beginning of Days 2, 3, and 4, and on Day 5. Even though there were no differences between groups in force onset, the blocked FB group produced significantly larger movement amplitudes and higher movement frequencies than the serial FB group on the retention test on Day 5. Thus, contrary to the learning of more simple skills (e.g., T. D. Lee & H. Carnahan, 1990), constantly changing the movement component that FB is provided about did not seem to be beneficial for the learning of more complex skills. The findings add to the increasing evidence showing that practice variables that have been shown to enhance the learning of simple skills can actually be detrimental to the learning of complex skills.     

Selective Synaptic Plasticity within the Cerebellar Cortex Following Complex Motor Skill Learning

Complex motor skill learning, but not mere motor activity, leads to an increase in synapse number within the cerebellar cortex. The present experiment used quantitative electron microscopy to determine which synapse types were altered in number. Adult female rats were allocated to either an acrobatic condition (AC), a voluntary exercise condition (VX), or an inactive condition (IC). AC animals were trained to traverse an elevated obstacle course requiring substantial motor coordination to complete. VX animals were housed with unlimited access to running wheels and IC animals received no motor training but were handled briefly each day. Results showed the AC animals to have significantly more parallel fiber to Purkinje cell synapses than both the VX and IC animals. No other synapse type was significantly altered. Thus, the learning-dependent increase in synapse number observed within the cerebellar cortex is accomplished primarily through the addition of parallel fiber synapses.     

Engaging Environments Enhance Motor Skill Learning in a Computer Gaming Task

Engagement during practice can motivate a learner to practice more, hence having indirect effects on learning through increased practice. However, it is not known whether engagement can also have a direct effect on learning when the amount of practice is held constant. To address this question, 40 participants played a video game that contained an embedded repeated sequence component, under either highly engaging conditions (the game group) or mechanically identical but less engaging conditions (the sterile group). The game environment facilitated retention over a 1-week interval. Specifically, the game group improved in both speed and accuracy for random and repeated trials, suggesting a general motor-related improvement, rather than a specific influence of engagement on implicit sequence learning. These data provide initial evidence that increased engagement during practice has a direct effect on generalized learning, improving retention and transfer of a complex motor skill.     

Dependence on Visual Feedback During Motor Skill Learning in Alzheimer's Disease

Three experiments examined the role of visual feedback on the performance of a fine motor task, namely the rotary pursuit, in patients with Alzheimer's disease (AD) and healthy older adults. After extensive practice tracking a fully visible target, participants in Experiments 1 and 2 were tested under restricted vision (RV) conditions. In both experiments, the two groups showed a drop in performance when vision was restricted, with AD patients showing a significantly larger decline. Tracking improved significantly in normal controls, but not AD patients across the RV trials after the initial drop. When difficulty of the rotary pursuit task was manipulated in Experiment 3 without restricting vision, AD patients and normal controls showed identical patterns of performance. Consequently, it could be concluded that AD patients in the first two experiments were relying more heavily on visual information for accurate performance of the tracking task than their healthy peers.     

Variability of Practice and Contextual Interference in Motor Skill Learning

The purpose of this study was to investigate whether learning benefits in multiple-task learning situations are a result of contextual interference or of schema enhancement related to the amount of variability in the practice session. Two experiments were designed that replicated and extended the experiment reported by Wulf and Schmidt (1988). In a 2 (same vs. different relative time) x 2 (blocked vs. random practice schedule) design, 48 right-handed subjects were randomly assigned to one of four experimental conditions. A tapping task was employed that required a right-handed tap of three small brass plates arranged in a diamond pattern. Each segment had a specific time requirement. Target times and response times were provided on a computer screen directly in front of the subject. Each subject participated in two acquisition sessions (i.e., 198 practice trials) and was tested for learning on several different retention and transfer tests. In Experiment 2, a control group was added that received no acquisition phase. Results of both experiments showed a typical contextual interference effect, with depressed scores by the random groups during acquisition but significantly better scores than the blocked groups on several retention and transfer tests. Certain characteristics of the tests were found to influence the demonstration of the practice schedule effects. These results were consistent with predictions from Magill and Hall (1990) that the learning benefits of contextual interference are more likely to occur when skill variations are from different classes of movement and that the amount of variability in practice is more influential when the to-be-learned tasks are parameter modifications of the same generalized motor program.     

Self-Regulated Learning of a Motor Skill Through Emulation and Self-Control Levels in a Physical Education Setting

This study examined the effectiveness of the second and third level of Zimmerman's (2000) model of self-regulated learning development. Participants were 72 (28 boys and 44 girls) fifth- and sixth-grade students who practiced the novel task of dart-throwing. Results showed that sixth-grade Greek students who proceeded sequentially from the emulation to the self-control level improved their dart-throwing performance more than students who missed one or both of these levels, but fifth-grade students benefited equally either from the sequential practice at the emulation and the self-control level or from the experience at one of these self-regulatory levels. No differences were found in self-efficacy, although sixth-grade students who practiced at the emulation level reported higher satisfaction, and sixth-grade students who practiced at the self-control level reported higher intrinsic motivation compared to control group students. These results attest to the effectiveness of learning at the emulation and self-control levels and are discussed with reference to the social cognitive model of self-regulation development.     

