Are Fast Complex Movements Unimaginable? Pupillometric Studies of Motor Imagery in Expert Piano Playing

Motor imagery (MI; mental simulation of actions) shares certain mental representations and processes with executed movement (ME). This neurocognitive overlap between MI and ME may explain why the systematic use of MI improves skilled performance in numerous domains. Unfortunately, the attentional mechanisms underlying MI remain unresolved. Therefore, the present studies investigated the role of attentional effort (as measured by pupil dilation) in MI. We evaluated the effects of movement complexity and speed on expert pianists' pupil dilation as they physically executed and used MI to perform easy/complex and slow/fast music phrases. Results revealed that easy movements required similar levels of attentional effort during MI and ME. However, during complex movements performed at a fast speed, the correspondence between execution and imagery of movement was disrupted.     

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 Motor System Computes Well but Remembers Poorly

The psychological approach to human voluntary movements advocated by F. Mechsner (2004) can be aligned with the view that motor commands are generated afresh but are not retrieved from memory. This movement-generation hypothesis gains indirect support in the findings Mechsner reviewed and obtains more direct support from the results of studies of memory for movement and computational modeling of motor planning.     

“Look around while running!” Attentional focus effects in inexperienced runners

While attentional focus effects on running economy have been shown in different settings for trained athletes, it is unclear how attentional instructions should be formulated to improve running economy for inexperienced runners. The present study was designed to fill this gap and test attentional focus effects in runners with little running experience. An experimental design was implemented and participants ran 4 × 6 min at a slow and fixed running pace with different attentional instructions for each block (video, breathing, running movement, no instruction), while oxygen consumption was measured continuously. The results showed best running economy (lowest oxygen consumption) in the video compared with the breathing and movement condition which goes in line with effects for trained runners. Therefore, inexperienced runners can also profit from directing their attention externally and commonly taught principles such as focusing on the coordination of breathing and stride patterns should be reconsidered.     

The memory drum theory after twenty years

The difference between the Henry “memory-drum” theory and our version is that ours includes an additional assumption that, after programming has occurred, the resultant representation can be stored in short-term memory. Otherwise, the essential ideas are the same in the two theories. Implications of the presently available data for the distinction between the theories are discussed. Regardless of how one evaluates our added assumption, it is clear that the essential insight of the Henry theory has fared very well in the 20 yr since the theory first appeared in print.     

Effects of test anxiety on motor learning: The processing efficiency hypothesis

Abstract

The hypothesis that, under test (stress) conditions, high trait-anxious individuals invest extra processing resources to reach motor learning levels similar to those of low-anxious individuals was investigated. A transfer procedure (practice trial, rest interval, and transfer trial) was employed to analyse motor learning effects. In Experiment 1, a secondary task (click detection) was used to measure the extra processing resources expenditure on motor learning during the practice trial. Neither motor performance in the transfer trial nor secondary task performance differed as a function of test condition or anxiety trait. A critical analysis of the secondary task paradigm suggested that it was not sensitive enough to reflect the amount of processing capacity expended on the primary motor tasks. In Experiment 2, subjects performed a loading task (verbal shadowing of sentences) concurrently with the motor tasks during the practice trial to prevent extra resources from being allocated to motor learning. Results showed that anxiety trait was associated to performance time increments on the high-demanding motor tasks in the transfer trial. A plausible explanation is that anxiety impairs learning because it reduces the efficiency of processing. An alternative interpretation, concerning an ability deficit of high trait-anxious individuals, is discussed.     

On the Role of Visual Afferent Information for the Control of Aiming Movements Toward Targets of Different Sizes

The authors investigated (a) whether the specificity of practice hypothesis is mediated by the importance of visual afferent information for the control of manual aiming movements and (b) how movement planning and online correction processes to the movement initial impulse are affected by the withdrawal of visual information in transfer. In acquisition, participants (N = 40) aimed at targets of different sizes in a full-vision or in a target-only condition before being transferred to a target-only condition without knowledge of results. The results supported the hypothesis that learning is specific to the source or sources of afferent information that are more likely to ensure optimal performance. The results also suggested that individuals will not always use visual afferent information more extensively when aiming at a small rather than at a large target. Instead, in a temporally constrained task, the relative efficiency of visually based corrections appears to mediate how exclusively an individual will rely on online visual afferent information for movement control. Finally, the detailed kinematic analysis performed in the present study clearly indicated that online modifications to the movement primary impulse are possible, arguing for a continuous or pseudo-continuous control of relatively slow aiming movements on the basis of visual afferent input.     

