Organization and learning of visual-motor information during different orders of limb movement: step, velocity, acceleration

Theoretical use of the tracking paradigm as a means of understanding perceptual-motor organization has been influenced by ambiguous assumptions concerning the relation of time orders of force production to the learning and performance of time orders of limb movement. This study provides both a conceptual framework for clarifying these assumptions, and empirical data for testing them. The independent variables were (a) target motion (step, velocity, acceleration); (b) stick loading (elasticity, damping, mass); and (c) practice. The dependent variables were absolute terror for step and time-integrated squared error for velocity and acceleration. The hypothesis was that proficiency of tracking is inversely related to mathematical complexity of reactive forces, within constraints imposed by familiarity with required types of transfer functions. Five subjects were assigned to track one type of target motion in each of the three loading conditions, respectively. Cursor-present "training" trials were alternated with cursor-absent "test" trials. Thereby, a premium was placed on attention to proprioceptive feedback, at least at the start of training. The hypothesis could not be rejected.     

Noncontingent positive and negative feedback during maximal exercise.

A closed skill, maximal effort on a bicycle ergometer was used to study the effects of noncontingent external feedback on performance, perceived effort, and the subject's assessment of the quality and accuracy of the feedback. The 47 subjects included elite athletes as well as physical education majors. They were asked to perform a series of 5 60-sec. trials of maximal effort, trials which included positive, negative, positive and negative, and no-feedback conditions. Although there were no significant effects on performance for the various feedback conditions, subjects judged the positive feedback favourably and as accurate, but negative feedback was judged unfavourably and considered to be inaccurate. This result is seen as supportive of the 1982 McCarrey, et al. supposition that successful athletes may have less need to internalize attributions of effect.     

Preconditioning of reinforcing properties to an exteroceptive feedback stimulus

Three groups of rats were given Pavlovian preconditioning by means of a yoking procedure and subsequently trained to avoid. One group received a light stimulus during preconditioning at the same times as the master avoiding animals received an exteroceptive feedback stimulus. During the subsequent avoidance training, this group was then given the same light stimulus as a feedback stimulus on successful avoidance trials. The group learned two-way avoidance in about the same number of trials as one-way avoidance is typically learned and substantially faster than two other control groups. These data indicate that feedback stimuli develop reinforcing properties by a Pavlovian mechanism. The data of the control groups indicate that feedback stimuli do not provide “information” about responding in the present situation.     

Online versus offline processing of visual feedback in the control of movement amplitude

Researchers have suggested that visual feedback not only plays a role in the correction of errors during movement execution but that visual feedback from a completed movement is processed offline to improve programming on upcoming trials. In the present study, we examined the potential contribution of online and offline processing of visual feedback by analysing spatial variability at various kinematic landmarks in the limb trajectory (peak acceleration, peak velocity, peak negative acceleration and movement end). Participants performed a single degree of freedom video aiming task with and without vision of the cursor under four criterion movement times (225, 300, 375 and 450 ms). For movement times of 225 and 300 ms, the full vision condition was less variable than the no vision condition. However, the form of the variability profiles did not differ between visual conditions suggesting that the contribution of visual feedback was due to offline processes. In the 375 and 450 ms conditions, there was evidence for both online and offline control as the form of the variability profiles differed significantly between visual conditions.     

Anticipatory modulation of precision grip force with variations in limb velocity of a curvilinear movement

The authors examined the relationship between peak velocity of a discrete horizontal elbow flexion movement in which the hand path was curvilinear and premovement modulation of precision grip force. The velocity of the movements of 7 participants was varied from maximal velocity to a velocity that required several seconds to reach a target. An object instrumented with force transducers for the forefinger and thumb measured precision grip force. There was a positively accelerating quadratic relationship between grip force change before movement and peak velocity of the ensuing limb movement. On some low-velocity trials, premovement grip force modulation reflected a net decrease. In contrast, high-velocity trials were preceded by net increases in grip force. Using cluster analysis, the authors classified grip forces in low-velocity movements as an empirically distinct set of entities from grip forces in high-velocity movements. The cluster of high-value grip forces suggested an anticipatory strategy that allowed participants a large safety margin in grip force to avoid object slip on movement initiation. The cluster of low-value grip forces at movement initiation suggested a second anticipatory strategy in which participants changed grip force very little, perhaps to increase the ability of proprioceptors in the hand to sense force changes. Those findings suggest that modulation of grip force before initiation of movements in which the hand path is curvilinear may be governed by two distinct velocity-dependent anticipatory strategies.     

