A simulation study of the degrees of freedom of movement in reaching and grasping

The question of independently controlled components in the act of reaching and grasping has attracted interest experimentally and theoretically. Data from 35 studies were recently found consistent with simulated kinematic finger and thumb trajectories optimised for minimum jerk. The present study closely reproduces those trajectories using a discrete-time model based on minimum acceleration. That model was further used to generate two-dimensional trajectories for finger and thumb to reach and grasp an elliptical object with varying position and/or orientation. Orthogonalisation of these four trajectories revealed one degree of freedom when direction of reach was constant and two degrees of freedom when direction of reach varied, irrespective of object distance and orientation. These simulations indicate that reach and grasp movements contain redundancy that is removable by formation of task-dependent synergies. As skilled movement can be planned and executed in a low dimension workspace, control of these independent components lessens central workload.     

时间、目的与行为特征对群体决策绩效的影响

96名大学生,4人一组,参加了评价警察行为的决策实验.研究采用2×2×2(时间×目的×行为特征)因子式设计,旨在分析时间、目的和行为特征如何对中国人群体决策行为产生影响.结果表明,决策群体在行为记忆上的准确性优于成员个体,但群体的决策标准比个体冒险;时间、目的及行为特征影响群体决策的绩效.结论支持了"互补性假设"及K R Murplhy对时间与目的之间交互作用的解释.     

张三丰的文艺理论思想初探

本文在占有翔实资料的基础上,对张三丰的道教文艺理论思想进行了重新审视,并从两个方面进行了详细的分析:一、"道"、"时"相联的思想;二、"灵性"观的提出.放到中国古代文艺理论中,可以发现,张三丰的文艺理论思想是整个古代文论的一个有机组成部分,不可或缺.因此,本文对张三丰文艺理论思想的研究和探讨具有一定的代表性.     

Classification of Antisocial Behaviors Along Severity and Frequency Parameters

Antisocial behaviors were systematically classified along a hierarchy of seriousness or severity that also accounted for frequency of occurrence and heterogeneity of behaviors. Items from the CD and ODD schedules of the NIMH DISC-IV and from the Elliot Delinquency Scales were listed at specified frequencies. Nine mental health clinicians rated the level of seriousness of each alternative on a scale from 0 (trivial) to 5 (very serious). Reliability of the ratings was assessed. Over two thirds of the items showed excellent agreement among the raters, 8% showed poor agreement and 21% showed fair to moderate agreement. The overall reliability of a single rater’s score was 0.56 and the reliability of the average was 0.84. The classification meets high psychometric standards for reliability and has face validity. The final output provides a classification along a spectrum that takes into account severity, frequency of occurrence during the previous year, and presence of multiple behaviors. It is useful for classification purposes and for longitudinal tracking of antisocial behavior.     

The planning and execution of sequential eye movements: saccades do not show the one target advantage

The present experiment examined the one-target advantage (OTA) with regard to saccadic eye movements. The OTA, previously found with manual pointing responses, refers to the finding that movements are executed faster when the limb is allowed to stop on the target compared to the situation where it has to proceed and hit a second target. Using an adapted limb movement OTA task, saccades of 5 degrees and 15 degrees were made to (a) a single target (one-target), (b) one target and immediately to another target without a change in direction (two-target-extension), and (c) one target and immediately back to the start location (two-target-reversal). Unlike manual movements, the movement times for the initial saccade in the two-target-extension condition were not prolonged compared to either of the other two conditions. Moreover, this pattern of results was found for both the shorter and longer amplitude saccades. The results indicate that the OTA does not occur in the oculomotor system and therefore is not a general motor control phenomenon.     

三维倾斜平面的返回抑制

以随机点立体图为实验材料,采用三维空间线索－目标范式,将刺激呈现于同一视野位置以排除眼跳因素干扰,通过观察有意注意倾斜平面和无意注意倾斜平面与测试平面间的方向一致性和角度一致性对检测平面加工的影响,探讨了注意在不同倾斜平面间的转移是否产生返回抑制。结果表明：（1）以视差线索构造的三维视觉空间中,存在与注意有关的返回抑制效应;（2）无意注意加工能导致返回抑制,注意引导平面比无意注意平面引起更大的抑制效应。本研究的结果支持Posner返回抑制是由注意转移所致的观点     

Nest box entrance hole size can influence nest site selection and nest defence behaviour in Japanese tits

Animal Cognition - Birds have the ability to assess the risk of predation in their environment and adjust their antipredation strategies based on this risk information. However, whether nest site...     

提取抑制:来自听觉定向遗忘的证据

两个实验采用语音材料考察了词表表达方式下听觉通道的定向遗忘效应以及相应的机制。实验一中,采用2（组别）×2（词表）混合实验设计获得了听觉通道的定向遗忘效应,但是较为模糊,部分数据显示可能是额外的被试个体差异导致的;实验二中,采用2（性别）×2（词表）×2（条件）×2（科系）混合实验设计,严格控制了被试个体差异等因素,获得了较清晰的定向遗忘效应,且支持提取抑制理论。     

从哲学视角看量子干涉、纠缠与消相干

量子干涉、纠缠以及消相干是量子信息理论的三大重要概念,同时也是哲学所要关注的重要物理学前沿概念.不管是从历史的发展脉络、还是从概念之精细分析,这三大概念皆保持了一种关联性.基于这三大概念的意义和关联性分析,本文概括了由它们所触发的典型哲学问题,笔者认为,这些典型问题包括:宏观量子态的制备、非相互作用与相互作用、还原与突现、理论的客观性与主观性、实在论与反实在论.     

高效率学习的心理机制研究

本课题通过一系列研究,发现要实现高效率学习,应在知识呈现符合学生认识规律的情况下,具备以下五个主要心理要素:选择性注意是实现高效率学习的前提,元认知是高效率学习的监控系统,非智力因素是高效率学习的动力源泉,学习策略是实现高效率学习的保障,内隐认知,特别是内隐学习是高效率学习的特殊形式。