Gender-Specific Movement Strategies Using a Computer-Pointing Task

Females typically demonstrate a movement time advantage for tasks requiring high levels of manual dexterity, whereas males are notably better at targeting activities. According to D. Kimura (2000), the hunter-gatherer hypothesis primarily accounts for those performance advantages; that dichotomy fails, however, when one makes movement outcome predictions for tasks that are not clearly fine-motor or interceptive in nature. Investigators have recently proposed that time constraints (M. Peters, 2005) and gender-specific response style differences (M. Peters & P. Campagnaro, 1996; L. E. Rohr, 2006) affect motor performance. Here, the author used a computer-pointing task measuring both movement error and movement time in 16 participants to further investigate response style differences. Kinematic and linear regression analyses between resultant error and both movement time and task difficulty reinforced the notion that gender-specific movement biases emphasize speed and accuracy, respectively, for men and women.     

Movement Control Strategies in a Dynamic Balance Task in Children With and Without Developmental Coordination Disorder

Abstract

Our study aimed to analyze movement control strategies using predefined criteria for amplitude and differences in these strategies between children with and without DCD. Children with (n?=?28) and without DCD (n?=?15) were included. A video-observation-tool was used to score the moving body parts during a Wii Fit slalom task over multiple time points. Two-step cluster analysis was used to extract distinct movement strategies. Two different movement strategies were identified that were independently validated by a measure of task performance and a subjective mark of quality of the movement. Initial differences between groups and changes over time toward the more successful strategy were found in both groups, albeit in a different percentage. This study shows that the more efficient movement strategy is seen in the majority of the TD children and only in a small number of children with DCD, even after practice.     

Error Detection and Correction in a Structured Movement Task

Error-detection and error-correction experiments were conducted to examine the assumption that organizational processes play an important role in motor learning and control. During the initial phase of each experiment, the sensory aspects of five movements were held constant while the organizational structure (sequential vs. random) of the movements was varied. In the learning phase of both experiments, the effect of organization produced increased reproduction accuracy for the structured movement sequences compared to those that were random. This benefit of organization carried over into the error detection and correction parts of the experiments where it was shown that improved error detection and correction capabilities were assisted by the manner in which the movements were presented. The importance of cognitive processes is discussed in terms of past and contemporary accounts of motor learning and control.     

The Activity-Set Hypothesis for Warm-up Decrement in a Movement Balance Task

This study investigated the activity-set hypothesis in reducing warm-up decrement. With regard to the hypothesis, it is predicted that warm-up decrement, which is a temporary loss of skill performance following rest, could be reduced if an appropriate reinstating activity were engaged in just prior to the resumption of practice. Seventyfive subjects were given twenty 20-sec tests on the stabilometer (criterion task), and then either (a) rested, (b) rested and then performed on interpolated “activity-set” task, or (c) rested and then performed an interpolated “activation” task. All subjects, after receiving one of the three conditions were then retested on the stabilometer for an additional six trials. An analysis of planned comparisons showed that the activity-set interpolated task was effective in reducing warmup decrement and that activation was not a factor.     

延迟命名任务中图词干扰效应的眼动研究

采用图-词分离呈现及眼动技术探讨在延时命名条件下图-词干扰效应发生的位置。结果发现：（1）延时命名图片时,仍出现图-词干扰效应和频率效应;（2）与命名干扰词相比,命名图片时图片的回视率高,注视时间长;（3）图片的注视时间也出现频率效应和图-词干扰效应。这说明即使在延时命名图片的条件下,目标词汇仍需要再次激活,频率效应和图-词干扰效应是发生在词汇化过程中,反驳反应排除理论的图-词干扰反应选择阶段的观点,支持了词汇化选择竞争的理论。     

Effects of Auditory Feedback on Movement Time in a Fitts Task

The purpose of the present experiment was to investigate the role of auditory feedback and its impact on movement time in a standard Fitts task. Feedback was given at the moment of target acquisition. A 2-way analysis of variance found significant differences between feedback groups at all three indexes of difficulty (F(2, 40) = 156.02, p < .001). Results from a mixed-model multivariate analysis of variance for kinematic factors show significant differences in peak velocity and the location of peak velocity when comparing feedback groups. In general, the addition of auditory feedback decreased the task ID by .5.     

The Sequential Structure of Movement Outcome in Learning a Discrete Timing Task

The sequential structure of discrete movement outcomes in an elbow-flexion movement task was examined with a crossed design of 2 movement-time (125 and 500 ms) and 2 range-of-motion (5 degrees and 20 degrees ) conditions over sets of 200 trials of practice. Traditional analyses of error score. techniques, time-series analyses of the quantitative raw and differenced data, and a symbolic dynamic analysis of qualitative events arising from the data were conducted. The differenced data revealed a consistent order over 3-trial strings that was more apparent with larger steps in the data scores, but quantitative time-series and symbolic dynamic analyses of the raw movement-time data showed weaker relations. There were a few patterns of structure evident in the raw data time series that were a function of the movement condition and the skill level of the subject. The analyses of the movement-time scores revealed that, in learning the discrete timing task, there is more order apparent in the intrinsic frame of reference of the difference scores than in the extrinsic frame of reference.     

