When kinesthetic information is neglected in learning a Novel bimanual rhythmic coordination

Many studies have shown that rhythmic interlimb coordination involves perception of the coupled limb movements, and different sensory modalities can be used. Using visual displays to inform the coupled bimanual movement, novel bimanual coordination patterns can be learned with practice. A recent study showed that similar learning occurred without vision when a coach provided manual guidance during practice. The information provided via the two different modalities may be same (amodal) or different (modality specific). If it is different, then learning with both is a dual task, and one source of information might be used in preference to the other in performing the task when both are available. In the current study, participants learned a novel 90° bimanual coordination pattern without or with visual information in addition to kinesthesis. In posttest, all participants were tested without and with visual information in addition to kinesthesis. When tested with visual information, all participants exhibited performance that was significantly improved by practice. When tested without visual information, participants who practiced using only kinesthetic information showed improvement, but those who practiced with visual information in addition showed remarkably less improvement. The results indicate that (1) the information is not amodal, (2) use of a single type of information was preferred, and (3) the preferred information was visual. We also hypothesized that older participants might be more likely to acquire dual task performance given their greater experience of the two sensory modes in combination, but results were replicated with both 20- and 50-year-olds.     

New polytypes of long-period stacking ordered structures in a near-equilibrium Mg97Zn1Y2 alloy

By atomic-scale high-angle annular dark-field scanning transmission electron microscopy, the long-period stacking ordered (LPSO) structures in a near-equilibrium Mg₉₇Zn₁Y₂ (at.%) alloy have been characterised. In addition to 18R and 14H, new polytypes of LPSO structures are analysed and determined as 60R, 78R, 26H, 96R, 38H, 40H, 108H and 246R. All of these LPSO structures feature AB′C′A building blocks with two Mg layers and three Mg layers sandwiched between them. The Bravais lattices and space groups of new polytypes of LPSO structures were easily determined via the newly introduced method. A structural relationship between the LPSOs is proposed.     

基于fNIRS的运动执行与运动想象脑激活模式比较

使用《运动想象问卷−修订版》筛选出的30名被试(男女各半), 采用功能性近红外光谱成像技术(fNIRS)监测被试在执行实际举哑铃(男生, 4磅和8磅; 女生, 2磅和4磅)任务和想象举同等重量哑铃任务时, 其大脑皮层氧合血红蛋白浓度的变化。结果发现：男女被试在运动执行与运动想象任务下都激活了主运动皮层; 且运动执行的大脑激活水平高于运动想象。在执行实际运动任务时, 运动强度显著影响大脑皮层血氧浓度的变化, 表现出左半球偏侧化优势; 在执行想象运动任务时, 运动强度没有影响大脑皮层血氧浓度的变化, 且无偏侧化现象。     

多媒体学习中线索效应的元分析

作为多媒体学习中一种重要的指导性教学设计形式, 线索能否引导学习者的注意并促进学习效果, 目前结论尚不一致。研究运用元分析技术, 分别以保持测验、迁移测验的成绩作为学习效果的结果变量, 以线索区的注视时间、注视次数作为注意引导的结果变量, 探讨多媒体环境中的线索对学习效果和注意引导的影响, 并通过调节效应检验考察线索效应的边界条件。采用严格标准进行文献检索和筛选后, 共获取43篇符合元分析的文献。在保持测验成绩和迁移测验成绩上, 分别生成了44个(3910人)和41个(3906人)独立效应量; 在对线索区的注视时间和注视次数上, 分别生成了14个(938人)和11个(816人)独立效应量。结果发现, 线索的加入显著提高了保持测验成绩(g = 0.53)和迁移测验成绩(g = 0.36), 同时也增加了学习者对线索区的注视时间(g = 0.50)和注视次数(g = 0.70)。调节效应分析发现：在保持测验成绩上, 静态学习材料、陈述性知识、理工科条件下的线索效应分别高于动态学习材料、程序性知识和文科; 在迁移测验成绩上, 时空线索、静态学习材料、陈述性知识条件下的线索效应分别高于物理线索、动态学习材料和程序性知识; 而在眼动指标上, 线索对注意的引导主要受线索类型的调节, 物理线索条件下学习者对线索区的注视时间和注视次数均高于时空线索。结论认为, 线索的加入确实促进了学习者对学习材料的识记和理解效果, 同时也引导了学习者的注意分配; 但线索效应一定程度上受线索类型、学习材料动态性、知识类型、学科属性等因素的调节。未来研究需进一步考察线索效应的其他边界条件。     

自闭症谱系障碍的生物基础

自闭症谱系障碍是一组发病于生命早期, 由一系列生理、心理因素引起的神经发育障碍。遗传、脑神经结构、营养素等是自闭症谱系障碍的生物基础的重要来源。个体在孕育早期形成的大脑和机体异常可能是导致自闭症谱系障碍的关键。这种异常在出生后的发育中具体作用于神经活动、脑发育、免疫系统等生理途径。研究者们今后可以尝试横跨不同自闭症谱系障碍亚型、年龄和发育阶段, 开展横向与纵向相结合的大范围研究, 以进一步明确自闭症谱系障碍的生物基础。     

特征和结构信息对草图人脸识别的影响

在人脸认知研究的特征说、结构说和整体说的基础上,通过草图人脸与人脸相似程度主观评价的调查,发现五官位置、拓扑结构、五官比例、轮廓外形和五官外形等五个维度对人脸识别影响的权重依次减小,并且存在着多种显著的不同水平的交互作用。进而提出,五官位置和拓扑结构可组合成具体图形意义上的结构关系,这种结构关系将整体人脸分解成有序的特征集。     

关于临床决策问题

医生在临床工作中做出明确诊断,并据此给予有效的处理均属于决策过程。制定决策的整个过程,同时也是进行决策思维的过程。近年来高新技术的迅猛发展以及医疗费用急剧增加,使制定决策更加复杂。如何进行正确的决策思维,做出最切实可行的和最佳的决策,对避免决策的盲目性、局限性及惰性具有重要的现实意义。     

胸腺功能的发现及其对免疫学发展的影响

19世纪60年代初,免疫系统的发现使免疫学的发展方向发生了革命性转变。在这场转变的过程中,胸腺功能的发现起到了重要的作用。详述了胸腺功能的发现过程,并进一步深入到免疫学思想史,讨论了这个发现如何影响了免疫学的历史进程。