How to improve movement execution in sidestep cutting? Involve me and I will learn

Providing choices, i.e., autonomy, to athletes during practice increases intrinsic motivation and positively influences the motor learning process. The effects of autonomy on the timing of feedback (self-controlled timing of feedback) when optimizing the movement execution of sidestep cutting (SSC), a task that is highly related with ACL injury risk, are unknown. The aim of this study was to investigate the effect of self-controlled timing of video and EF-feedback on movement execution of SSC in team sport athletes. Thirty healthy ball team sport athletes (22.9 ± 1.7 years, 185.5 ± 7.2 cm, 79.3 ± 9.2 kg) were recruited from local sports clubs. Participants were alternately assigned to the self-control (SC) or the yoked (YK) group based on arrival and performed five anticipated and five unanticipated 45° SSC trials as pre-, immediate-post and one-week retention test. Movement execution was measured with the Cutting Movement Assessment Score (CMAS). Training consisted of three randomized 45° SSC conditions: one anticipated and two unanticipated conditions. All participants received expert video instructions and were instructed to ‘try to do your best in copying the movement of the expert’. The SC group was allowed to request feedback whenever they wanted during training. The feedback consisted of 1) CMAS score, 2) posterior and sagittal videos of the last trial and 3) an external focus verbal cue on how to improve their execution. The participants were told to lower their score and they knew the lower the score, the better. The YK group received feedback after the same trial on which their matched participant in the SC group had requested feedback. Data of twenty-two participants (50% in SC group) was analyzed. Pre-test and training CMAS scores between groups were equal (p > 0.05). In the anticipated condition, the SC group (1.7 ± 0.9) had better CMAS scores than the YK group (2.4 ± 1.1) at the retention test (p < 0.001). Additionally, in the anticipated condition, the SC group showed improved movement execution during immediate-post (2.0 ± 1.1) compared to pre-test (3.0 ± 1.0), which was maintained during retention (p < 0.001). The YK group also improved in the anticipated condition during immediate-post (1.8 ± 1.1) compared to pre-test (2.6 ± 1.0) (p < 0.001) but showed decreased movement execution during retention compared to immediate-post test (p = 0.001). In conclusion, self-controlled timing of feedback resulted in better learning and greater improvements in movement execution compared to the control group in the anticipated condition. Self-controlled timing of feedback seems beneficial in optimizing movement execution in SSC and is advised to be implemented in ACL injury prevention programs.     

The attenuation effect in timing: counteracting dual-task interference with time-judgment skill training

A basic finding in the time-perception literature is an interference effect in dual-task conditions involving concurrent timing and distractor tasks. Dual-task conditions typically cause time judgments to become less accurate than single-task conditions in which subjects judge time alone. Previous research (Brown, 1998 Psychological Research 61 71-81; Brown and Bennett, 2002 Psychological Research 66 80-89) has shown that practice on the distractor task reduces interference, a phenomenon called the attenuation effect. The present research was designed to determine whether practice on the time-judgment task would produce a similar result. In experiment 1, subjects reproduced 6-14 s intervals in a series of practice trials. Some subjects received feedback regarding the accuracy of each response and others received no feedback. Subsequent testing under dual-task (timing + digit memory) conditions showed that feedback training reduced interference. In experiment 2, the practice trials included both single-task and dual-task conditions. Later tests showed that feedback training eliminated the interference effect. The results highlight the role of attentional resources, the transfer of skills, and compensatory decision processes in time-judgment skill training.     

Error feedback and the acquisition of geographical representations

Three training conditions were compared in a task of learning locations of cities on a map: One in which participants could avoid errors by searching for the name of the correct city, and two others in which either immediate feedback after each response or delayed feedback after all responses had been made was given. Learners who received feedback only after placing all the cities on the map performed more poorly overall during training but outperformed the other two groups in both immediate and delayed tests. This advantage is interpreted as evidence of differential development of relational knowledge and application of cognitive effort across training conditions. Copyright © 2007 John Wiley & Sons, Ltd.     

Increased Sensitivity to Changes in Visual Feedback With Practice

In recent work investigating motor learning, the focus has been on the effect of modifying feedback at different levels of learning. Results suggest that learning is specific to the practiced conditions and that this specificity increases with practice. In a replication and extension of this previous work, 3 groups (N = 30 subjects) practiced a sequential positioning movement: Controls performed 300 trials with visually presented on-line kinematic feedback, whereas the other 2 groups, low practice (LP) or high practice (HP), performed, respectively, 50 or 300 trials without feedback. Pretest and posttest sessions of 10 trials each were performed with the on-line feedback. All groups improved with practice. It was apparent that the HP group exhibited more of a performance decrement in the postest than the LP group did, suggesting that motor learning is the process of forming an increasingly specific sensorimotor representation. These results have implications for motor learning paradigms, models of motor learning, and training.     

