Self-reported walking difficulty and knee osteoarthritis influences limb dynamics and muscle co-contraction during gait

Knee osteoarthritis (OA) gait is characterized by simultaneous flexor and extensor use, or co-contraction. Co-contraction can stabilize and redirect joint forces. However, co-contraction can push and pull on the femur and tibia that exacerbate OA symptoms and make walking difficult. Such movements are quantifiable by limb dynamics (i.e., linear acceleration and jerk); thus, this study examines limb dynamics and its relationship with co-contraction and OA related walking difficulty.Three groups of age-and-sex-matched subjects with and without OA and walking difficulty (N = 13 per group) walked with electromyography (EMG) on the knee extensors and flexors and inertial measurement units (IMUs) at the femur and tibia. We calculated co-contraction from antagonistic EMG signals and linear acceleration and its derivative jerk from IMUs. We determined group differences using one-way ANOVAs, nonparametric equivalence, and effect sizes, and main and interaction effects of walking difficulty with regression modeling.Medium effect sizes and differences for femoral acceleration (d = 0.64; P = .02) and jerk (d = 0.51; P = .01) were observed between with and without knee OA. Medium to large effect sizes (r = 0.33 to 0.51 and d = 0.81 to 0.97) and differences (P = .01 to 0.05) for tibial acceleration and jerk were obsevered between with and without walking difficulty. Walking difficulty moderated the relationship between tibial jerk and co-contraction (p < .05).Tibial jerk differences were observed based on walking difficulty. The significant interaction effect suggested that walking difficulty explained the relationship between limb dynamics and co-contraction. Perhaps co-contraction levels used by those with knee OA and no walking difficulty are optimal as compared to those with walking difficulty.     

La résilience et le bien-être psychologique au travail au service de la thèse du travailleur heureux-productif

Based on broaden-and-build theory, this study proposes to expand the happy-productive worker thesis by exploring an emergent operationalization of happiness. To do so, the mediating effect of the dimensions of psychological well-being at work (i.e., relation to oneself, to others and to work) on the relation between resilience and task performance has been tested. A total of 280 Quebec workers filled out validated measures. Obtained by structural equation modelling analyses, the results indicate that the rapport with oneself of psychological well-being at work acts as the only mediator between resilience and task performance. These findings underscore the importance of encouraging the development of interventions that build on the resilience and positive experience of workers to optimize their work performance.     

权力对延迟选择的影响

本研究旨在考察权力对延迟选择的影响, 并探讨决策难度在其中的调节作用以及决策过程的中介作用。两个实验均先操纵个体的权力状态, 然后再请被试完成随后的延迟选择任务。结果发现, 决策难度可调节权力对延迟选择的影响, 当决策困难时, 高权力者具有更低的延迟倾向, 当决策容易时, 权力的影响消失。决策过程的加工变异性可中介权力对延迟选择的影响。结果表明, 低权力者比高权力者具有更高的延迟倾向(尤其当决策困难时), 不同权力水平者在决策过程上的差异或可部分解释此种现象。     

A computational analysis of general intelligence tests for evaluating cognitive development

The progression in several cognitive tests for the same subjects at different ages provides valuable information about their cognitive development. One question that has caught recent interest is whether the same approach can be used to assess the cognitive development of artificial systems. In particular, can we assess whether the ‘fluid’ or ‘crystallised’ intelligence of an artificial cognitive system is changing during its cognitive development as a result of acquiring more concepts? In this paper, we address several IQ tests problems (odd-one-out problems, Raven’s Progressive Matrices and Thurstone’s letter series) with a general learning system that is not particularly designed on purpose to solve intelligence tests. The goal is to better understand the role of the basic cognitive operational constructs (such as identity, difference, order, counting, logic, etc.) that are needed to solve these intelligence test problems and serve as a proof-of-concept for evaluation in other developmental problems. From here, we gain some insights into the characteristics and usefulness of these tests and how careful we need to be when applying human test problems to assess the abilities and cognitive development of robots and other artificial cognitive systems.     

