The Effects of Objectives and Constraints on Motor Control Strategy in Reciprocal Aiming Movements

The goal of this study was to examine how the kinematics of reciprocal aiming movements were affected by both the objective of the movement and the constraints operating on that movement. In Experiment 1, the objective of the movement was indirectly manipulated by capitalizing on the fact that subjects determine their own accuracy and speed limits, despite uniform task instructions to move as quickly and accurately as possible. A Fitts' type reciprocal aiming paradigm was employed, in which 69 subjects were asked to move a stylus repetitively between two spatially separated targets. Four target widths were orthogonally combined with four movement amplitudes, resulting in 16 conditions. Movements were made on an X-Y digitizing tablet. Based on the mean variable error produced on both targets, subjects were differentiated post hoc into three movement objective groups: speed, accuracy, and speed-plus-accuracy. Kinematic analyses revealed that the programming and execution of movements were systematically influenced by both the movement objective and the movement constraints. That is, movement time, peak velocity, dwell time, acceleration and deceleration time, normalized acceleration and normalized deceleration varied systematically as a function of both the speed-accuracy movement objective and the movement constraints of target size and movement distance. Moreover, the consequences of changing the constraints of the movement were affected by an interaction with the objective of the movement. In Experiment 2, the objective of the movement was directly manipulated by varying speed and/or accuracy instructions to subjects. The basic results of Experiment 1 were substantiated. Overall, the results were consistent with the view that motor control is dependent upon sensory consequences.     

A New Book by N. A. Bernstein: “On Dexterity and Its Development”

A book, ‘On Dexterity and its Development,’ written by N. A. Bernstein in the 1940s has recently been published in Moscow. We describe briefly the amazing fate of this miraculously saved book and of its famous author. The book is unique in its reader-friendly handling of the most complicated issues of motor control, motor development, motor skill acquisition, and more general aspects of brain activity. It presents the basis for what is now called motor control and for some of the more fundamental issues of theoretical neuroscience. Bernstein described his views on multilevel control of movements, the role of sensory feedback, preprogramming, feedback and feedforward components in motor control, the role of exercise, and other subjects. Despite the fact that the book was written nearly half a century ago, its deep philosophical content remains beyond any competition.     

Big Gods in review: introducing Ara Norenzayan and his critics

This essay introduces a review symposium on Ara Norenzayan's book Big Gods (2013). The essay reviews Norenzayan's earlier publications on religion, sums up the main points of criticism that have been put forward by the contributors, and raises some concerns about the questions to be asked about ‘religion.’     

God is great – but not necessary? On Ara Norenzayan,Big Gods (2013)

Norenzayan provides ample evidence to support the claim that beliefs about moralizing Big Gods correlate with prosocial behavior. Atheists, for their part, are the most mistrusted minority wherever there is a widespread belief in moralizing gods. Projecting these patterns of thought and behavior on to our ancestors 10 000 years back is risky, though. It is a plausible hypothesis that prosociality in societies where people meet anonymous others on a regular basis may have coevolved with beliefs about Big Gods, but it remains historically speculative and the direction of causality is impossible to establish.     

Effect of Nonspecific Chronic Low Back Pain on Walking Economy: An Observational Study

The authors investigated the effects of chronic low back pain (LBP) and walking speed (WS) on metabolic power and cost of transport (CT). Subjects with chronic nonspecific LBP (LBP group [LG]; n = 9) and healthy (control group [CG]; n = 9) were included. The test battery was divided into 3 blocks according to WS as follows: preferred self-selected speed (PS), and lower and higher than the PS. In each block, the volunteers walked 5 min, during which oxygen consumption was measured. Although without differences between groups, the LG had CT lower in slower speeds than in faster speeds. Walking speed affected CT only in the LG, which the group had the greatest walking economy at slower speeds.     

On the Hand Transport Component of Prehensile Movements

Jeannerod (1981) proposed that prehensile movements involve two independent visuomotor channels that are responsible for hand transport and hand aperture. In many studies, the movement of a marker placed on the wrist has been used as an index of hand transport because wrist movement is unaffected by the movements of the digits responsible for hand aperture. In the present study, the spatial paths of the wrist, index finger, and thumb of 5 adults, each performing 50 reaching movements, were measured with a WATSMART movement tracking system, and their variability was analyzed. The measures of movement variability suggest that the motor system is more concerned with thumb position than with wrist position during hand transport. Although the wrist is a technically convenient index of hand transport, the thumb may be a more appropriate index from the point of view of motor control.     

MUSIC THAT WILL BRING BACK THE DEAD? Resurrection,Reconciliation, and Restorative Justice in Post‐Apartheid South Africa

This essay explores how the doctrine of the Resurrection informs theological reflection on reconciliation in post-Apartheid South Africa. It begins by establishing the fragile and liminal state of reconciliation, despite the efforts of the Truth and Reconciliation Commission. It then argues that the Resurrection offers an ecstatic and relational understanding of the human, which in turn provides a basis for advancing claims regarding human dignity and well-being. In conversation with the work of Oliver O'Donovan and James Alison on the Resurrection, this view is further contextualized by incorporating insights from ubuntu and from the work of Judith Butler on grieving. The essay closes with proposals for how the church in post-Apartheid South Africa can give witness to the Resurrection in its immediate life and work through advocacy and carrying on the politics of grieving.     

FALSIFIABILITY AND TRACTION IN THEORIES OF DIVINE ACTION

One of the most focused research programs in the science‐religion dialogue that has taken place up to the present is the series of volumes published jointly by the Vatican Observatory and the Center for Theology and the Natural Sciences. Originating with the encouragement of Pope John Paul II, this series has produced seven volumes focusing on how divine action can be understood in light of contemporary science. A retrospective volume published in 2008, Scientific Perspectives on Divine Action: Twenty Years of Challenge and Progress, contains articles reviewing the series as a whole. In this article I analyze the series as a whole as well as some of the pivotal problems discussed throughout the series, such as the zero‐sum game, scientific “traction,” falsifiability in theories of divine action, and locating special divine action in the physical world.     

中国区域心理学与人文地理学的整合探索

区域心理学主张将不同区域的文化为背景来比较不同区域人群的心理共同性和差异性,它侧重不同文化背景下的区域心理与行为差异的研究,而区域心理差异的形成又受多种因素的影响,而人文地理学作为与区域心理学相呼应的学科则在很大程度上给与区域心理学很大的支持。因此,他们之间的整合既有利于区域心理学的发展,同时也可以为人文地理学的研究提供新的思路。     

“生生”、“感通”、“偕行”——《易传》的天人共生哲学

天人问题是中国哲学的基本问题,天人的基本含义之一相当于我们现在通常说的自然与人;基本含义之二是视天人为有德性(道德)的、有能动性的动态的、协调的存在。中国哲学中的这种天人观在《易传》中表现为"生生"——"感通"——"偕行"的天人共生态。《易传》既将天人视为一个"生生不息"的自然的生命有机体,又充分发掘天人的德性,并使二者相资相长,"日新之谓盛德,生生之谓易",天地人各有其位,各尽其能,各循其道,"各正性命",一体偕行,共生共存共荣。