Level walking in adults with and without Developmental Coordination Disorder: An analysis of movement variability

Several studies have shown that Developmental Coordination Disorder (DCD) is a condition that continues beyond childhood. Although adults with DCD report difficulties with dynamic balance, as well as frequent tripping and bumping into objects, there have been no specific studies on walking in this population. Some previous work has focused on walking in children with DCD but variation in the tasks and measures used has led to inconsistent findings. The aim of the current study therefore was to examine the characteristics of level walking in adults with and without DCD. Fifteen adults with DCD and 15 typically developing (TD) controls walked barefoot at a natural pace up and down an 11 m walkway for one minute. Foot placement measures and velocity and acceleration of the body were recorded, as well as measures of movement variability. The adults with DCD showed similar gait patterns to the TD group in terms of step length, step width, double support time and stride time. The DCD group also showed similar velocity and acceleration to the TD group in the medio-lateral, anterior–posterior and vertical direction. However, the DCD group exhibited greater variability in all foot placement and some body movement measures. The finding that adults with DCD have a reduced ability to produce consistent movement patterns is discussed in relation to postural control limitations and compared to variability of walking measures found in elderly populations.     

临床专科医生培养模式探讨

毕业后医学教育是医学教育过程中一个非常重要且必不可少的组成部分。我国的医学教育体制中没有完备的毕业后医学教育层次。随着医学模式的转变以及人民大众医疗卫生保健服务需求的急剧变化,这一缺陷的弊端日益凸显。目前在我国医学教育中增加毕业后医学教育的条件已经基本具备。可采取多种途径实施该层次教育。     

影响驾驶安全的驾驶员危险知觉研究述评

危险知觉是指驾驶员对交通情境中的潜在危险进行识别并做出反应的一种能力。目前,驾驶员危险知觉测量主要使用反应时、眼动或主观评定三种测量方法。在测量中,这三种方法各有优缺点,并出现相互结合的研究趋势。为了提高我国交通安全性,结合国外在提高驾驶员危险预期能力和改善视觉搜索模式两个方面的应用研究,未来国内研究可以在探索危险知觉的认知加工特点、影响因素及加快测量技术的商品化应用等方面加以深入。     

The role of pattern recognition in children's exact enumeration of small numbers

Enumeration can be accomplished by subitizing, counting, estimation, and combinations of these processes. We investigated whether the dissociation between subitizing and counting can be observed in 4‐ to 6‐year‐olds and studied whether the maximum number of elements that can be subitized changes with age. To detect a dissociation between subitizing and counting, it is tested whether task manipulations have different effects in the subitizing than in the counting range. Task manipulations concerned duration of presentation of elements (limited, unlimited) and configuration of elements (random, line, dice). In Study 1, forty‐nine 4‐ and 5‐year‐olds were tested with a computerized enumeration task. Study 2 concerned data from 4‐, 5‐, and 6‐year‐olds, collected with Math Garden, a computer‐adaptive application to practice math. Both task manipulations affected performance in the counting, but not the subitizing range, supporting the conclusion that children use two distinct enumeration processes in the two ranges. In all age groups, the maximum number of elements that could be subitized was three. The strong effect of configuration of elements suggests that subitizing might be based on a general ability of pattern recognition.     

Toy-oriented changes during early arm movements IV: shoulder-elbow coordination

Our recent work on the initial emergence of reaching identified a mosaic of developmental changes and consistencies within the hand and joint kinematics of arm movements across the pre-reaching period. The purpose of this study was to test hypotheses regarding the coordination of hand and joint kinematics over this same pre-reaching period. Principal component analysis (PCA) was conducted on hand, shoulder, and elbow kinematic data from 15 full-term infants observed biweekly from 8 weeks of age through the week of reach onset. Separate PCAs were calculated for spatial variables and for velocity variables in trials with a toy and without a toy. From the PCA results, we constructed ‘variance profiles’ to reflect the coordinative structure of the hand, shoulder, and elbow. By coordinative structure is meant here the relative contribution of each joint to the factors revealed by the PCA. Shifts in these profiles, which reflected coordination changes, were compared across the hand and joints within each pre-reaching phase (Early, Mid, Late) as well as across phases and trial conditions (no-toy and toy). Results identified both surprising consistencies and important developmental changes in coordination. First, over development, spatial coordination changed in different ways for the shoulder and elbow. Between the Early and Late phases, spatial coordination at the shoulder showed more adult-like coordination during both spontaneous movements and movements with a toy present. In contrast, elbow spatial coordination became more adult-like only during movements with a toy and less adult-like during spontaneous movements. Second, over development, velocity coordination became more adult-like at both joints in movements with and without a toy present. We propose that the features of coordination that changed over development suggest explanations for the differential roles and developmental trajectories of the control of arm movements between the shoulder and elbow. We propose that features that remained consistent over development suggest the presence of developmentally important constraints inherent in arm biomechanics, which may simplify arm control for reaching. Taken together, these findings highlight the critical role of spontaneous arm movements in the emergence of purposeful reaching.     