Neurocognitive Contributions to Motor Skill Learning: The Role of Working Memory

ABSTRACT

Researchers have begun to delineate the precise nature and neural correlates of the cognitive processes that contribute to motor skill learning. The authors review recent work from their laboratory designed to further understand the neurocognitive mechanisms of skill acquisition. The authors have demonstrated an important role for spatial working memory in 2 different types of motor skill learning, sensorimotor adaptation and motor sequence learning. They have shown that individual differences in spatial working memory capacity predict the rate of motor learning for sensorimotor adaptation and motor sequence learning, and have also reported neural overlap between a spatial working memory task and the early, but not late, stages of adaptation, particularly in the right dorsolateral prefrontal cortex and bilateral inferior parietal lobules. The authors propose that spatial working memory is relied on for processing motor error information to update motor control for subsequent actions. Further, they suggest that working memory is relied on during learning new action sequences for chunking individual action elements together.     

The Acquisition of Time Properties Associated with a Sequential Motor Skill

Three experiments are reported that examined the relative importance of phasing and duration training in the motor learning of a sequential task. In all three experiments, the task involved knocking down three barriers in a specified order. The Phasing task required the subject to contact each of the barriers in a particular goal time interval, that is, each segment had a particular movement-time goal. The Duration task required the subject to contact the final barrier in a total elapsed-time goal defined by the experimenter. Following training, half of the subjects in each training condition transferred to either a novel Duration or a novel Phasing task. Phasing-trained subjects, compared to Duration-trained subjects, produced equivalent transfer performance on the Duration transfer task but superior performance on the Phasing transfer task. These results suggest that phasing serves as a higher-order source of information for the performer in a sequential motor task. In addition, these experiments complement and extend previous work by Shapiro (1977) and Summers (1975) which demonstrated that learned phasing patterns were not modified despite changes in the overall rate of performing a motor sequence. Our experiments indicate that phasing training increases the performer’s sensitivity to phasing patterns such that novel temporal patterns can be produced when they are well-defined.     

Motor Skill Learning and the Development of Visual Perception Processes Supporting Action Identification

This study examined physical training and observational training influences on motor learning and the development of visual discrimination processes. Participants were trained on a bimanual task (relative phase of +90°) defined by a visual training stimulus. There were 2 observational contexts: 1) model-only, watch a learning model, and 2) stimulus-only, watch the visual training stimulus. After 2 d of training, the learning models performed the +90° pattern with reduced error in 2 retention tests. Each observer group showed improvement in performance of the +90° pattern, with the stimulus-only group characterized by a more significant improvement. The learning models and observer groups were characterized by an improvement in visually discriminating 2 features of the trained pattern, relative phase and hand-lead. Overall, physical practice (learning models) established a stronger link between the action and visual discrimination processes compared with the observational contexts. The results show that the processes supporting action production and the visual discrimination of actions are modified in ways specific to the trained action following both physical and observational training.     

Effect of Four Fatigue Levels on Performance and Learning of a Novel Dynamic Balance Skill

This study was to investigate the effect of fatigue on the performance and learning of the Bachman ladder task to determine if the relationship between activation and both the performance and learning data would support the inverted-U theory. Male Ss (N=48) were randomly assigned to four groups. A level of fatigue as determined by HR (Control, 120 BPM, 150 BPM, and 180 BPM) was assigned to each group. Each S was fatigued to his assigned level prior to the task and following each trial, was given 20 trials on Day 1 to learn the task while at his designated level, and then was given 20 additional trials on Day 2 under control conditions. On Day 1 150 and 180 BPM impaired performance of the motor task. The learning score data indicated that 150 and 180 BPM had a detrimental effect on learning of the task. Both the activation-performance and the activation-learning relationships partially supported the inverted-U theory.     

Examining the Preferred Self-Controlled KR Schedules of Learners and Peers During Motor Skill Learning

In many practical situations, learners are provided with feedback in the form of knowledge of results (KR) by a peer. However, when peers provide KR is currently unknown. When given the opportunity to request KR in a self-controlled manner, some participants have reported a preference for requesting KR after good performances. Alternatively, peers may provide KR in a different fashion. Subsequently, a discrepancy between the learner's desire to receive KR and when a peer provides KR may arise. In our study, peer- and self-controlled KR schedules were compared. Participants were peers who controlled KR (PC; 8), learners with peers (P-L; 8), or learners with self-control (SC; 8). Participants in the two learning groups (P-L and SC groups) completed a serial-timing task with a goal time of 2500 ms. Absolute error data on KR and no-KR trials along with self-reports indicate that participants with self-control preferred KR after good trials and peers preferred to provide KR after both good and bad trials equally. Results from the delayed retention test indicated that peer-controlled learners were more consistent (i.e., in terms of variable error) than the self-control group.     

