Specificity of Task Constraints and Effects of Visual Demonstrations and Verbal Instructions in Directing Learners' Search During Skill Acquisition

In the present study, the efficacy of visual demonstrations and verbal instructions as instructional constraints on the acquisition of movement coordination was investigated. Fifteen participants performed an aiming task on 100 acquisition and 20 retention trials, under 1 of 3 conditions: a modeling group (MG), a verbally directed group (VDG), and a control group (CG). The MG observed a model intermittently throughout acquisition, whereas the VDG was verbally instructed to use the model's movement pattern. Participants in the CG received neither form of instruction. Kinematic analysis revealed that compared with verbal instructions or no instructions, visual demonstrations significantly improved participants' approximation of the model's coordination pattern. No differences were found in movement outcomes. Coordination data supported the visual perception perspective on observational learning, whereas outcome data suggested that the modeling effect is mainly a function of task constraints, that is, the novelty of a movement pattern.     

Do Children Perceive Postural Constraints When Estimating Reach or Action Planning?

Estimation of whether an object is reachable from a specific body position constitutes an important aspect in effective motor planning. Researchers who estimate reachability by way of motor imagery with adults consistently report the tendency to overestimate, with some evidence of a postural effect (postural stability hypothesis). This idea suggests that perceived reaching limits depend on an individual's perceived postural constraints. Based on previous work with adults, the authors expected a significant postural effect with the Reach 2 condition, as evidenced by reduced overestimation. Furthermore, the authors hypothesized that the postural effect would be greater in younger children. They then tested these propositions among children aged 7, 9, and 11 years by asking them to estimate reach while seated (Reach 1) and in the more demanding posture of standing on 1 foot and leaning forward (Reach 2). Results indicated no age or condition difference, therefore providing no support for a postural effect. When the authors compared these data to a published report of adults, a developmental difference emerged. That is, adults recognize the perceived postural constraint of the standing position resulting in under- rather than overestimation, as displayed in the seated condition. Although preliminary, these observations suggest that estimates of reach (action planning) continue to be refined between late childhood and young adulthood.     

Interlimb Coordination: Real Constraints and False Dichotomies

Despite the recent advances in the field of coordination dynamics addressing the interplay of constraints of different natures in the emergence of human coordination, F. Mechsner (2004) invites us to revive hierarchical and dichotomous thinking by offering again his exclusive position that coordinated movements are (purely) perceptual-cognitive/psychological in nature. In this comment, the authors address a number of theoretical and methodological issues that might potentially puzzle the readers of Mechsner's article. They contend that the dichotomy proposed by Mechsner (i.e., perceptual-cognitive vs. motor) constitutes a restrictive framework for understanding human coordination.     

Interpersonal Pattern Dynamics and Adaptive Behavior in Multiagent Neurobiological Systems: Conceptual Model and Data

ABSTRACT

Ecological dynamics characterizes adaptive behavior as an emergent, self-organizing property of interpersonal interactions in complex social systems. The authors conceptualize and investigate constraints on dynamics of decisions and actions in the multiagent system of team sports. They studied coadaptive interpersonal dynamics in rugby union to model potential control parameter and collective variable relations in attacker–defender dyads. A videogrammetry analysis revealed how some agents generated fluctuations by adapting displacement velocity to create phase transitions and destabilize dyadic subsystems near the try line. Agent interpersonal dynamics exhibited characteristics of chaotic attractors and informational constraints of rugby union boxed dyadic systems into a low dimensional attractor. Data suggests that decisions and actions of agents in sports teams may be characterized as emergent, self-organizing properties, governed by laws of dynamical systems at the ecological scale. Further research needs to generalize this conceptual model of adaptive behavior in performance to other multiagent populations.     

