Intact Procedural Knowledge in Patients with Alzheimer's Disease: Evidence from Golf Putting

Can Alzheimer's disease (AD) patients efficiently learn to perform a complex motor skill when relying on procedural knowledge? To address this question, the authors compared the golf-putting performance of AD patients, older adults, and younger adults in 2 different learning situations: one that promotes high error rates (thus increasing the reliance on declarative knowledge) or one that promotes low error rates (thus increasing the reliance on procedural knowledge). Motor performance was poorer overall for AD patients and older adults relative to younger adults in the high-error condition but equivalent between similar groups in the low-error condition. Also, AD patients in the low-error condition had better performance at the final putting distance relative to those in the high-error condition. This performance facilitation for AD patients likely stems from intact procedural knowledge.     

Effect of Instructions Prioritizing Speed or Accuracy on Kinematics and Kicking Performance in Football Players

The authors' purpose was to investigate if there is a speed accuracy trade-off in soccer kicking by using instructions prioritizing velocity, accuracy, or both upon soccer kicking performance and kicking direction in experienced soccer players. In addition, kinematics were measured to investigate the eventual differences in performance. Thirteen experienced male footballers performed penalty kicks with different instructions prioritizing velocity, accuracy or both. Three-dimensional kinematics, together with maximal ball velocity and hitting accuracy, were measured on all kicks. The main findings were that when the main aim was accuracy, accuracy increased, while the velocity reduced, which supports Fitts' law (Fitts, 1954 Fitts, P. M. (1954). The information capacity of the human motor system in controlling the amplitude of movement. Journal of Experimental Psychology, 47, 381–391.[Crossref], [PubMed] , [Google Scholar]). In addition, kicking accuracy was higher when kicking to the contralateral side. The slower ball velocity was caused by lower segmental and in run velocities. These lower segmental velocities were mainly caused by the lower maximal knee extension and pelvis rotation during the accuracy priority kicks.     

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 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.     

EMG Activity as a Function of the Performer's Focus of Attention

In previous studies of attentional focus effects, investigators have measured performance outcome. Here, however, the authors used electromyography (EMG) to determine whether differences between external and internal foci would also be manifested at the neuromuscular level. In 2 experiments, participants (N = 11, Experiment 1; N = 12, Experiment 2) performed biceps curls while focusing on the movements of the curl bar (external focus) or on their arms (internal focus). In Experiment 1, movements were performed faster under external than under internal focus conditions. Also, integrated EMG (iEMG) activity was reduced when performers adopted an external focus. In Experiment 2, movement time was controlled through the use of a metronome, and iEMG activity was again reduced under external focus conditions. Those findings are in line with the constrained action hypothesis (G. Wulf, N. McNevin, & C. H. Shea, 2001), according to which an external focus promotes the use of more automatic control processes.     

The Functional Role of Cognitive Frameworks on Visuomotor Adaptation Performance

The authors investigated the effects of cognitive representations of movement directions on sensorimotor adaptation performance. Adaptation performance was measured via a pointing experiment in which participants were provided with visual feedback that was distorted along the midsagittal plane (i.e., left-right reversal). Performance was analyzed relative to participants’ individual adaptation gains and 3 groups were subsequently defined (i.e., skilled, average, and poor adapters). The group separation was kept for the Cognitive Measurement of Represented Directions, which was used to analyze participants’ cognitive representation of movement directions. The results showed that skilled adapters, in contrast to poor adapters, possess a global representation of movement directions aligned to the cardinal axes. The cognitive representation structure hence supports the sensorimotor adaptation performance.     

Haptic Guidance Can Enhance Motor Learning of a Steering Task

Haptic guidance can improve the immediate performance of a motor task by enforcing a desired pattern of kinematics, but several studies have found that it impairs motor learning. In this study, we studied whether guidance from a robotic steering wheel can improve one's short-term learning of steering a simulated vehicle. We developed a computer algorithm that adapted the firmness of the guidance based on ongoing error. Training with "guidance-as-needed" or "fixed guidance" allowed participants to learn to steer without experiencing large errors and produced slightly better immediate retention than did training without guidance, apparently because participants were better able to learn when to initiate turns. Training with guidance-as-needed produced slightly better results than training with fixed guidance: the guidance-as-needed participants' errors were significantly smaller when guidance was removed. However, this difference quickly dissipated with more practice. We conclude that haptic guidance can benefit short-term learning of a steering-type task while also limiting performance errors during training.     

