Alterations in stride-to-stride variability during walking in individuals with chronic ankle instability

The aim of this study was to evaluate stride-to-stride variability of the lower extremity during walking in individuals with and without chronic ankle instability (CAI) using a nonlinear analysis. Twenty-five participants with self-reported CAI and 27 healthy control participants volunteered for this study. Participants walked on a motor-driven treadmill for 3 min at their selected speed. Lower extremity kinematics in the sagittal and frontal planes were recorded using a passive retroreflective marker motion capture system. The temporal structure of walking variability was analyzed with sample entropy (SampEn). The CAI group produced lower SampEn values in frontal-plane ankle kinematics compared to the control group (P = .04). No significant group differences were observed for SampEn values of other kinematics (P > .05). Participants with CAI demonstrated less stride-to-stride variability of the frontal plane ankle kinematics compared to healthy controls. Decreased variability of walking patterns demonstrated by participants with CAI indicates that the presence of CAI may be associated with a less adaptable sensorimotor system to environmental changes. The altered sensorimotor function associated with CAI may be targets for clinical interventions, and it is critical to explore how interventions protocols affect sensorimotor system function.     

The role of eye movements in motor sequence learning

An experiment that utilized a 16-element movement sequence was designed to determine the impact of eye movements on sequence learning. The participants were randomly assigned to two experimental groups: a group that was permitted to use eye movements (FREE) and a second group (FIX) that was instructed to fixate on a marker during acquisition (ACQ). A retention test (RET) was designed to provide a measure of learning, and two transfer tests were designed to determine the extent to which eye movements influenced sequence learning. The results demonstrated that both groups decreased the response time to produce the sequence, but the participants in the FREE group performed the sequence more quickly than participants of the FIX group during the ACQ, RET and the two transfer tests. Furthermore, continuous visual control of response execution was reduced over the course of learning. The results of the transfer tests indicated that oculomotor information regarding the sequence can be stored in memory and enhances response production.     

Imitation: definitions, evidence, and mechanisms

Imitation can be defined as the copying of behavior. To a biologist, interest in imitation is focused on its adaptive value for the survival of the organism, but to a psychologist, the mechanisms responsible for imitation are the most interesting. For psychologists, the most important cases of imitation are those that involve demonstrated behavior that the imitator cannot see when it performs the behavior (e.g., scratching one's head). Such examples of imitation are sometimes referred to as opaque imitation because they are difficult to account for without positing cognitive mechanisms, such as perspective taking, that most animals have not been acknowledged to have. The present review first identifies various forms of social influence and social learning that do not qualify as opaque imitation, including species-typical mechanisms (e.g., mimicry and contagion), motivational mechanisms (e.g., social facilitation, incentive motivation, transfer of fear), attentional mechanisms (e.g., local enhancement, stimulus enhancement), imprinting, following, observational conditioning, and learning how the environment works (affordance learning). It then presents evidence for different forms of opaque imitation in animals, and identifies characteristics of human imitation that have been proposed to distinguish it from animal imitation. Finally, it examines the role played in opaque imitation by demonstrator reinforcement and observer motivation. Although accounts of imitation have been proposed that vary in their level of analysis from neural to cognitive, at present no theory of imitation appears to be adequate to account for the varied results that have been found.     

Magnitude of cerebral asymmetry at rest: covariation with baseline cardiovascular activity

The cerebral regulation of cardiovascular functioning varies along both a lateral and a longitudinal axis. The parasympathetic and sympathetic nervous systems are lateralized to the left and right cerebral hemispheres, respectively. Further, the frontal lobes are known to be inhibitory in nature, whereas the temporal lobes are excitatory. However, no systematic investigation has been conducted to determine the nature and strength of the relationship between the left and right frontal and temporal lobes in regulating cardiovascular activity. The present investigation sought to examine these relationships by testing the hypothesis that negative correlations would be found between baseline heart rate and blood pressure and asymmetry of alpha magnitude across the frontal lobes. Further, positive correlations were hypothesized to exist across the temporal lobes. A total of 20 women were asked to relax with their eyes closed while heart rate and blood pressure as well as quantitative electroencephalography data were obtained. The results indicated that, as hypothesized, significant negative correlations existed across the frontal lobes and significant positive correlations existed across the temporal lobes. The results provide further support for a division of responsibility between the left and right frontal and temporal lobes in the regulation of heart rate and blood pressure.     

