Visual Feedback and Positioning Movements

Subjects (n = 60) performed both the reproduction and learning of a linear positioning movement under one of five visual feedback conditions. Results from two experiments indicated that visual cues from the task display augmented information available from visual feedback of the movement per se. Extraneous cues from the task display have clearly confounded the manipulation of visual feedback in previous positioning studies. When these cues are eliminated, visual distance information seems more useful than visual location information.     

Dual-Task Training Reduces Impact of Cognitive Task on Postural Sway

Given the flexible organization of locomotion evidenced in the many ways the limbs can be coordinated, the authors explored the potentially correspondingly flexible organization of nonvisual (kinesthetic) distance perception. As kinesthetic distance perception is known to be affected by how the limbs are coordinated, the authors probed the potential perceptual contribution of the arms during locomotion by manipulating arm–leg coordination patterns in blind-walked distance-matching tasks. Whereas manipulation of arm–leg coordination for walking with free-swinging arms had no observable perceptual consequences, comparable manipulation for walking with hiking poles did affect distance matching. These results suggest that under conditions in which the arms act to propel the body (e.g., crawling or stair-climbing) a person's nonvisual sense of movement is conveyed in the coordinated actions of all four limbs.     

Control of Trajectory Modifications in Target-Directed Reaching

Human reaching movements to fixed and displaced visual targets were recorded and compared with simulated movements generated by using a two-joint arm model based on the equilibrium-point (EP) hypothesis (λ model) of motor control (Feldman, 1986). The aim was to investigate the form of central control signals underlying these movements. According to this hypothesis, movements result from changes in control variables that shift the equilibrium position (EP) of the arm. At any time, muscle activations and forces will depend on the difference between the arm's EP and its actual position and on the limb's velocity. In this article, we suggest that the direction of EP shift in reaching is specified at the hand level, whereas the rate of EP shift may be specified at the hand or joint level. A common mechanism underlying reaching to fixed and displaced targets is proposed whereby the EP of the hand shifts in a straight line toward the present target. After the target is displaced, the direction of the hand EP shift is modified toward the second target. The results suggest that the rate of shift of the hand EP may be modified for movements in different parts of the work space. The model, with control signals that vary in a simple fashion over time, is able to generate the kinematic patterns observed empirically.     

A Test of the Schema Theory of Discrete Motor Learning

The recall schema in a response class of discrete movements was investigated, with variability of practice being manipulated before transfer to a new instance in the response class. After the transfer, the varied-practice group performance was superior to the continuous practice group. The interaction of the low-and high-variability groups from training to recall performance supported the prediction that a group with more variable training would exhibit an increased rate of learning when introduced to a new instance of the response class. After two days, the superiority of the high-variability group over the low disappeared, suggesting the memory representations of the two groups were no different under withdrawal of knowledge of results.     

Exploration and Selection of Intralimb Coordination Patterns in 3-Month-Old Infants

Through the exploration of their own capacities and the selection of adaptive responses, infants learn new motor solutions. Using a conjugate reinforcement mobile procedure, previous researchers have repeatedly shown that infants increase their leg kick frequency to control a mobile that is connected to their ankles. That traditional experimental design allows multiple motor solutions to the task and therefore provides limited information about the infants' capacity to explore and select specific motor solutions. The author designed a new experimental procedure to study infants' capacity to discover and adopt specific motor solutions. The new, constraining mobile reinforcement procedure requires a specific motor response and therefore the development of a more finely tuned perception—action map than has previously been experimentally demonstrated. To gain reinforcement from the mobile, infants had to produce a coordinated hip and knee extension within the same leg. The results from the 13 infant participants showed that they were capable of increasing their frequency of coordinated movements to make the mobile move. Those results suggest that infants at the age of 89–106 days are sensitive to intralimb coordination task requirements and are capable of mapping their own limb dynamics to the environmental information.     

