Variability and Determinism in Motor Behavior

In investigations into perception-action systems, variability of observable behavior may be considered to (a) interfere with inquiry, (b) be neither detrimental nor particularly useful to inquiry, or (c) play a crucial role in inquiry. The authors underscore recent suggestions that alternative (c) is a preferred strategy for the study of many motor behaviors. In tutorial fashion, the authors review the concepts of variability and determinism with respect to postural and rhythmic movements. Study of the variability of those behaviors has revealed crucial features suggestive of underlying mechanisms and control, such as particular blends of noise and determinism (piecewise determinism). It has also revealed general lessons (for example, more variable does not mean more random and more controllable does not mean more deterministic) that may extend to other classes of perceptual-motor behavior.     

Modular Organization of Exploratory Force Development Under Isometric Conditions in the Human Arm

Muscle coordination of isometric force production can be explained by a smaller number of modules. Variability in force output, however, is higher during exploratory/transient force development phases than force maintenance phase, and it is not clear whether the same modular structure underlies both phases. In this study, eight neurologically-intact adults isometrically performed target force matches in 54 directions at hands, and electromyographic (EMG) data from eight muscles were parsed into four sequential phases. Despite the varying degree of motor complexity across phases (significant between-phase differences in EMG-force correlation, angular errors, and between-force correlations), the number/composition of motor modules were found equivalent across phases, suggesting that the CNS systematically modulated activation of the same set of motor modules throughout sequential force development.     

Effect of Concurrent Visual Feedback Frequency on Postural Control Learning in Adolescents

The purpose was to find better augmented visual feedback frequency (100% or 67%) for learning a balance task in adolescents. Thirty subjects were divided randomly into a control group, and 100% and 67% feedback groups. The three groups performed pretest (3 trials), practice (12 trials), posttest (3 trials) and retention (3 trials, 24 hours later). The reduced feedback group showed lower RMS in the posttest than in the pretest (p = 0.04). The control and reduced feedback groups showed significant lower median frequency in the posttest than in the pretest (p < 0.05). Both feedback groups showed lower values in retention than in the pretest (p < 0.05). Even when the effect of feedback frequency could not be detected in motor learning, 67% of the feedback was recommended for motor adaptation.     

Noninvasive brain stimulation over M1 and DLPFC cortex enhances the learning of bimanual isometric force control

Motor learning plays an important role in upper-limb function and the recovery of lost functionality. This study aimed to investigate the relative impact of transcranial direct current stimulation (tDCS) on learning in relation to the left primary motor cortex (M1) and left dorsolateral prefrontal cortex (DLPFC) during bimanual isometric force-control tasks performed with both hands under different task constraints. In a single-blind cross-over design, 20 right-handed participants were randomly assigned to either the M1 group (n = 10; mean age, 22.90 ± 1.66 years, mean ± standard deviation) or the DLPFC group (n = 10; mean age, 23.20 ± 1.54 years). Each participant received 30 min of tDCS (anodal or sham, applied randomly in two experiments) while performing the bimanual force control tasks. Anodal tDCS of the M1 improved the accuracy of maintenance and rhythmic alteration of force tasks, while anodal tDCS of the DLPFC improved only the maintenance of the force control tasks compared with sham tDCS. Hence, tDCS over the left M1 and DLPFC has a beneficial effect on the learning of bimanual force control.     

定量运动负荷后间隔不同时间的肘关节动觉方位准确性

该研究以过去研究中发现的定量运动负荷可以显著提高肘关节动觉方位准确性为基础,试图讨论这种定量运动负荷后间隔不同时间的肘关节动觉方位准确性。     

注视方向的知觉对注视追随行为的影响

他人的注视线索可诱导观察者将注意自动地转移到该线索所指示的方向上去(注视追随), 但仍不清楚注视方向的知觉在注视追随中起到何种作用。本研究结合注视适应和注视线索提示范式发现：知觉到的注视线索角度越大, 其线索提示效应越强; 知觉适应后被试判断注视方向的准确性下降, 注视线索引起的注意转移量显著减少。可见, 对注视方向的知觉能直接影响注视追随行为, 而注视方向抽取受到刺激显著性(注视角度)和知觉适应等因素的调节。这提示：在意识状态下, 注视知觉与注视追随存在直接联系, 即可能存在从注视知觉系统到注意转移系统的皮层加工通路; 注视追随并非纯粹的反射式加工, 它受自上而下知觉经验的调节。     

Adapting Parent–Child Interaction Therapy for Deaf Families That Communicate via American Sign Language: A Formal Adaptation Approach

While our field has made positive strides in adapting psychotherapeutic interventions for diverse groups of people, considerable work is still needed in this area. We present our formal adaptation procedure for parent–child interaction therapy (PCIT) with Deaf persons. This includes a review of the cultural adaptation process for psychological interventions, including PCIT, as well as an introduction to Deaf culture. Details regarding the specific adaptation of PCIT for Deaf persons are outlined. We found that the utilization of a clear framework to guide the cultural adaptation process facilitated careful consideration of the numerous linguistic and cultural variables involved, while maintaining integrity of the treatment model. While the current focus was on adapting PCIT for Deaf families who communicate via American Sign Language, this framework can also be applied to other populations and/or interventions.     

The psychological adjustment of young immigrants in Norway

In order to examine the adjustment of young immigrants to their new cultural environment, questionnaires were administered to young Third World immigrants living in Norway. Responses (N = 568) obtained from these children aged 10 through 17 years old, indicated that even though they evaluated their health and present life as satisfactory, a good deal of low self-image, depressive tendencies and psychological and somatic symptoms were present among them. Approximately between 11 and 14% of the children were found to have from high to extreme levels of symptomatology. Anti-social behaviors were on the other hand almost entirely absent among the sample, a situation believed to be an artifact of the measuring instrument used. While no differences were observed between boys and girls with respect to how they evaluated their health and present life, girls were found to report more disorders than boys. Boys on the other hand reported engaging in more anti-social behaviours than girls. Using Norwegians of similar age as a reference group, these children were found to be worse off than their native peers. The children's psychological disorders were found to be related to their mode of acculturation, and that integration may be the most adaptive mode of acculturation.     

反馈类型和反馈时间对动作技能获得的影响

基于简单直线运动任务和复杂曲线追踪任务,在运动技能获得阶段考察不同反馈类型和反馈时间对操作绩效的影响。结果发现,在复杂曲线轨迹追踪任务中,接受运动轨迹反馈的被试组比接受偏差数值反馈组的成绩更好;即时反馈和延迟反馈组的操作绩效间没有显著差异。在简单直线运动任务中,提供落点偏差的图形反馈组成绩始终优于提供“近/远”信息的文本反馈组;在练习初期,即时反馈组成绩更好。说明,反馈信息的具体-抽象程度影响被试运动技能获得,提供具体直观的轨迹/图形反馈利于运动技能获得;反馈时间对运动技能的影响因任务难度而异。     

身体动作与语义加工:具身隐喻的视角

概念隐喻理论认为个体建立基于身体经验的具体概念和抽象概念之间的隐喻联结是人类特有的认知方式。不管是具体概念还是抽象概念,只要有具身隐喻联结的概念,其语义的理解便会受到具身启动效应的影响。大脑在加工动词或者含动词的句子时,不仅激活了语言中枢和运动皮层,且大脑随着个体是否执行与语义相应的动作、抽象概念的熟悉程度和其文本背景是否符合等因素而激活不同的神经回路。本文将对以上研究进行梳理与分析,旨在从具身隐喻的视角为身体动作影响语义加工的神经机制模型提供初步的思路。