垂直-水平错觉对手控追踪绩效的影响（英文）

目的探讨垂直-水平错觉对手控追踪绩效的影响。方法研究分实验1和实验2进行。实验1a为单因素(垂直-水平线段类型:垂直水平、垂直=水平、垂直水平)被试内设计,要求25名志愿者判断哪条线段更长。实验1b中,25名志愿者根据在行为测查中得到的错觉程度,分别归入高错觉组或低错觉组,同步采集ERP数据。实验2由36名志愿者首先完成线段长度判断任务(实验材料与流程同实验1a);垂直-水平线段错觉程度的计算方法同实验1b。其次要求完成30次追踪任务。结果垂直-水平错觉程度的大小会影响手控追踪作业的绩效,错觉程度小的个体其追踪绩效会更好。结论垂直-水平错觉有可能成为预测个体手控追踪能力的辅助指标之一,可为特殊人员选拔和训练提供新思路。     

飞行任务中分心物的速度与数量变化对手眼协调追踪绩效的影响

目的通过比较不同任务条件下的持续追踪时间,考察在多目标追踪范式下个体的手眼协调追踪绩效。方法采用多目标追踪的变式,志愿者用鼠标操控红色方块—飞机,躲避运动的若干蓝色方块—干扰物,飞机碰触到干扰物或灰色边界,任务结束,记录志愿者的持续追踪时间。结果志愿者的手眼协调追踪绩效受到干扰物速度和数量的影响。当运动速度加快或干扰物数量增加,持续追踪时间下降。结论手眼协调绩效受到干扰物速度和数量的影响,速度和干扰物数量的增加使追踪成绩直线下降。     

空间站舱内多身体朝向的定向任务绩效差异仿真试验研究

目的探究三维空间中定向任务的特点,探讨在不同身体朝向条件下完成空间站模拟失重视觉环境中定向任务绩效间的差异。方法选取16名男性志愿者参加舱内定向测试任务,对不同身体朝向下的舱内定向任务绩效指标进行差异性检验;同时测量志愿者的空间能力,对空间能力绩效指标与舱内定向任务绩效指标进行相关性分析。结果不同身体朝向下的定向任务完成绩效间具有显著性差异,身体朝向相对于典型朝向偏差越大时完成定向任务的反应时越长;个体空间能力与舱内定向任务绩效之间具有显著的相关性。结论三维空间定向任务中存在"朝向依赖"效应,飞行前进行多朝向的定向训练对航天员在轨高效完成定向任务是必要的;个体空间能力可能在多朝向的舱内定向任务中发挥着重要作用。     

长期头低位卧床实验全周期个体情绪变化过程研究

目的 在90 d头低位卧床(HDBR)条件下对个体情绪变化进行全周期追踪评估.方法 以完成90 d-6°HDBR实验的36名男性志愿者为对象,志愿者按照锻炼方案分为5组,测评全周期为135天,分预适应期(卧床前15天)、严格卧床期(HDBR 90天)、恢复期(卧床后30天)三阶段,评估进程中志愿者的焦虑、抑郁、心境状态...     

基于高空VR场景的应激反应诱发范式有效性验证

目的创建一个实验室环境内可重复易操作的应激诱发范式,激发个体接近自然条件下的应激状态。方法通过虚拟现实技术和仿真道具构建出高空场景,设计了"体验高空"、"高空救猫"及"躲避飞鸟"3个任务来诱发志愿者产生应激反应,记录了44名男性大学生志愿者在5个时间点(任务前2次、任务完成即刻1次、任务后休息2次)主观报告的紧张压力程度和唾液皮质醇水平。结果志愿者在高空场景的3个任务诱发下,主观报告的应激水平在5个时间点上有显著的差异(P0.001),且在时间点3(任务完成后)达到峰值;皮质醇水平在5个时间点上有显著的差异(P0.001),且在时间点4(任务完成后15min)达到峰值。结论一方面,主观报告中个体的消极情绪在应激后显著增加,压力水平在正式任务开始前的准备阶段和练习阶段逐步升高并在任务完成后达到峰值。另一方面,应激后的唾液皮质醇水平显著提高,达到了与基于VR场景的TSST范式相似的水平。因此,初步验证了该范式在诱发应激反应上的有效性。     

