Impact of Handedness Consistency on Bimanual and Unimanual Continuous Movements

Bimanual coordination is an essential human function requiring efficient interhemispheric communication to produce coordinated movements. Previous research suggests a “bimanual advantage” phenomenon, where completing synchronized bimanual tasks results in less variability than unimanual tasks. Additionally, of hand dominance has been shown to influence coordinated performance. The present study examined the bimanual advantage in individuals with consistent and inconsistent handedness. It was predicted that participants with consistent handedness would not display a bimanual advantage unlike those with inconsistent handedness. Fifty-six young adults completed a finger-tapping paradigm in five conditions: unimanual tapping with either left or right hand, in-phase bimanual tapping, and out-of phase bimanual tapping led by either left or right hand. Results were not consistent with the hypothesis that participants with consistent handedness displayed the “bimanual advantage”. However, the “bimanual advantage” was not evident for the inconsistent handers when the temporal consistency was measured with either the left or right hand only. Overall, the “bimanual advantage” may be dependent upon consistency of hand preference, as well as the direction of hand dominance.     

A social-psychological perspective on tacit coordination: How it works,when it works, (and when it does not)

We present a programmatic line of experimental studies which focus on the how and when of tacit coordination (i.e., the phenomenon that people can successfully coordinate their decisions without communication). We investigated this phenomenon using different types of economic games (i.e., social dilemmas as well as coordination games). Our studies broadly cover three themes: (a) fairness as a coordination rule, (b) uncertainty and common understanding, (c) social information as a cue. By focusing on these themes we have obtained several new insights on the prerequisites and boundary conditions of tacit coordination. We conclude that tacit coordination is often facilitated by mutual adherence to social norms (e.g., fairness rules, rules of deference, etcetera), but that in order to employ such norms people need sufficient environmental and/or social information.     

Organization of Compensatory Postural Coordination Patterns

The authors investigated whether compensatory postural coordination patterns are organized according to the same dynamical principles as are nonequilibrium phase transitions. Eight participants were asked to maintain upright balance on a moving platform that was sinusoidally translated in the anterior-posterior direction and was systematically increased and decreased 0.19 Hz as a step function every 10 platform cycles through the frequency range 0.19–1.46 Hz. At low platform frequencies, all participants exhibited small joint angular motions with high variability, and the relative phase between the joint motions exhibited drifting patterns and large fluctuations. As platform frequency increased, the amplitude of joint motion increased systematically and joint-specific oscillatory patterns emerged. The findings provided no evidence for a Hopf bifurcation or hysteresis in the transitions of postural coordination modes, however, or, mote generally, a basis for distinguishing the relevance of linear versus nonlinear models of postural control.     

Intelligence and Extraversion in the neural evaluation of delayed rewards

Temporal discounting (TD), the preference for earlier, smaller rewards over delayed, larger rewards, is a pervasive phenomenon that covaries with Big Five personality traits and Intelligence (IQ). This study provides novel insight by identifying correlates for IQ and Extraversion in the neural representation of TD preferences. An intertemporal choice task was employed, where offers were sequentially presented, distinguishing between one evaluation phase (first offer is presented) and one comparison phase (second offer is presented and values are compared). IQ correlated with responses of caudate nucleus to the subjective values of the offers, suggesting a role of cognitive abilities in modulating reward responses. Extraversion correlated with the strength of functional connectivity of a reward evaluation network centered on ventromedial prefrontal cortex.     

Developmental dyspraxia and developmental coordination disorder

This article discusses the role developmental dyspraxia plays in developmental coordination disorder (DCD), based upon a review of literature on apraxia, developmental dyspraxia, and DCD. Apraxia and dyspraxia have often been equated with DCD. However, it is argued that apraxia and dyspraxia primarily refer to the problems of motor sequencing and selection, which not all children with DCD exhibit. The author proposes to distinguish developmental dyspraxia from DCD. Other issues discussed include the assessment, etiology, and treatment of developmental dyspraxia and DCD, and the relationship between DCD and learning disabilities. A research agenda is offered regarding future directions to overcome current limitation.     

软件开发组织的沟通与协调

在对软件开发中人员与组织问题进行回顾的基础上,该文首先就软件开发组织沟通与协调的重要性进行分析,然后对软件开发组织中的沟通与团队结构、沟通与项目成员、沟通频次分布、沟通方式等问题,以及整体协调、外部协调、内部协调等问题进行阐述。最后就今后软件开发组织沟通与协调问题可拓展的研究方向进行了讨论。     

Understanding Cognition Through Large-Scale Cortical Networks

An emerging body of evidence from a number of fields is beginning to reveal general neural principles underlying cognition. The characteristic adaptability of cognitive function is seen to derive from large-scale networks in the cerebral cortex that are able to repeatedly change the state of coordination among their constituent areas on a subsecond time scale. Experimental and theoretical studies suggest that large-scale network dynamics operate in a metastable regime in which the interdependence of cortical areas is balanced between integrating and segregating activities. Cortical areas, through their coordination dynamics, are thought to rapidly resolve a large number of mutually imposed constraints, leading to consistent local states and a globally coherent state of cognition.     

Towards a broader scope of biomechanics in developmental studies: a commentary on Jensen (2005)

In this article, we discuss where biomechanical analysis can contribute to our understanding of motor development, and more particularly in what ways biomechanics can contribute to (1) explaining the universal sequence in motor milestones; (2) explaining variations in developmental sequence between individuals; (3) understanding the impact of context on the actions of an individual; and (4) understanding, preventing, and managing chronic disabilities. In our view, biomechanics is concerned with the dynamics of the musculo‐skeletal system (MSS) and thus provides insights in the way motion is affected by the activation of muscles and the mechanical interaction between the MSS and the environment. Biomechanical analysis is important in understanding the development of actions that depend on the perceptual‐motor loop although it cannot provide a full account of the changes in the behaviour. The contributions and limitations of specific biomechanical analyses such as the inverse and forward dynamical models are discussed in the light of the article of Jensen (2005). Copyright © 2005 John Wiley & Sons, Ltd.     

The effects of expectancy on inhibition of return

This research examined the influence of cue temporal predictability on inhibition of return (IOR). In exogenous attention experiments, the cue that summons attention is non-informative as to where the target will appear. However, it is predictive as to when it will appear. Because in most experiments there are equal numbers of trials for each cue-target interval (SOA--stimulus onset asynchrony), as time passes from the appearance of the cue, the probability of target presentation increases. Predictability was manipulated by using three SOA distributions: non-aging, aging and accelerated-aging. A robust IOR was found that was not modulated by temporal information within a trial. These results show that reflexive effects are relatively protected against modulation by higher volitional processes.