The Influence of Attentional Focus on Balance Control over Seven Days of Training

This study examined the training effect of attentional focus (external focus, internal focus, or no focus instructions) on a dynamic balance task. Participants completed baseline balance testing, seven consecutive days of dynamic balance board training, and retention testing 24 hours after the last session. The novel finding of this study was the presence of a training effect on balance control when adopting an external focus relative to an internal focus or no focus instructions. Further, we report the unique observation that more patterned behavior was adopted regardless of the focus instructions. These findings provide insight into how instructions can be altered to enhance human balance control and complement the constrained-action hypothesis.     

言语与空间任务指令对数字-空间联结编码的影响

以1～9除5外的阿拉伯数字和汉字标签“左”“右”为实验材料,采用数字奇偶判断任务,探讨任务指令对数字-空间联结编码的影响。结果发现：言语任务指令条件下,词语一致性与物理一致性的交互作用显著,且词语一致和不一致时均未发现空间-数字联合反应编码效应（SNARC）,表明言语-空间编码在数字-空间联结中更有优势;空间任务指令条件下,物理一致性主效应显著,且词语一致和不一致时均出现了SNARC效应,表明视觉空间编码更有优势。说明数字-空间联结编码受实验任务指令的影响,被试会根据任务指令设置的情景选择视觉空间编码或言语-空间编码对数字进行空间联结。     

任务指导语及实验范式对朝向和反向眼跳的影响

采用2（眼跳方向）×3（实验范式）×4（任务指导语）的完全被试内实验设计研究任务指导语和实验范式对朝向和反向眼跳的影响效应。结果：（1）朝向眼跳潜伏期显著快于反向眼跳,且不受实验范式的影响;（2）在朝向眼跳任务中,空白范式下的延迟型指导语导致眼跳潜伏期延长;（3）在反向眼跳任务中,空白和重叠范式下延迟型指导语潜伏期最长;零范式下速度型指导语的潜伏期较短;（4）空白范式下的反向眼跳错误率显著低于重叠范式和零范式,反向眼跳潜伏期显著短于后两种范式。实验结果支持眼跳竞争模型。     

Training Motor Sequences: Effects of Speed and Accuracy Instructions

Participants practiced a fixed 3- and a fixed 6-key press sequence for 144 times each. In the speed group, they were instructed to execute their sequences fast without bothering much about errors while the accurate group was instructed to be careful and prevent errors. In the test phase, participants executed series of 3 and 6 responses (a) when all element-specific stimuli were displayed in the familiar order, (b) in response to just the familiar first stimulus, and (c) by responding to random stimuli. The speed instruction yielded stronger sequencing skill while the accuracy instruction developed stronger reaction skill.     

Compensatory Coordination of Release Parameters in a Throwing Task

The consistency and coordination of release parameters in ball-throwing movements were investigated. The authors used a newly developed index of coordination for release parameters (ICRP) that quantifies the degree of improvement of performance consistency caused by compensatory relationships among parameters (i.e., not caused by consistency of parameters). Eight participants practiced for 150 trials, with the nondominant hand, a ball-throwing task aimed at a stationary target. The magnitude of the ball-release velocity vector, among release parameters, as well as the performance was found to become consistent with practice. The ICRP score suggested that the release parameters were complementarily coordinated with one another, and that the coordination improved with practice. Those results indicate that compensatory relationships among varying release parameters contribute to reducing the variability of performance in a ball-throwing task whose goal is accuracy.     

The Effect of Practice on Human Performance in a Preview-Constrained Motor Control Task

This study examined the effect of short-term practice on the parameters of a linear model involving mean arm movement time as a function of Fitts’s index of difficulty (ID) variable and a preview-constraint ID variable. Significant (at the 2% level) interactions were found to exist between practice and the two ID variables indicating that the model parameters associated with these variables are both linear functions of practice time.     

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.     