认知训练对“蛟龙号”模拟驾驶作业脑力负荷影响评估

目的 创建一个实验室环境内可重复易操作的应激诱发范式, 激发个体接近自然条件下的应激状态。方法 通过虚拟现实技术和仿真道具构建出高空场景,设计了“体验高空”、“高空救猫”及“躲避飞鸟”3个任务来诱发志愿者产生应激反应,记录了44名男性大学生志愿者在5个时间点(任务前2次、任务完成即刻1次、任务后休息2次)主观报告的紧张压力程度和唾液皮质醇水平。结果 志愿者在高空场景的3个任务诱发下,主观报告的应激水平在5个时间点上有显著的差异(P <0.001),且在时间点3 (任务完成后)达到峰值;皮质醇水平在5个时间点上有显著的差异(P <0.001),且在时间点4(任务完成后15 min)达到峰值。结论 一方面,主观报告中个体的消极情绪在应激后显著增加,压力水平在正式任务开始前的准备阶段和练习阶段逐步升高并在任务完成后达到峰值。另一方面,应激后的唾液皮质醇水平显著提高,达到了与基于VR场景的TSST范式相似的水平。因此,初步验证了该范式在诱发应激反应上的有效性。     

Stroop效应在冥想训练研究中的应用

目的:通过Stroop实验探讨冥想训练的神经心理学效应.方法:采用经典Stroop字色判断任务,通过e-prime2软件对4名志愿者和4名气功师进行间隔半小时的两次实验,记录被试字色判断任务的准确性和反应时间.fMRI实验采用组块设计,数据分析采用SPM8软件,对志愿者和气功师在脑内激活情况进行比较.结果:志愿者字色判断干扰任务的平均准确率略低于气功师,平均反应时较气功师为长.气功师和志愿者间fMRI实验的脑内激活存在差异,差异区域主要在左侧前额叶背外侧皮质(DLPFC)、前扣带皮质(ACC)和顶下小叶(IPL).结论:Stroop实验可以作为一种客观的手段来评价气功练习者的冲突控制能力,长期的气功练习可以提高练习者冲突控制的能力.     

基于“认知预期”的情境意识预测模型

目的通过建模对操作者情境意识水平做出量化预测,拓宽情境意识的理论和实践研究。方法研究整合了信息重要程度、训练水平、人机界面适人性设计和人员动机等几项因素,提出了"认知预期"的概念,建立了基于"认知预期"的一般性情境意识模型。并针对信息重要程度和训练水平两个因素,在手控交会对接操作实验平台上,进行了初学者和熟练者的实验验证,对比分析了预测值、操作绩效、情境意识测量值。结果实测指标和预测值的总体变化趋势一致;初学者模型预测值和绩效表现得分、SART(situational awareness rating technique)、SAGAT(situation awareness global assessment technique)分值有显著的相关关系(r0.50,P0.01);熟练者人群的总体情境意识水平可由初学者数据拟合的线性回归方程预测。结论提出的理论模型具有在手控交回对接操作任务中预测特定人群平均情境意识水平的能力。     

双重任务操作诱发疲劳期间有关生理指标变化特征研究（摘要）

目的以双重任务操作诱发脑认知疲劳为实验模型,比较相关生理心理指标动态变化特征,以探讨飞行员脑认知疲劳评价方法的敏感和有效性。方法观察50名男性志愿受试者（年龄25～47岁,平均38.4±8.5岁）在完成1～5h的＂双重任务测试＂期间的绩效指标,     