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.     

Focusing attention on circular pedaling reduces movement economy in cycling

Previous research has shown that focus of attention affects movement economy in endurance tasks. This experimental study was designed to take a closer look at how focusing attention on special characteristics of endurance cycling actions can influence metabolic energy costs. Twenty-five trained cyclists completed 4 × 6 min time trials at submaximal intensity on a cycling ergometer. For each of the four time trials, they were instructed to adopt a different focus of attention: (1) circular pedaling, (2) force production of quad muscles, (3) head position, (4) stimuli in a cycling video. The order of conditions was counterbalanced. The main dependent measure was movement economy (i.e., oxygen consumption at a given workload). The results show that a focus on the circular pedaling action leads to reduced economy than a focus on the video (p = 0.001). Focusing on smooth and circular pedaling includes a continuous monitoring of the cycling action, which could disturb the rhythmical nature of movement execution, thereby leading to detriments in movement economy.     

Effector Organization and “Gradation” of Effort

It is proposed that an aspect of the effector organization process is the gradation of the response. Gradation was investigated in a hand cranking task by using strain-gauge and electromyographic recording techniques. Criteria of gradation were related to (a) the impulsive force at a particular point in the cycle of movement, (b) an index of the work done per unit of time, (c) the degree of muscle activity in each of the 6 muscles analyzed, and (d) an index of muscle activity based on the pen deflection of an EMG record. Further, two criteria of the organization of the force were employed — the force range and the consistency of the force range. None of the criteria of gradation was closely related to speed of performance, but the organizational criteria showed a trend toward being related to speed. The implications of these findings are discussed.     

特质自我控制对食物线索注意偏向的影响及干预：来自眼动的证据

采用眼动技术,以BMI指数处于正常范围的女性为被试,考察特质自我控制对食物线索注意偏向的影响以及注意偏向训练在改变注意偏向强度上的干预效果。结果发现,对于高热量食物线索,低特质自我控制水平女性表现出了更强的注意偏向;注意偏向训练有效降低了低特质自我控制水平女性对高热量食物线索注意偏向的强度。上述结果表明,特质自我控制影响个体对食物线索的注意偏向,注意偏向训练能有效改变个体对食物线索注意偏向的强度。     

Reducing Knowledge of Results about Relative versus Absolute Timing: Differential Effects on Learning

The purpose of the present experiment was to examine further earlier suggestions that a reduced relative frequency of knowledge of results (KR) can enhance the learning of generalized motor programs (GMPs) but at the same time degrade parameter learning, compared with giving KR after every trial (Wulf & Schmidt, 1989; Wulf, Schmidt, & Deubel, 1993). In contrast to these earlier studies, here KR was given separately for relative timing and absolute timing. Subjects practiced three movement patterns that required the same relative timing but different absolute movement times. KR was provided on 100% or 50% of the practice trials for relative timing or absolute timing, respectively. In retention and transfer tests, the groups that had had 50% KR about relative timing demonstrated more effective learning of the relative-timing structure, that is, GMP learning, than the groups that had had 100% KR about relative timing. The KR frequency had no effect on parameterization during retention; yet, when transfer to a task with a novel overall duration was required, the groups given 100% KR about absolute timing were more accurate in parameterization than the groups provided with 50% KR about absolute timing. Thus, the reduced relative KR frequency enhanced GMP learning but had no beneficial effect, or even a degrading effect, on parameter learning. The differential effects of a reduced KR frequency on the learning of relative timing and absolute timing also provide additional support for the dissociation of GMP and parameterization processes.     

注意觉察系统：实现多任务环境下的人机交互

注意觉察系统是以认知心理学和认知工效学为理论基础设计的、能在多任务环境下帮助用户管理任务中断及转移的新型人机交互系统。本文概述了注意觉察系统的三大功能体系,研究现状,并对这种系统的未来发展趋势作了展望。