Impact of esteem-related feedback on mood, self-efficacy, and attribution of success: Self-enhancement/self-protection

It is suggested that positive ego-enhancing and negative ego-diminishing feedback conditions concerning social perceptiveness can give rise to altered affective states concerning self-esteem that generalize to other areas of cognitive functioning in such a way that this feedback accompanies a systematic self-serving attributional bias of cognitive/intellectual performance. The results of 40 participants in an ego-enhancing and 45 in an ego-diminishing feedback condition indicate more attribution of problem-solving success by the first group to effort and to ease of the task; participants who received ego-diminishing feedback attributed their initial problem-solving success less to ease of the task. Other more direct evidence of self-protective strategies on the part of those in the ego-diminishing feedback condition includes lower success expecta y on retest and reduced volunteering for additional challenge. The results are interpreted as evidence of the impact of generalized esteem-related affect on future success expectancy, on risk-taking, and on the attribution of success when future replication is a boundary condition.     

The Role of Concurrent Feedback in Learning to Walk Through Sliding Doors

Concurrent feedback is defined as information about performance given to participants during the execution of an action. This article investigates whether concurrent feedback is beneficial or detrimental to the learning of an ecologically relevant task. Eighteen participants were asked to walk through a virtual corridor and they practiced over 1110 trials to adjust their walking speed so as to pass through sliding doors that opened and closed at a frequency of 1 Hz. Concurrent feedback informed them about the possible need to accelerate or decelerate. Performance of participants who received concurrent feedback on 66% of the practice trials (on average) did not differ significantly from performance of participants who did not receive concurrent feedback. Furthermore, participants of both of these groups significantly outperformed participants who received concurrent feedback on all practice trials. These results are discussed in relation to the perceptual-motor mechanisms that underlie the control of the action. Also discussed are implications for future research, including the use of self-controlled feedback and the use of multisensory training programs.     

Conflict of Interests and Commitment in Groups1

Behavioral commitment levels of group members were examined under conflict of interests between individual and collective tasks in a work-group scenario. Commitment was conceptualized as the amount of time and effort resources that individuals chose to allocate to the group task. Seventeen groups of three allocated 100 time and effort resource units to individual and group tasks for each of four trials. The level of commitment to group work increased, partially because over-rewarded persons increased group contributions more than underrewarded persons decreased them. However, the variance of allocations to the group task did not decrease over trials. Potential implications of the findings for organizational research and practice concerning work groups are discussed in terms of the roles of equity, comparative referent use, and information exchange.     

基于即时反馈的反应抑制训练对青少年和成人执行功能的训练效应和迁移效应

本研究以基于即时反馈的Stop Signal范式为训练任务, 考察3周训练是否对青少年和成人的执行功能产生训练效应和迁移效应。发现青少年、成人实验组和积极控制组都出现了训练效应。两个实验组均产生了对反应抑制Go/No-go任务的迁移效应; 但只有青少年实验组出现了对干扰抑制Stroop任务的迁移效应。成人实验组和积极控制组都出现了对2-back任务的迁移效应; 但只有青少年实验组出现了在2-和3-back任务上的迁移效应。所有组别都未能出现对推理能力的迁移。研究证明从青春期到成年期, 基于即时反馈的反应抑制训练能够对执行功能产生训练和迁移效应, 但迁移仅限于抑制和工作记忆等基础成分, 无法改善推理能力。     

Goals-feedback conditions and episodic memory: Mechanisms for memory gains in older and younger adults

Research has established that challenging memory goals always lead to score increases for younger adults, and can increase older adults' scores under supportive conditions. This study examined beliefs and on-task effort as potential mechanisms for these self-regulatory gains, in particular to learn whether episodic memory gains across multiple trials of shopping list recall are controlled by the same factors for young and old people. Goals with feedback led to higher recall and strategic categorisation than a control condition. Strategy usage was the strongest predictor of gains over trials for both age groups. Age, goal condition, and effort also predicted scores across the entire sample. Older adults' gains, but not younger adults' gains, were affected significantly by the interaction of self-efficacy beliefs and goal condition, and condition interacted with locus of control to predict younger adult gains. These results emphasise the importance of self-regulatory effort and positive beliefs for facilitating goal-related memory gains.     