数字计算相关脑功能区偏侧化现象fMRI研究

目的 采用磁共振功能成像（fMRI）技术观察计算相关脑功能区的偏侧化现象,判断功能区偏侧化现象与利手因素及数字任务类型之间的关系,并对其原因进行初步分析。资料与方法 对7名左利手和25名右利手志愿者进行简单计算、复杂计算和数字位置判断实验。应用组块设计模式,采用GE 1．5T磁共振扫描仪,对所有志愿者行T1WI和fMRI。采用SPM99软件进行数据分析和脑功能区定位,记录各脑区激活像素数,计算偏侧化指数（LI）,利用LI评价脑功能区的偏侧化现象。结果两组志愿者在执行三种任务时额叶功能区均以利手对侧激活占优势;顶下小叶偏侧化程度较低,但均以左侧激活略明显。在执行简单计算和复杂计算时,右利手组前额皮层、运动前区LI大于左利手组,额下回后部LI小于左利手组,顶下小叶偏侧化程度两组接近。两组中,与简单计算任务相比,执行复杂计算任务时前额皮层、运动前区和顶下小叶的LI均下降,而额下回后部LI增加。结论 fMRI可以检测数字计算相关的脑功能区的偏侧化现象,偏侧化现象与利手因素和任务类型有关。     

The effect of standing desks on manual control in children and young adults

The aim of the present study was to establish if and how the additional postural constraint of standing affects accuracy and precision of goal directed naturalistic actions. Forty participants, comprising 20 young adults aged 20–23 years and 20 children aged 9–10 years completed 3 manual dexterity tasks on a tablet laptop with a handheld stylus during two separate conditions (1) while standing and (2) while seated. The order of conditions was counterbalanced across both groups of participants. The tasks were (1) a tracking task, where the stylus tracked a dot in a figure of 8 at 3 speeds, (2) an aiming task where the stylus moved from dot to dot with individual movements creating the outline of a pentagram and (3) a tracing task, where participants had to move the stylus along a static pathway or maze. Root mean squared error (RMSE), movement time and path accuracy, respectively, were used to quantify the effect that postural condition had on manual control. Overall adults were quicker and more accurate than children when performing all 3 tasks, and where the task speed was manipulated accuracy was better at slower speeds for all participants. Surprisingly, children performed these tasks more quickly and more accurately when standing compared to when sitting. In conclusion, standing at a desk while performing goal directed tasks did not detrimentally affect children's manual control, and moreover offered a benefit.     

A comparison of the nauseogenic potential of low-frequency vertical versus horizontal linear oscillation.

The aim of this study was to compare the nauseogenic potential of low-frequency linear motion in the Earth-vertical versus the Earth-horizontal plane, delivered through the same Z-axis of the head and body. Twelve subjects were challenged with linear motion (0.3 Hz, 1.8 ms-2 rms) through the same head and body Z-axis in the Earth-vertical (sitting upright) versus horizontal (lying on the back), while either performing a continuous visual search task or with their eyes closed. Each subject completed the four conditions on a Latin square design with sessions spaced 1 week apart at the same time of day. Vertical motion was clearly more provocative than horizontal motion, and nauseogenicity of motion was exacerbated by a visual search task. Motion sickness impaired performance of the search task. Motion Sickness Susceptibility Questionnaire (MSSQ) scores correlated with individual susceptibility to the motion challenge. Mean sickness ratings for vertical motion showed some correspondence with those predicted by mathematical models of motion sickness dose response relationships.     

Mitochondrial macrohaplogroup associated with muscle power in healthy adults

The present study was undertaken to examine the effect of mitochondrial haplogroups on aerobic and anaerobic performance phenotypes such as maximum oxygen consumption, muscle power, and muscle mass. We recruited 474 healthy Japanese individuals and measured their physical performance phenotypes such as peak oxygen uptake, muscle power, and muscle mass. The genotypes for 186 polymorphisms in the mitochondrial DNA were determined, and the haplotypes were classified into 2 macrohaplogroups (i. e., N and M) and 12 haplogroups (i. e., F, B, A, N9a, N9b, M7a, M7b, G1, G2, D4a, D4b, and D5). When we compared the 2 major Japanese macrohaplogroups, leg extension power (P=0.0395), leg extension power based on body weight (P=0.0343), and vertical jump performance (P=0.0485) were significantly higher in subjects with mitochondrial macrohaplogroup N than in those with macrohaplogroup M. However, peak oxygen uptake was similar between the 2 groups. When we analyzed the 12 haplogroups, all of the measured parameters were similar among them. In conclusion, mitochondrial macrohaplogroup N may be one of the determinant factors of anaerobic physical performance phenotype such as muscle power.     