The Effect of Fatigue on Learning and Performance of a Gross Motor Task

40 college males were sequentially assigned to 1 of 2 groups to examine the effects of induced physical fatigue upon the performance and learning of a gross motor task, the stabilometer. All Ss were given 32 practice trials over 3 practice sessions, with 48 hr. rest interpolated between sessions. Trials 1 and 2 were performed under control conditions (no fatigue) for both groups. The Experimental Group was then required to perform under conditions of physical fatigue during Trials 3-26. Trials 27-32 (Session 3) were performed under control conditions. The condition of fatigue was achieved on Trials 3-26 by having Ss pedal a bicycle ergometer until a heart rate of 180 beats/min was attained prior to each trial. The Control Group cancelled vowels. The results indicated that physical fatigue was detrimental to the performance and learning of the Experimental Group.     

Effect of an Audience on Performance of a Motor Task

40 College Ss were placed in 4 groups and tested on a star-tracing task on 2 occasions under the following conditions: spectators-no-spectators; spectators-spectators; no-spectators-no-spectators; no-spectators—spectators. It was found that the presence or absence of spectators had no noticeable effect on the initial learning phase as contrasted to later stages of performance. When conditions remained the same on both testing occasions, less errors were made. Speed was generally quicker under altered task conditions.     

The Role of Task Experience and Prior Knowledge for Detecting Invalid Augmented Feedback while Learning a Motor Skill

Two hypotheses were investigated. These were generated from results reported by Buekers, Magill, and Sneyers (1994) and an uncertainty account of those and other effects on skill learning of erroneous knowledge of results (KR). The first hypothesis proposes that if experienced performers have developed the capability of detecting and correcting errors, then they should not be influenced by erroneous KR in the same way as novices. The second proposes that if information about the invalid feedback is given to subjects prior to the beginning of the practice trials, then the capability for assessing feedback can be accelerated such that subjects who receive this advance information should not be misled by the erroneous KR. The first hypothesis was investigated in Experiment 1 by having subjects practise an anticipation timing task for 450 trials. One group received correct KR on all trials, and another group received no KR. Half of the subjects in each group were unexpectedly switched to erroneous KR after 400 trials. Results indicated that the erroneous KR influenced both groups during acquisition and on a retention test one minute later. However, on a retention test given one week later, only the group that had practised with no KR before being switched to erroneous KR continued to show the negative influence of the invalid KR. The second hypothesis was examined in Experiment 2 by telling subjects prior to beginning practice trials that it was possible that the KR they received would be erroneous. Results showed that this intervention strategy was effective on the no-KR retention tests only for subjects who had no-KR trials alternated with trials on which they received the erroneous KR. The results of these experiments provide evidence that uncertainty about the validity of sensory feedback increases the likelihood that subjects will be misled by invalid augmented feedback. Moreover, this uncertainty can be overcome by increased experience or by providing advance knowledge about the nature of the invalid feedback.     

Perceptual Effect on Motor Learning in the Serial Reaction-Time Task

Although the Serial Reaction-Time Task has been an effective tool in studying procedural learning, there is still a debate as to whether learning in the task is effector-based, stimulus-based, or response-based. In this article, the authors contribute to this debate by contrasting response- and stimulus-based learning by manipulating them selectively and simultaneously. Results show that (a) participants learned response sequences in the absence of stimulus-specific perceptual sequence information but (b) not stimulus sequences without corresponding response information. In a third condition, response sequence and stimulus frequency information were in conflict, and each effect decreased learning in the other domain. Overall, our findings show that learning in these tasks is primarily motor-based, but it is also constrained by relatively salient perceptual information. Together with earlier findings in the literature, the findings also suggest a task and stimulus-arrangement-specific interaction between motor and perceptual learning, where relevance and salience of the specific information plays a crucial role.     

Influence of Expertise on the Intentional Transfer of Motor Skill

Intentional transfer of expert knowledge is an important issue in cognitive science and motor skills. How subjects deliberately transfer expertise in karate when learning a closely related motor skill (tai chi) was examined in this study. Subjects (N = 20) learned a videotaped sequence of self-defense movements, evaluated their learning, and then performed the sequence. Self-regulation of learning is believed to be central to effective transfer. The measures of self-regulation were accuracy of self-evaluation, video use, and approach to learning. Results showed that unlike novices, experts used self-regulation, learning strategies, and the video player in more complex ways in self-regulation. Experts, as compared with novices, demonstrated their greater knowledge through the higher quality of their performance and their better comprehension of movement meaning; but both groups recalled an equal number of moments, suggesting that both experts and novices transferred general knowledge about learning.     

The Effect of External and Internal Focus of Attention on Gait Variability in Older Adults

Internal focus of attention on a movement or focusing on an external target are both strategies that can affect motor performance. The authors explored whether manipulating subjects' focus of attention while walking would alter gait variability, a measure reflecting consistency of gait and associated with the risk of falling in older adults. Twenty community-living older adults participated in the study and were tested while focusing their attention on (a) gait consistency (internal focus) or (b) metronome beats (external focus). In both conditions gait variability increased (i.e., worsened p < .05) or did not change. No benefit was found in instructing subjects to focus on gait consistency or metronome beats. Such instructions may actually have distracted and interfered with the execution of gait.