大鼠注意定势转移任务模型的深入研究：种系和检测程序的影响

注意定势转移任务(attentional set-shifting task, AST)可用于特异性检测啮齿类动物前额叶皮层及其皮层下神经通路介导的认知灵活性, 是目前研究认知灵活性及其障碍神经基础的重要模型。本研究系统调查了大鼠种系和检测程序差异对AST结果的影响。通过比较Wistar和Sprague Dawley (SD)两个种系大鼠在七阶段和五阶段两种AST检测程序中的认知表现, 研究发现：(1) SD和Wistar大鼠前额叶认知功能存在差异, 后者的总体认知表现优于前者。尤其是Wistar大鼠在逆反学习阶段的达标训练次数及错误率显著低于SD大鼠, 表明Wistar大鼠具有更高的策略转换灵活性。(2)在AST测试中逆反学习和外维度定势转移是认知灵活性评价的核心指标。这两种认知转换过程分别以前期策略和注意定势建立为基础。结果显示在两种AST检测程序中Wistar和SD大鼠在逆反学习和/或外维度定势转移等复杂学习阶段的达标训练次数和错误率均高于其它简单关联学习阶段, 表明在目前实验条件下大鼠均表现出定势形成和转换困难的反应模式, 不同认知反应间的结构关系具有稳定性。这些结果提示大鼠前额叶皮质介导的认知灵活性存在种系差异, AST各阶段认知反应间的结构效度不受目前使用的大鼠种系和检测程序差异的影响, 扩展了对AST模型的认识。     

Consistent and Variable Practice Conditions: Effects on Relative and Absolute Timing

The authors conducted the present experiments to resolve the discrepancy between studies in which relative-timing learning has been found to be enhanced by consistent practice conditions and contextual interference experiments in which relative-timing learning has been found to be enhanced more by random practice than by blocked practice. There were 40 participants in Experiment 1 and 48 in Experiment 2. The results of Experiment 1 extended previous findings: The learning of the relative-timing pattern was systematically enhanced by the degree to which the practice conditions promoted movement consistency (constant > blocked > serial > random). Experiment 2 provided evidence that the discrepancy between the relative-timing effects in the 2 groups of studies was a product of the way in which relative-timing goals and feedback were presented. When the feedback was presented as segment times, random practice resulted in generally more stable relative-timing patterns during acquisition than blocked practice did. Thus, in both experiments, the learning of the relative-timing pattern was enhanced by more stable relative-timing conditions during acquisition. Absolute-timing learning, as indexed by the transfer tests, was enhanced by serial or random practice as compared with constant or blocked practice, and was relatively unaffected by feedback conditions directed at the relative-timing pattern. In terms of motor programming theory, those findings are taken as additional evidence for the disassociation of memories supporting generalized motor program (GMP) performance, as indexed by relative timing, and parameter performance, as indexed by absolute timing.     

Performance and Learning of Generalized Motor Programs: Relative (GMP) and Absolute (Parameter) Errors

The effects of practice (Experiment 1) and parameter variability (Experiment 2) on the learning of generalized motor programs (GMPs) and movement parameterization were investigated In each experiment, 2 tasks with different relative force-time structures were tested. Participants (N = 32, Experiment (N = 40, Experiment 2) attempted to exert a pattern of force that resembled in force and time a waveform that was displayed on a computer monitor. In both experiments, the analysis suggested that the GMP, although refined over practice, was relatively stable (i.e., resistant to decay and interference), even early in practice (after 20 trials). In addition, the results indicated that constant and variable parameter practice did not differentially affect GMP learning but did degrade the learning of the parameter that was not varied. The data provided additional evidence for the dissociation of the GMP and the parameterization processes proposed in GMP theory. Contrary to schema theory, the present data suggest an interdependence between the force and the time parameters: The manipulation of 1 of the parameters has a negative effect on the learning of the other parameter.     

The Effect of Mental Practice on Performance in a Sequential Reaction Time Task

The effect of mental practice on performance in a dot-location RT task was investigated. Participants (N = 40) were required either to mentally practice, physically practice, or do no practice on an RT task in which the signals appeared in a repeating sequence. Correct mental practice, as opposed to incorrect mental practice and no practice, was predicted to have a positive (enhancing) effect on performance of the RT task. Despite previous evidence that mental rehearsal does enhance performance in many perceptual-motor tasks, neither correct nor incorrect mental rehearsal affected subsequent sequence learning; that is, no mental practice effect was observed. That surprising result is discussed in terms of motivational, psychoneuromuscular, separate memory systems, and transfer-appropriate processing explanations of mental practice.     

The Effects of Force and Direction Uncertainty on Choice Reaction Time in an Isometric Force Production Task

The two experiments reported examined the temporal organization of force and direction motor-programming processes in a step-input tracking type task. Both experiments observed a reduction in reaction time in the direction-uncertain conditions compared to the direction-certain ones. Thus it seems as though the direction decision does not have to precede the selection of the proper amount of force. Experiment 2 observed an underadditive interaction between levels of direction uncertainty (certain or uncertain) and levels of force uncertainty (certain or uncertain). This interaction was interpreted as support for a parallel organization of the processes responsible for the programming of force and direction and thus, strongly supports the parallel model of programming recently proposed by Klapp (1977a, b).