Quantitative assessment of small bowel motility by nonrigid registration of dynamic MR images

Evaluation of small bowel motility from two-dimensional dynamic MRI is of increasing interest for the assessment of segmental diseases such as Crohn's disease. We propose to use nonrigid image registration for automated motility analysis. Registration is particularly difficult when localized intensity changes occur (e.g., due to intraluminal flow or through-plane motion). Therefore, displacements were extracted using a joint registration and modeling of intensity changes. Results were analyzed in 10 patients with known or suspected Crohn's disease. Bowel wall displacements were assessed by tracking bowel cross-sectional markers over time. Automated tracking with the proposed technique was in good agreement with manual tracking (similar bias, improved standard deviations). The ability to quantify different grades of bowel motility was investigated by comparing direct motion measures (i.e., changes in bowel cross-sectional diameter or area) and various parametric maps, e.g., based on the Jacobian of the measured displacements with expert grading. Among these measures, the standard deviation over time of the Jacobian was the best at predicting grades from 1 (moving normally) to 4 (not moving at all) in 50 bowel regions with normal and pathologically reduced motility, yielding 93% correct classification with a 1-class tolerance (i.e., same score as the expert ± 1).     

Effect of muscle strength and movement speed on the biomechanics of rising from a chair in healthy elderly and young women

The ability to rise from a chair is an important task of daily living that is difficult for many elderly individuals to perform, and is particularly challenging when performed quickly. It is important to understand what factors limit performance of the task in older people, so that effective remedial approaches can be developed. In this study, we quantified lower-extremity muscle strength and chair-rise biomechanics in 12 young and 26 healthy elderly women during chair rise at normal and fast speeds without use of the hands. We found that hip and knee extensor torques, vertical and horizontal momentum, and vertical and horizontal ground reaction forces increased in the same way with speed for all subjects. All subjects increased their speed from normal to fast trials, but the young subjects were able to rise more quickly in the fast trials. In the normal speed trials, elderly subjects generated more trunk flexion and horizontal momentum while still in contact with the chair. Muscle activity patterns were similar for all subjects except that the elderly activated the ankle extensors earlier than the young. Although the elderly subjects were much weaker relative to body weight than the young subjects (48.5±14.1%), they were able to generate sufficient torques to perform the task. However, age-related differences suggest that chair-rise biomechanics were affected by the reduction in muscle strength, and that strength training regimens, particularly for the hip musculature, may be important to maintain chair-rise ability in the elderly.     

Effects of a novel inclined-adaptive footwear on change-of-direction performance in male athletes

BackgroundAlthough enhancing change of direction (COD) performance is a crucial factor for improving athletic performance in many sports, few studies have explored its effective methods.Research questionThis study aimed to investigate the effects of inclined-adaptive footwear (IAF) on force-time characteristics during a COD task.MethodsThirteen male team sport athletes were randomly assigned to wear IAF or footwear without adaptive technology to perform a COD60° task at their best effort. A three-dimensional force plate was used to obtain the force-time curve and related parameters at the turning step (plant foot).ResultsIAF led to a significantly higher resultant ground reaction force (GRF), horizontal GRF, vertical GRF, and horizontal/vertical ratio during the braking phase, followed by a significantly shorter contact time and higher resultant horizontal GRF and vertical GRF during the propulsive phase.SignificanceThis indicated that a greater GRF output, redistributed GRF, and shorter contact time occurred with the IAF. Therefore, IAF has the potential to enhance COD performance for sports involving multi-directional footwork and contribute to the development of new functional footwear.     

次任务技术对追踪负荷的测评敏感性

目的旨在研究次任务技术用于视觉追踪作业工作负荷测评的敏感性。方法采用模拟作业情境和主、次任务技术。主任务为追踪作业，分４种状况，以平均追踪误差距离为绩效指标，次任务是以几何图形为刺激目标的记忆搜寻作业，以目标反应时变化率和总反应时变化率为绩效指标，采用重复测量的受试者内设计。结果发现次任务绩效指标对追踪负荷具有较高的测评敏感性，但与主任务测定结果存在差异。结论次任务技术的敏感性受操作者资源分配策略倾向的显著影响。     

Evaluation of methods for normalizing muscle strength in elite and young athletes