威胁性刺激注意偏向的时间进程

注意偏向各成分间关系及发生时间进程尚存争议。本研究以情绪图片为刺激,采用类别判断任务,通过眼动技术探讨正常个体对威胁性刺激注意偏向的时间进程。结果显示,(1)向左的首次眼跳概率高于向右,而潜伏期短于向右,存在左侧偏向;(2)注意回避发生在250ms以内,解除锁定困难发生在400ms之后;(3)注意偏向影响类别判断过程。结果表明,注意回避与左侧偏向在威胁性刺激注意偏向形成早期存在相互作用,且比解除锁定困难更早发生。     

Motor actions and spatiotemporal changes by weight divisions of mixed martial arts: Applications for training

This study compared motor actions and spatiotemporal changes between weight divisions from Ultimate Fighting Championship (UFC™), conducting a practical application for mixed martial arts (MMA) training. For this, we analyzed 2814 rounds of all weight divisions by motor actions and spatiotemporal changes according actions and time of the Keeping distance, Clinch and Groundwork combat phases. We observed differences between weight divisions in the keeping distance on stand-up combat (p ≤ 0.001; with lower time in Featherweight 131.4 s and bantamweight 127.9 s) clinch without attack (p ≤ 0.001; with higher timer in Flyweight 11.4 s and Half-middleweight 12.6 s) and groundwork without attack (p ≤ 0.001; with higher timer in Half-middleweight 0.9 s). During keeping distance, half-middleweight presented a higher frequency of Head Strikes Landed (p = 0.026; 7 ± 8 times) and attempted (p = 0.003; 24 ± 22 times). In clinch actions heavyweight present a higher frequency (p ≤ 0.023) of head strike landed (3 ± 7 times) and attempted (4 ± 9 times) and half-middleweight for body strikes (p ≤ 0.023) landed (2 ± 5 times) and attempted (3 ± 5 times). At the last, during groundwork, Bantamweight present a higher frequency (p ≤ 0.036) of head strikes landed (8 ± 10 times) and attempted (10 ± 13 times) body strikes landed (p ≤ 0.044; 3 ± 5 times) and attempted (3 ± 6 times). This study reveals important point to training and provide a challenge applied referential to the conditioning plains. From the weight divisions differences should be aware of the increase in the frequency of distance actions, especially in light and middleweights. On the Ground, bantamweight can focus on striking and grappling actions than others.     

自动情绪调节对负性情绪面孔注意偏向的影响

本研究通过成语匹配任务启动情绪调节目标,在情绪flanker任务中考察了自动情绪调节启动对注意偏向的影响。结果表明,中性启动条件下,被试表现出对负性情绪面孔的注意偏向,而情绪调节启动条件下,被试对正性、负性情绪面孔的注意分配不存在显著差异。这一结果说明自动情绪调节可以有效地减弱被试的负性情绪面孔注意偏向。     

用双任务测定技术测量手-脚协调水平

基于多重任务的心理信息加工原理,提出一种可以更好地利用分离的双重任务操作绩效测量和计算操作者手脚协调能力的方法,并提出手-脚协调估计值K的计算方法。经手脚协调任务实验验证,手-脚协调估计值K可以较好地用于测量操作者的手脚协调能力。     

The influence of relational complexity and strategy selection on children's reasoning in the Latin Square Task

The present study focused on children's deductive reasoning when performing the Latin Square Task, an experimental task designed to explore the influence of relational complexity. Building on Birney, Halford, and Andrew's (2006) research, we created a version of the task that minimized nonrelational factors and introduced new categories of items. The results of two experiments conducted with school-aged children yielded an apparent dilution of complexity effects and suggest that specific inferential strategies can reduce the relational complexity that children need to process. A theoretical account is proposed emphasizing the influence of adaptive selection of strategies that mediate processing capacity constraints in reasoning development.     

Sequencing and Optimization Within an Embodied Task Dynamic Model

A model of gestural sequencing in speech is proposed that aspires to producing biologically plausible fluent and efficient movement in generating an utterance. We have previously proposed a modification of the well‐known task dynamic implementation of articulatory phonology such that any given articulatory movement can be associated with a quantification of effort ( Simko & Cummins, 2010 ). To this we add a quantitative cost that decreases as speech gestures become more precise, and hence intelligible, and a third cost component that places a premium on the duration of an utterance. Together, these three cost elements allow us to derive algorithmically optimal sequences of gestures and dynamical parameters for generating articulator movement. We show that the optimized movement displays many timing characteristics that are representative of real speech movement, capturing subtle details of relative timing between gestures. Optimal movement sequences also display invariances in timing that suggest syllable‐level coordination for CV sequences. We explore the behavior of the model as prosodic context is manipulated in two dimensions: clarity of articulation and speech rate. Smooth, fluid, and efficient movements result.