The effect of force-controlled biting on human posture control

Several studies have confirmed the neuromuscular effects of jaw motor activity on the postural stability of humans, but the mechanisms of functional coupling of the craniomandibular system (CMS) with human posture are not yet fully understood. The purpose of our study was, therefore, to investigate whether submaximum biting affects the kinematics of the ankle, knee, and hip joints and the electromyographic (EMG) activity of the leg muscles during bipedal narrow stance and single-leg stance. Twelve healthy young subjects performed force-controlled biting (FB) and non-biting (NB) during bipedal narrow stance and single-leg stance. To investigate the effects of FB on the angles of the hip, knee, and ankle joints, a 3D motion-capture system (Vicon MX) was used. EMG activity was recorded to enable analysis of the coefficient of variation of the muscle co-contraction ratios (CVR) of six pairs of postural muscles. Between FB and NB, no significant differences were found for the mean values of the angles of the ankle, knee, and hip joints, but the standard deviations were significantly reduced during FB. The values of the ranges of motion and the mean angular velocities for the three joints studied revealed significant reduction during FB also. CVR was also significantly reduced during FB for five of the six muscle pairs studied. Although submaximum biting does not change the basic strategy of posture control, it affects neuromuscular co-contraction patterns, resulting in increased kinematic precision.     

Motor imagery ability and internal representation of movement in children with probable developmental coordination disorder

It has been hypothesised that deficits in the functioning of the mirror neuron system (MNS) and internal modelling may contribute to the motor impairments associated with DCD. These processes can be explored behaviourally through motor imagery paradigms. Motor imagery proficiency of children with and without probable DCD (pDCD) was examined using a complex hand rotation task to explore whether motor imagery strategies could be used during more complex tasks. Forty-four boys aged 7–13 years participated, 22 with pDCD (mean = 9.90 years ± 1.57) and 22 controls (mean = 9.68 years ± 1.53). Participants completed the task twice: with and without motor imagery instructions. Stimuli were presented in two rotational axes – palm/back, and eight 45° rotational steps. Both groups showed evidence of following the biomechanical and postural constraints of actual movements. Responses of children with pDCD were slower and less accurate than controls, with group differences increasing alongside task complexity. A greater impact of biomechanical constraints for accuracy was observed in the DCD group. The response characteristics of children with pDCD likely reflects a reduced capacity to mentally manipulate a body schema and reduced visuo-motor processing capabilities. Behaviourally, these processes are linked to MNS and internal modelling function, suggesting deficits in these systems may contribute to the movement difficulties characteristic of DCD.     

Procedural learning and automatization process in children with developmental coordination disorder and/or developmental dyslexia

ObjectiveThere is increasing evidence to suggest that developmental dyslexia (DD) and developmental coordination disorder (DCD) actually form part of a broader disorder. Their frequent association could be justified by a deficit of the procedural memory system, that subtends many of the cognitive, motor and linguistic abilities that are impaired in both DD and DCD. However, studies of procedural learning in these two disorders have yielded divergent results, and in any case no studies have so far addressed the issue of automatization (dual-task paradigm).MethodsWe administered a finger tapping task to participants aged 8–12 years (19 DCD, 18 DD, and 22 with both DD and DCD) to explore procedural learning and automatic movements in these three groups of children, comparing motor performances at the prelearning stage, after 2 weeks of training, and in a post-training dual-task condition.ResultsFirst, results indicated that all the children were able to learn a sequence of movements and even automatize their movements. Second, they revealed between-groups differences in procedural/automatization learning abilities, setting the DCD group apart from the other two. Third, contrary to our expectations concerning comorbidity, they suggested that the DD + DCD association does not have an additional impact on behavioral performances.     

Pluralism and values in education in Hungary – changes between 1990 and 2012

Value transmission is a fundamental task of schools. However, the question arises as to how far prevailing political and social conditions shape the functioning of a country or a region’s school system. In other words: what effect do they have on the choice of values to be transmitted at schools? Are there any fundamental social values that are shared by different cultures at different times? Are there values that exist independently of social and political systems? These questions have a special relevance in Eastern and Central European countries like Hungary where political and social changes in the twentieth century had a crucial effect on the set of values that were transmitted by the school system. The aim of this study is to describe how the value transmitting role of the Hungarian school system has changed as a consequence of political transformations in recent decades.     

Diversity and unity of modularity

Since the publication of Fodor's (1983) The Modularity of Mind, there have been quite a few discussions of cognitive modularity among cognitive scientists. Generally, in those discussions, modularity means a property of specialized cognitive processes or a domain-specific body of information. In actuality, scholars understand modularity in many different ways. Different characterizations of modularity and modules were proposed and discussed, but they created misunderstanding and confusion. In this article, I classified and analyzed different approaches to modularity and argued for the unity of modularity. Modularity is a multidimensional property consisting of features from several dimensions specifying different aspects of cognition. Among those, there are core features of modularity, and these core features form a cross-dimensional unity. Despite the diverse and liberal characterizations, modularity contributes to cognitive science because of the unity of the core features.     

Procedural fairness and endorsement of prototypical leaders: Leader benevolence or follower control?

This research explored why strongly identifying followers endorse prototypical leaders by addressing the role of procedural fairness in this process. We introduced the distinction between procedural fairness rules relating to leader benevolence (i.e., whether the leader supports the group’s interests) and follower control (i.e., whether followers can influence the leader’s decisions). We predicted that strongly identifying group members endorse prototypical leaders because they perceive such leaders as acting in line with benevolence related fairness rules rather than because such leaders are perceived as giving followers control. An organizational field study and a laboratory experiment revealed support for these ideas. Our results thus provide insights into why prototypical leaders are endorsed among strongly identifying followers. They also have implications for the procedural fairness literature in showing that frequently studied procedural fairness rules (e.g., voice) do not explain endorsement of leaders believed to support the group’s interests.     

消化内镜医师培训的现状及计算机模拟训练系统的应用

传统的以患者为基础的消化内镜医师培养模式已不能适应消化内镜的快速发展和病患对内镜操作技术的高要求,通过多媒体和虚拟现实技术建立的计算机辅助的内镜模拟训练系统相对于传统的消化内镜医师培训方式是一个巨大进步,它能帮助初学者较快掌握消化内镜诊疗操作的基本技能,使各级消化内镜培训中心的规范化教学成为可能.但是,模拟内镜训练必须结合实际病例的操作才能巩固从模拟内镜得到的内镜操作技能.本文总结了目前消化内镜医师培训的现状,重点对消化内镜模拟训练系统在内镜医师培训中的作用和存在的问题进行探讨,并提出了自己的观点.