Velocity Toward Goal Attainment in Immediate Experience as a Determinant of Affect

An experiment tested a model in which affect reflects rate of movement (velocity) toward one's behavioral goal. Participants responded to an ambiguous task and received false feedback regarding their performance. The pattern of feedback either remained fairly constant at 50% correct, went from low incidence of correct to 50% correct across trials, or went from high incidence of correct to 50% correct across trials. Self-reported mood change (from before the task to the point at which all groups received 50% correct) took the following pattern: Participants moving from frequent correct to 50% correct (low velocity) changed to less positive mood, whereas those moving from infrequent correct to 50% correct (high velocity) tended to change to more positive mood. Discussion centers on convergence between these findings and those of previous research.     

Controlling velocity in rapid movements

It has often been reported that subjects prefer to use a strategy in which they vary movement velocity and peak amplitude in a linear fashion. In this study, control of velocity and amplitude in rapid reciprocating movements of the interphalangeal joint of the thumb was investigated by examining movement trajectories and patterns of activity in the extensor pollicis longus (EPL) and flexor pollicis longus (FPL) muscles. In controlling either amplitude or peak flexion velocity without constraint, subjects always used a strategy in which peak extension velocity and peak flexion velocity had strong linear correlations with movement amplitude. When they were required to keep either amplitude or peak flexion velocity fixed their movements were still biased toward a strategy in which peak velocity and movement amplitude covaried. It is suggested that the preferred strategy is related to a basic principle of scaling the magnitude and duration of a velocity profile in order to achieve different movement amplitudes.     

Motivational effects of teachers' ability versus effort feedback on Chinese students' learning

Schunk (1983) found in his study with U.S. students that teachers' ability feedback (“You're good at this”) had a stronger motivational effect on students' learning than that focusing on effort (“You've been working hard”). The present experimental study examined such differential effects of attributional feedback on 386 elementary and high school Chinese students who were brought up in a culture where effort and endurance were strongly emphasized. Generally, the results with elementary students (Grade 4) replicated Schunk's findings. Mutual reinforcement effects also showed that effort and ability feedbacks combined led to the highest perceived effort expenditure. This research was supported in part by the Hong Kong Institute of Educational Research at the Chinese University of Hong Kong. Correspondence concerning this article should be addressed to Kit-Tai Hau, Faculty of Education, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong.     

Effects of working memory and reading acceleration training on improving working memory abilities and reading skills among third graders

Working memory (WM) plays a crucial role in supporting learning, including reading. This study investigated the influence of reading acceleration and WM training programs on improving reading skills and WM abilities. Ninety-seven children in third grade were divided into three study groups and one control group. The three study groups each received a different combination of two training programs: only reading acceleration, WM followed by reading acceleration, and reading acceleration followed by WM. All training programs significantly improved reading skills and WM abilities. Compared with the control group, the group trained with only the reading acceleration program improved word accuracy, whereas the groups trained with a combination of reading and WM programs improved word and pseudo-word fluency. The reading-acceleration-alone group and the WM-program-followed-by-reading-acceleration group improved phonological complex memory. We conclude that a training program that combines a long reading acceleration program and a short WM program is the most effective for improving the abilities most related to scholastic achievement.     

Concept identification with and without blank trials

The blank trials technique introduced by Levine (1966) has been of considerable importance in the study of concept identification and human discrimination learning, as it provides a means of identifying the hypotheses generating choice responses. However, this technique involves the interpolation between normal feedback trials of several trials during which no feedback concerning the correctness of a subject's responses is given.

An experiment was conducted to study the comparability of concept identification with and without blank trials. No differences in trials to criterion, number of errors, or in presolution latencies were observed. These results tend to justify inferences about normal concept identification from blank trial data, and they also have some implications concerning the role of memory in concept identification.     

控制感剥夺激发状态毅力：趋近动机的中介作用

采用概念判断任务,通过两个递进式实验探索控制感剥夺对状态毅力的影响并考察趋近动机在其中的作用。实验1主观报告结果显示：短时条件下,控制感剥夺组的状态毅力显著高于控制感维持组,尤其表现在努力持续性维度;长时条件下,两组差异不显著。实验2在此基础上加入行为指标结果显示：短时控制感剥夺通过高趋近动机对状态毅力产生影响。结果表明毅力是可塑的,突出表现在努力持续性上,该效应出现在个体经历短时控制感剥夺后。