The coupling of head,reach and grasp movement in nine months old infant prehension

In 9-month-old-infants adjustments in the reaching pattern to sudden changes in object location were examined. An attractive ball was presented to the infants at their midline and on some trials (perturbation trials) the ball suddenly changed position 15 cm to the right or left during the reach. For the perturbed trials the movement times approximately doubled compared to the control trials and significantly fewer balls were grasped. The results indicate that infants need to finish the first movement before being able to redirect the reach to a new destination. The correlation between the latency of the head and hand adjustment to the perturbation were 0.85 and 0.78 for movements to the left and to the right, respectively, indicating a tight coupling. The time between the start of the perturbation and peak velocity (TPPV) was significantly shorter for the head movement than for the hand movement, indicating that the head is leading the hand.     

Coupling of postural and manual tasks in expert performers

The purpose of this study was to investigate the integration of bimanual rhythmic movements and posture in expert marching percussionists. Participants (N = 11) performed three rhythmic manual tasks [1:1, 2:3, and 2:3-F (2:3 rhythm played faster at a self-selected tempo)] in one of three postures: sitting, standing on one foot, and standing on two feet. Discrete relative phase, postural time-to-contact, and coherence analysis were used to analyze the performance of the manual task, postural control, and the integration between postural and manual performance. Across all three rhythms, discrete relative phase mean and variability results showed no effects of posture on rhythmic performance. The complexity of the manual task (1:1 vs. 2:3) had no effect on postural time-to-contact. However, increasing the tempo of the manual task (2:3 vs. 2:3-F) did result in a decreased postural time-to-contact in the two-footed posture. Coherence analysis revealed that the coupling between the postural and manual task significantly decreased as a function of postural difficulty (going from a two-footed to a one-footed posture) and rhythmic complexity (1:1 vs. 2:3). Taken together, these results demonstrate that expert marching percussionists systematically decouple postural and manual fluctuations in order to preserve the performance of the rhythmic movement task.     

Representative design: Does the addition of a defender change the execution of a basketball shot?

ObjectiveThe aim of this study was to examine the influence of a defender on the performance of a motor skill from an invasion sport.DesignHighly skilled basketball players performed different variations of basketball shots using a randomised test schedule.MethodParticipants completed a total of 30 test trials comprising 6 trials of 5 different shot types in both defended and undefended conditions.ResultsThe presence of a defender led to significant changes in several behavioral measures including faster shot execution times, longer jump times, and an increase in the amount of time that the ball spent in the air as it travelled to the basket after being released from the shooter's hand. These behavioral changes were accompanied by an overall decline in shooting accuracy of over 20%. Defended shots also tended to elicit greater amounts of movement variability which, when interpreted in conjunction with the other findings, suggests that participants were attempting to adapt their movements to accommodate for the changing demands of the performance environment. Comparisons across different shot types revealed that the influence of the defender was generally context and task dependent.ConclusionsThe results have important implications for representative task design, and highlight how the manipulation of key information sources can have a marked effect upon behavioral responses.     

情境模型中的时间表征研究

阅读理解中情境模型的建构是当今阅读研究的热点 ,自Zwaan等人提出事件标记模型理论以来 ,很多研究者对影响情境模型建构的空间维度进行了深入的研究 ,尽管对情境模型中时间维度的研究相对缺乏 ,但仍得出了一些有价值的研究成果。本文对情境模型中时间表征的理论假设、实验研究、技术手段及主要研究结论作了介绍和评析 ,并对未来的研究方向进行了展望。     

Normal Modal Substructural Logics with Strong Negation

We introduce modal propositional substructural logics with strong negation, and prove the completeness theorems (with respect to Kripke models) for these logics.     

A Predicate Logical Extension of a Subintuitionistic Propositional Logic

We develop a predicate logical extension of a subintuitionistic propositional logic. Therefore a Hilbert type calculus and a Kripke type model are given. The propositional logic is formulated to axiomatize the idea of strategic weakening of Kripke's semantic for intuitionistic logic: dropping the semantical condition of heredity or persistence leads to a nonmonotonic model. On the syntactic side this leads to a certain restriction imposed on the deduction theorem. By means of a Henkin argument strong completeness is proved making use of predicate logical principles, which are only classically acceptable.     

The amount of recent action-outcome coupling modulates the mechanisms of the intentional binding effect: A behavioral and ERP study

Our everyday interactions depend on the ability to maintain a feeling of control over our bodily actions, that is, the sense of agency. The intentional binding effect – a perceived temporal shortening between voluntary actions and sensory outcomes – has been shown to implicitly measure agency. We investigated the effect’s underlying mechanisms: prediction and retrospective inference. First, long-term and recent action-outcome coupling were compared. Second, brain activity was recorded to uncover the neural correlates of the two mechanisms. Our results show that the recent accumulation of action-outcome coupling, but not that of a long-term accumulation, is correlated with the binding effect of actions and accounts for both mechanisms. Temporal action binding was reflected in both the readiness potential and the auditory evoked potential. The results shed new light on our understanding of the influence that immediate context of an action has on its temporal binding and the neural substrate of human agency.     

流行病防控的伦理分析

目前学界对流行病防控的伦理探讨尚十分欠缺,而现有的生命医学伦理学理论不能较好地解决流行病防控中的伦理问题,应用伦理学亟需对流行病防控做出伦理回应。流行病防控中主要涉及隐私、自由和正义三个方面的伦理问题,亦即个人权利或自由与公共健康的冲突问题。流行病防控对个人行为的家长主义干预,特别是对个人自愿自涉行为的强家长主义干预必须得到伦理证明。流行病防控与社会正义和人权也有十分密切的关系,促进正义与保护人权是流行病防控的应有之意。     

时间人格的结构与功能

时间人格是个体对时间情境稳定的适应倾向及能力特征, 其主要功能是适应时间情境并影响身心健康。已有的研究从时间洞察力、时间定向、时间管理、时间紧迫感、拖延性等方面对时间人格进行了探讨, 最近的研究则转向构建综合的时间人格结构模型。本文针对时间概念、时间人格概念和研究范式的争论, 提出未来的研究应继续完善时间人格结构模型, 加强外部影响因素研究, 补充过程研究、质性研究和跨文化研究, 并在进化论、文化学和脑科学方面获取支持。     

Conflict in the kitchen: Contextual modulation of responsiveness to affordances

Recently, human behavior has been considered the product of continuous interactions between perception, cognition and action in which “affordances” (action possibilities the environment has to offer) play an important role. Converging evidence suggests that multiple action possibilities simultaneously compete for further processing, while external and internal factors (e.g., incoming sensory information, predictions) bias this competition. In the present study we used a stop-task to investigate whether context is able to modulate the strength of the responsiveness to affordances. We therefore placed participants in an actual kitchen and workshop during electroencephalographic recordings. A faster response to context congruent objects demonstrated that the direct surrounding is able to affect responsiveness to affordances. In addition, when responses needed to be withheld, context congruent objects evoked greater response conflict as indicated by an enhanced N2 Event Related Potential (ERP) component.