Upper limb movement analysis during gait in multiple sclerosis patients

PurposeGait disorders in multiple sclerosis (MS) are well studied; however, no previous study has described upper limb movements during gait. However, upper limb movements have an important role during locomotion and can be altered in MS patients due to direct MS lesions or mechanisms of compensation. The aim of this study was to describe the arm movements during gait in a population of MS patients with low disability compared with a healthy control group.MethodsIn this observational study we analyzed the arm movements during gait in 52 outpatients (mean age: 39.7 ± 9.6 years, female: 40%) with relapsing-remitting MS with low disability (mean EDSS: 2 ± 1) and 25 healthy age-matched controls using a 3-dimension gait analysis.ResultsMS patients walked slower, with increased mean elbow flexion and decreased amplitude of elbow flexion (ROM) compared to the control group, whereas shoulder and hand movements were similar to controls. These differences were not explained by age or disability.ConclusionUpper limb alterations in movement during gait in MS patients with low disability can be characterized by an increase in mean elbow flexion and a decrease in amplitude (ROM) for elbow flexion/extension. This upper limb movement pattern should be considered as a new component of gait disorders in MS and may reflect subtle motor deficits or the use of compensatory mechanisms.     

Multivariate pattern analysis of event-related potentials predicts the subjective relevance of everyday objects

Potentially decision-relevant stimuli have been proposed to undergo immediate semantic processing. The current study investigated whether information regarding the general desirability (‘Wanting’) of visually presented ‘everyday’ objects was rapidly and automatically processed. Participants completed a foreground task while their electroencephalogram (EEG) was recorded, and task-irrelevant images were presented in the background. Following this, participants rated the images with regards to Wanting and the potentially related attributes of Relevance, Familiarity, Aesthetic Pleasantness and Time Reference. Multivariate pattern classification was used to predict the ratings from patterns of EEG data. Prediction of Wanting and Relevance was possible between 100 and 150 ms following stimulus presentation. The other dimensions could not be predicted. Wanting and Relevance ratings were highly correlated and displayed similar feature weight maps. The current results suggest that the general desirability and subjective relevance of everyday objects is rapidly and automatically processed for a wide range of visual stimuli.     

The role of visible persistence for perception of visual bilateral symmetry1

Abstract: Although the detection of visual bilateral symmetry has been claimed to be highly efficient, the possible involvement and function of visual memory in such efficient mechanisms has rarely been examined. We hypothesized that symmetry perception is rapid, as it can be achieved from rapidly decaying information of visible persistence. To test this hypothesis, we employed a temporal integration paradigm. A symmetric dot pattern was randomly divided into two asymmetric patterns and presented successively with a blank screen presented between patterns. Observers could detect symmetry when the two patterns were presented close in time (Experiment 1), indicating that observers perceived symmetry presumably utilizing visible persistence. In addition, the inverse‐intensity effect of visible persistence (Di Lollo & Bischof, 1995) was evident in our temporal integration task of symmetry (Experiment 2). The results of the current study clearly demonstrate that the detection of symmetry can be achieved based on the visible persistence. The large capacity and high spatial precision of visible persistence might be adequate for the rapid and spatially global encoding of visual symmetry.     

浅析专家会诊中心在门诊医疗中的作用

随着物质生活水平的日益提高,人们对医疗、保健的需求越来越高。为缓解看专家门诊难和在门诊能及时解决疑难杂症会诊问题,江苏省人民医院于1997年成立了高级专家会诊中心。中心成立十余年来,会诊、就诊的患者逐年增多,中心以优质的服务,得到患者的好评,作为门诊医疗的“特殊”窗口发挥了越来越大的作用。