Adaptation of Neuromuscular Synergies During Intentional Constraints of Space-Time Relationships in Human Gait

Tight frequency-to-amplitude relationships are observed in spontaneous human steady gait. They can be modified, if required; that flexibility forms a fundamental basis of the intentional adaptive capabilities of locomotion. In the present experiments, the processes underlying that flexibility were investigated at both the level of joint kinematics and the level of neuromuscular synergies. Subjects (N = 4) walked at the same speed either with a preferred or a nonpreferred frequency-to-amplitude relationship (i.e., constrained, short steps at a high frequency [COS condition] or constrained, long steps at a low frequency [COL condition]); their swing and stance phases were separately analyzed. In the COS condition, increases in EMG activity were specifically required during the swing phase. In the COL condition, several muscles required increases in EMG activity during the stance phase, but decreases of the hamstring muscles were needed during the swing phase. Whereas, in preferred walking, modification of the frequency affects the EMG patterns globally (the gain increasing with the frequency in both the stance and swing phases), the present results show that changing the frequency in a constrained manner either affects the swing phase specifically or affects both phases, but in the opposite direction. That finding indicates mat a separate control is needed in both the swing and the stance phases.     

The globalization of human rights

The argument of this article is that what I term generic globalization has created unprecedented opportunities for advances in human rights universally, but that the dominant actually existing historical form of globalization – capitalist globalization – undermines these opportunities. Substantively, I argue that taking the globalization of human rights seriously means eliminating the ideological distinction that exists between civil and political rights on the one hand, and economic and social rights on the other. Doing this systematically undermines the three central claims of capitalist globalization – namely, that globalizing corporations are the most efficient and equitable form of production, distribution and exchange; that the transnational capitalist class organizes communities and the global order in the best interests of everyone; and that the culture-ideology of consumerism will satisfy our real needs.     

Development ethics – Why? What? How? A formulation of the field

The paper assesses the rationale, contributions, structure, and challenges of the field of development ethics. Processes of social and economic transformation involve great risks and costs and great opportunities for gain, but the benefits, costs, and risks are typically hugely unevenly and inequitably distributed, as is participation in specifying what they are and their relative importance. The ethics of development examines the benefits, costs, risks, formulations, participation, and options. The paper outlines a series of ways of characterizing such work, arguments for and against its importance, and some of its major sources and contributions, especially from the interdisciplinary stream of work represented over several decades by Denis Goulet. Definitions are diverse since the work covers many different intersections of practice and theorizing, at multiple levels. The paper considers and replies to arguments against discussing development ethics: the claim that it involves only endless proliferation of different opinions, is an expensive luxury that undermines long-run development, is superfluous if one already works with the capability approach or the human rights tradition, or never has influence. Finally, it presents suggestions for how development ethics thinking can have increased impact, with reference to incorporation in policy analysis and planning methods, professional codes and training, and to its intellectual location and communication strategies. The field should articulate the methodological pragmatism which much of it has adopted, consistent with its required role as a practice-oriented interdisciplinary meeting ground.     

Ethics in Research

Summary

This article presents an overview of the history of efforts to protect human subjects in research. It discusses the establishment of international, national, organizational, and institutional procedures designed to protect human participants. The article provides a detailed summary of the principal ethical codes for research and their origins. It includes discussions of the most frequently encountered ethical issues ranging from the initial decision to undertake the project, through the selection and application of the various research procedures, to the analysis and interpretation of the data.     

Love is Better than Knowledge: Paul,Luther and a Theology of Being Human

It is said in several contemporary theologies that in acting on their proclivities, homosexuals act as a law unto themselves rather than subordinate their desires to God's law. In linking homosexuality with the notion of a selfish individualism, these theologies cast homosexuals as incapable of exercising community-building love. They sustain a reductive model of the human person that issues from an anxiety about the presence of the “secular” ideology of individualism in theology. I suggest that we rehabilitate a vision of love based on a re-reading of the Apostle Paul's understanding of love as God-given and life-giving in 1 Corinthians and Romans, and use it as the basis for a revitalized vision of being human. Guided by Martin Luther's hermeneutic and contemporary thought, this vision recognizes the interdependent relationship between self- and other-concern, and proposes that we prioritize love over reductive knowledge claims in our theologies.