One-Handed Juggling: A Dynamical Approach to a Rhythmic Movement Task

The skill of rhythmically juggling a ball on a racket was investigated from the viewpoint of nonlinear dynamics. The difference equations that model the dynamical system were analyzed by means of local and nonlocal stability analyses. These analyses showed that the task dynamics offer an economical juggling pattern that is stable even for open-loop actuator motion. For this pattern, two types of predictions were extracted: (a) Stable periodic bouncing is sufficiently characterized by a negative acceleration of the racket at the moment of impact with the ball, and (b) a nonlinear scaling relation maps different juggling trajectories onto one topologically equivalent dynamical system. The relevance of these results for the human control of action was evaluated in an experiment in which subjects (N = 6) performed a comparable task of juggling a ball on a paddle. Task manipulations involved different juggling heights and gravity conditions of the ball. The following predictions were confirmed: (a) For stable rhythmic performance, the paddle's acceleration at impact is negative and fluctuations of the impact acceleration follow predictions from global stability analysis; and (b) for each subject, the realizations of juggling for the different experimental conditions are related by the scaling relation. These results permit one to conclude that humans reliably exploit the stable solutions inherent to the dynamics of the given task and do not overrule these dynamics by other control mechanisms. The dynamical scaling serves as an efficient principle for generating different movement realizations from only a few parameter changes and is discussed as a dynamical formalization of the principle of motor equivalence.     

Subjective Estimation of Task Time and Task Difficulty of Simple Movement Tasks

It has been demonstrated in previous work that the same neural structures are used for both imagined and real movements. To provide a strong test of the similarity of imagined and actual movement times, 4 simple movement tasks were used to determine the relationship between estimated task time and actual movement time. The tasks were single-component visually controlled movements, 2-component visually controlled, low index of difficulty (ID) moves and pin-to-hole transfer movements. For each task there was good correspondence between the mean estimated times and actual movement times. In all cases, the same factors determined the actual and estimated movement times: the amplitudes of movement and the IDs of the component movements, however the contribution of each of these variables differed for the imagined and real tasks. Generally, the standard deviations of the estimated times were linearly related to the estimated time values. Overall, the data provide strong evidence for the same neural structures being used for both imagined and actual movements.     

Search Strategies in Practice: Movement Variability Affords Perception of Task Dynamics

Practice has been conceptualized in terms of a search process through an evolving perceptual-motor workspace. The experiment was set up to examine whether the inherent variability of the system would influence perception of the relevant properties of the task space. We reanalyzed the data from Hsieh, Liu, Mayer-Kress, and Newell (2013) in which participants performed a speed-accuracy aiming task and feedback emphasized either temporal or spatial accuracy in different conditions. The maximum variability in spatial error during practice differentiated individual's best performance in the fast speed-accuracy conditions. Additionally, we found that a threshold of variability predicted discontinuities during practice within individuals. The findings support the proposition that inherent variability affords perception of the relevant dimension of the task. The search motion through the perceptual-motor workspace was continuous or discontinuous depending on the constraints of the movement speed-accuracy condition.     

The Stationary-Gaze Task Should Not Be Systematically Used as the Control Task in Studies of Postural Control

In studies of postural control, a control task is often used to understand significant effects obtained with experimental manipulations. This task should be the easiest task and (therefore) engage the lowest behavioral variability and cognitive workload. Since 1983, the stationary-gaze task is considered as the most relevant control task. Instead, the authors expected that free looking at small targets (white paper or images; visual angle: 12°) could be an easier task. To verify this assumption, 16 young individuals performed stationary-gaze, white-panel, and free-viewing 12° tasks in steady and relaxed stances. The stationary-gaze task led to significantly higher cognitive workload (mean score in the National Aeronotics and Space Administration Task Load Index questionnaire), higher interindividual body (head, neck, and lower back) linear variability, and higher interindividual body angular variability—not systematically yet—than both other tasks. There was more cognitive workload in steady than relaxed stances. The authors also tested if a free-viewing 24° task could lead to greater angular displacement, and hence greater body sway, than could the other tasks in relaxed stance. Unexpectedly, the participants mostly moved their eyes and not their body in this task. In the discussion, the authors explain why the stationary-gaze task may not be an ideal control task and how to choose this neutral task.     