BACKGROUND: The following equation has been most often used in order to present recorded muscle strength (F) normalised for various measures of body size (such as body mass m) Fnor = F x m(-b). Since previous studies have provided inconsistent results, the purpose of the present one was to assess the value of the exponential parameter b (b-value) that (a) provides both the normalised strength independent of body mass and (b) demonstrates the highest possible correlation between the normalised strength and standard tests of movement performance. METHODS: Thirteen groups of male and female athletes of both different age and different sport specialisation were tested for maximal isometric force of various leg muscle groups, as well as for vertical and standing long jump. RESULTS: The data obtained on most of the experimental groups suggested that the b-value close to the theoretically predicted b=0.67, but also different from b=0 and b=1, should be used for calculation of the normalised strength independent of body mass. Although the strength normalised using b=0.67 and b=1 demonstrated higher correlation with jumping performance than the non-normalised strength (i.e., b=0), the data also suggested that b>1 could provide the highest prediction of movement performance. CONCLUSIONS: Muscle strength should be calculated as force per kg(2/3) rather than as absolute force or force calculated per kg of body mass in order to assess strength independent of body size in routine testing of muscle function. However, different and probably task specific normalisation methods could be required in order to predict performance of various movement tasks by assessed muscle strength.     

Performance evaluation of the X-sight spine tracking system for abdominal tumors distal to spine: A 2D dosimetric analysis

The X-sight spine tracking system was integrated with Cyberknife unit to deliver radiosurgery treatments for spinal tumors without fiducial placement. However the tracking system can also be used for the treatment of abdominal tumors located in a certain distance from the spine. The aim of our study is to evaluate the tracking performance of the X-sight spine system for abdominal tumors distal to spine based on the 3 factors: tumor distance from the reference vertebra, the angle of tumor with the vertebra, and the amplitude of tumor motion due to respiration. An experimental setup was designed mainly with ovine lumbar vertebrae and the BrainLab ExacTrac gating phantom. Planning Target Volume (PTV) structures were delineated at different vertical distances from the reference vertebra. The dosimetric measurements were taken with GafChromic EBT3 film placed between slab phantoms so that they corresponded to centers of the target volumes. Dosimetric comparisons were performed based on dose-volume parameters and the gamma analysis. The measurements were then repeated for the same experimental conditions by using the Synchrony system to compare tracking performances. Using the X-sight system, percentage differences between the dose-volume parameters of the Treatment Planning System (TPS) calculations and the EBT3 film readings went up to 12% for the motion amplitude of 8 mm. The differences decreased with small motions while angles and vertical distances of the lesion locations did not induce major changes in dose discrepancies. Percentages of pixels passing gamma analysis were found to be below the acceptance threshold of 95%. Using the Synchrony system, the measured dose distributions had more similar patterns with those of the TPS system such that the percentage differences in the dose parameters were less than 4% and the gamma passing rates were found to be higher than 95%. Our results showed that the X-sight spine system should not be chosen for tracking abdominal tumors distal to the spine or osseous structures because of the effect of diaphragmatic motion on entire abdominal region. The fiducial-based Synchrony tracking system can be preferred for these tumors.     

Relationships between postural balance, rifle stability and shooting accuracy among novice rifle shooters

The present study examined the relationships between shooting accuracy and shooters' behavioral performance, i.e., postural balance and gun barrel stability, among novice rifle shooters in intra- and inter-individual levels. Postural balance and rifle stability were assessed in terms of anteroposterior (VEL(AP)) and mediolateral (VEL(ML)) sway velocity of the movement of center of pressure, and horizontal (DEV(H)) and vertical (DEV(V)) deviation of the aiming point. The participants (n=58) performed 30 shots in the standing position at a distance of 10 m from the target. The data showed that shooting accuracy was related to postural balance and rifle stability, but only at the inter-individual level. The correlation coefficients between shooting score and behavioral performance variables ranged from -0.29 to -0.45. The stepwise multiple regression analysis revealed that the VEL(ML) and the DEV(H) as independent variables accounted for 26% of the variance in the shooting score. The results also suggested that postural balance is related to the shooting accuracy both directly and indirectly through rifle stability. As the role of postural balance appeared to be important in shooting performance, the use of additional balance training programs to improve a shooter's postural skills should be encouraged.