Social support, locus of control, and depressive symptoms in hemodialysis patients

This study aimed to reveal how social support and psychological well-being association might differ with locus of control orientation for chronically ill patients receiving a restrictive and unpleasant medical treatment (i.e., hemodialysis). Data were collected from 104 hemodialysis patients. After controlling for the variance accounted for by gender and duration of dialysis, for patients with internal locus of control, lack of "perceived social support" was found to be associated with depressive symptoms. On the other hand, for patients with external locus of control, the same analysis revealed that lack of "satisfaction from the received social support" was associated with depressive symptoms. Thus, for hemodialysis patients the variables associated with depressive symptoms varied with their locus of control orientations. Furthermore, the present study underlined the importance of considering different aspects of social support while studying with chronically ill patients.     

Observing behavior and atypically restricted stimulus control

Restricted stimulus control refers to discrimination learning with atypical limitations in the range of controlling stimuli or stimulus features. In the study reported here, 4 normally capable individuals and 10 individuals with intellectual disabilities (ID) performed two-sample delayed matching to sample. Sample-stimulus observing was recorded with an eye-tracking apparatus. High accuracy scores indicated stimulus control by both sample stimuli for the 4 nondisabled participants and 4 participants with ID, and eye tracking data showed reliable observing of all stimuli. Intermediate accuracy scores indicated restricted stimulus control for the remaining 6 participants. Their eye-tracking data showed that errors were related to failures to observe sample stimuli and relatively brief observing durations. Five of these participants were then given interventions designed to improve observing behavior. For 4 participants, the interventions resulted initially in elimination of observing failures, increased observing durations, and increased accuracy. For 2 of these participants, contingencies sufficient to maintain adequate observing were not always sufficient to maintain high accuracy; subsequent procedure modifications restored it, however. For the 5th participant, initial improvements in observing were not accompanied by improved accuracy, an apparent instance of observing without attending; accuracy improved only after an additional intervention that imposed contingencies on observing behavior. Thus, interventions that control observing behavior seem necessary but may not always be sufficient for the remediation of restricted stimulus control.     

Simulating Natural History: Walking with Dinosaurs as Hyper-Real Edutainment

Abstract

Real-world experiments that test new technologies can affect policy and practice by introducing new objects of intervention through tinkering; the ad hoc work of realigning relations in the face of frictions, surprises, and disturbances that occur when introducing a technology. In a pilot study on aggression detection, tinkering moved aggression in and out of the human body. In the end, the pilot defined aggression as a set of acoustic-physical variables representing the aroused human body, alongside other signals of aggression. How aggression as an object intervention was shaped by tinkering is relevant because it involved inclusions and exclusions by the authorities who identified aggression, the methods they applied, and mandate for intervention. A focus on relations that are tinkered within a real-world experiment permits critical engagement with this format. Although the real-world experimental format is credited with producing knowledge about a technology's ‘actual’ performance, actors and events at the pilot study location were made only selectively relevant. Analyses of real-world experiments should therefore explain how experiments selectively make the world relevant, giving only particular objects of intervention a truth status.     

大连某医院体检人群血脂四项的调查分析

对大连地区健康成人血清总胆固醇（TC）、血清甘油三脂（TG）、高密度脂蛋白胆固醇（HDL-C）和低密度脂蛋白胆固醇（LDL-C）进行调查研究.选取2009年4月至2010年12月大连地区16 052名健康体检者,并按性别和年龄分组.早晨空腹,采集所有调查对象3ml肝素抗凝血,用日立7060全自动生化分析仪检测血清TC、TG、HDL-C和LDL-C的结果.结果大连地区健康成人血脂水平比2007年发表的中国成人血脂异常防治指南所确定的正常参考区间偏高,因此,我们对大连地区人们的血脂水平必须引起高度重视,以预防和减少高脂血症及其相关疾病的发生.     

早期目标血糖管理下严重脓毒症患者HMGB1的变化及其临床意义

探讨早期目标血糖管理对严重脓毒症患者HMGB1变化的影响.严重脓毒症患者随机分为血糖控制A（4.4mmol/L~6.1mmol/L）、B（6.2mmol/L~8.3mmol/L）、C（8.4mmol/L~10.0mmol/L）三组.给予早期目标血糖管理,入ICU后0d、1d、3d、5d、7d采血测TNF-α、HMGB1浓度.三组TNF-α、HMGB1浓度及APACHEⅡ评分均呈下降趋势,A组HMGB1浓度及APACHEⅡ评分在第7d较B、C组明显降低（P＜0.05）.A组28d病死率较B、C组降低（P＆gt;0.05）.严重脓毒症患者在早期目标血糖管理下,显著降低HMGB1浓度,降低病死率和改善预后,HMGB1可用来评价脓毒症的严重程度及预后.