搞好哮喘控制是一项长期而艰巨的任务

哮喘在全世界是一个严重的公共卫生问题.当哮喘未控制时,哮喘可以影响患者的日常生活质量,甚至可以致命.搞好哮喘控制工作是一项长期而艰巨的任务,在实际工作中应推广以"哮喘临床控制"为核心的哮喘治疗循环模式,即评估患者的哮喘控制水平、治疗并达到哮喘控制、监测并维持哮喘控制.     

Effects of S-R Compatibility and Task Difficulty on Unimaimual Movement Time

Using a system in which S controlled a cursor on an oscilloscope screen by moving a lever, the S-R relationship on either hand could be reversed. This system was used in two experiments designed to investigate the effect on unimanual movement time of varying S-R compatibility, and task difficulty as defined by Fitts (1954). The results indicated the necessity of specifying task difficulty in an investigation of S-R compatibility. Further, it was found that as task difficulty increased the difference in performance between the right and left hands became more marked.     

眼动交互中边框和视标对作业绩效的影响研究

研究人计算机界面设计中的眼动交互反馈方式,为优化基于视线追踪技术的人计算机界面设计提供工效学依据。12名被试在交互对象有无边框提示和当前注视位置有无视标反馈的四种组合条件下,通过眼动交互完成目标选择任务,由计算机自动记录作业时间、选择错误和超时数目。结果发现,有无当前注视位置的视标反馈对作业时间有显著影响,有视标反馈可加速目标字母的搜索与定位过程和目标激活过程,由视标反馈所产生的作业时间下降,主要由目标定位时间的缩短所致;边框提示对用户的作业绩效无显著影响。根据上述结果可得以下结论:对当前注视位置提供视标反馈是一种有效的反馈方式,基于视线追踪的人机交互系统应为用户提供这种反馈信息。     

搞好哮喘控制是一项长期而艰巨的任务

哮喘在全世界是一个严重的公共卫生问题。当哮喘未控制时,哮喘可以影响患者的日常生活质量,甚至可以致命。搞好哮喘控制工作是一项长期而艰巨的任务,在实际工作中应推广以“哮喘临床控制”为核心的哮喘治疗循环模式,即评估患者的哮喘控制水平、治疗并达到哮喘控制、监测并维持哮喘控制。     

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.     

Reciprocal Effects Between Locus of Control and Job Attributes

The purpose of this study was to examine the reciprocal relationships between locus of control and job attributes of a representative sample of 1383 employees in a large Australian city. It was predicted that employees with an internal locus of control would attain jobs higher on skill-utilization, influence and income than those attained by employees with an external locus of control. It was also predicted that jobs involving high skill-utlization, influence and income would induce greater internal control beliefs than those low on skill-utilization, influence and income. Locus of control was measured using Rotter's scale (Rotter, 1966). Reciprocal causation was assessed using two-stage least squares analysis. For the total sample, it was found that locus of control and job attributes were reciprocally determined. However, locus of control was not related to influence when skill-utilization and income were controlled. When the sample was split on the basis of gender and marital status, the predicted relationships between locus of control, skill-utilization and income were found for married men only. For married women, locus of control was neither a determinant of job attributes nor an outcome of job experience. These sub-group differences were interpreted in terms of differences in job tenure, work values and occupational opportunity.     

基于多Agent的运动图像匹配任务分配策略研究

本文针对基于多Agent的运动图像匹配系统的任务分配策略进行了讨论,并结合遗传算法和模拟退火算法给出了一种新的基于多Agent的运动图像模式匹配系统的任务分配策略。     

Staging Reciprocal Metaphors in a Couples Group

This paper describes an approach to couples therapy based on defining the reciprocal positions of each spouse in relation to a central theme. These positions and the theme around which they are organized are crystallized into visible forms through staged metaphors. When studied in relation to one another, the metaphors provide a holistic view of the relationship and are used as an artifice for change.     

靶子-靶子任务中认知控制对返回抑制的反转

使用冲突色词作为外源性线索,通过3(任务类型)×2(线索有效性)×2(色词一致性)混合设计考察认知控制对返回抑制(IOR)的影响。结果:(1)线索-靶子任务(CT)和靶子-靶子任务(TT)均产生正值IOR,CT的IOR效应量(32ms)显著大于TT(12ms)。(2)线索有效性和任务类型交互作用显著。按键反应组IOR效应量(11.85ms)显著大于颜色反应组(-18.5ms)和词意反应组(-25.65ms)。证实冲突色词在CT任务中做为线索可产生IOR,这种范式上的新尝试同样适用于TT任务。在TT任务中对认知冲突的觉察和控制导致IOR效应反转,支持注意的非盲性机制。研究为主动操纵被试对线索的认知控制程度,考察复杂任务下实施认知控制对注意定向的影响提供了一条可行途径。