Movement Speed and Accuracy in Space and Time: The Complementarity of Error Distributions

Movement speed-accuracy trade-off is a function of the space-time constraints of the task. We investigated the space-time account of Hancock and Newell (1985) and the hypothesis of complementarity between the four moments of the error distribution in space and time. Twelve participants performed 15 conditions in a line drawing task composed of different spatial (10, 20, and 30 cm) and temporal (250 to 2,500 ms) criteria. The results showed that all moments of distributions changed systematically between conditions but there were some departures from the Hancock and Newell predictions. In contrast, individual analysis revealed the complementarity of the spatial and temporal error including a trade-off between the four moments of error. These findings support a complementary space-time account of movement speed and accuracy.     

Perceived control effects on religiosity and quality of life among young adults

The study investigated the mediating role of perceived control in the association between religiosity and quality of life among young adults in south-west Nigeria. Data were collected from a sample of 1 050 young adults (mean age = 29.8, SD = 4.61; female = 38.7%). Regression analysis was utilised to predict quality of life from religiosity, partialling out perceived control. Findings suggest internal religiosity to predict an environmental domain of quality of life through perceived control. Perceived constraints appear to explain the association between internal religiosity and the environmental domain of quality of life.     

Uncertainty,Indeterminacy, and Agent-Centred Constraints

Common-sense morality includes various agent-centred constraints, including ones against killing unnecessarily and breaking a promise. However, it's not always clear whether, had an agent ?-ed, she would have violated a constraint. And sometimes the reason for this is not that we lack knowledge of the relevant facts, but that there is no fact about whether her ?-ing would have constituted a constraint-violation. What, then, is a constraint-accepting theory (that is, a theory that includes such constraints) to say about whether it would have been permissible for her to have ?-ed? In this paper, I canvass various possible approaches to answering this question and I argue that teleology offers the most plausible approach—teleology being the view that every act has its deontic status in virtue of how its outcome (or prospect) ranks, relative to those of its alternatives. So although, until recently, it had been thought that only deontological theories can accommodate constraints, it turns out that teleological theories not only can accommodate constraints, but can do so more plausibly than deontological theories can.     

Integrative problem-centered metaframeworks therapy I: core concepts and hypothesizing

Over the last 20 years psychotherapy and family therapy have been inundated with a plethora of empirically validated treatments for particular disorders. That trend will increase. Psychotherapists will increasingly be exhorted and ultimately required to integrate empirical data and multicultural competence into their practice. Additionally, individual psychotherapy's default dominance of psychotherapeutic discourse needs to integrate and come to theoretical and clinical terms with the implications of the growing body of research demonstrating the validity and value of a multisystemic perspective. This article (and its companion article) presents a comprehensive, integrative, multisystemic, and empirically informed psychotherapeutic perspective to help therapists and psychotherapy trainers successfully address these challenges-Integrative Problem Centered Metaframeworks (IPCM) Therapy. This first article presents and illustrates IPCM's theoretical foundation, core concepts, and "case formulating" components. It delineates a Blueprint for the practice and teaching of 21st century psychotherapists who can meld science and art into best practice.     

Breast Cancer as Trauma: Posttraumatic Stress and Posttraumatic Growth

Diagnosis and treatment of cancer has been associated with both posttraumatic stress disorder (PTSD) symptoms and posttraumatic growth (PTG). This cross-sectional study sought to assess the frequency, common predictors, and interrelationships of PTSD symptoms and PTG in breast cancer survivors (n = 65). In this sample, symptoms of PTSD and reports of PTG were common and were not significantly related to one another. Greater social constraints on talking about breast cancer and perception of cancer as a traumatic stressor were associated with greater PTSD symptomatology. Younger age and perception of cancer as a traumatic stressor were associated with greater PTG. Findings suggest the central role of subjective appraisal in adjustment to cancer. Psychosocial interventions should be sensitive to the potential for PTG, both in treatment design and in assessment of outcomes.     

Two Puzzles for Deontologists: Life-Prolonging Killings and the Moral Symmetry Between Killing and Causing a Person to be Unconscious

Some form of agent-relative constraint against the killing of innocent personsis a central principle in deontological moraltheories. In this article I make two claimsabout this constraint. First, I argue that somekillings of innocents performed incircumstances usually not taken to exculpatethe killer are not even pro tanto wrong.Second, I contend that either there is noagent-relative constraint against the killingof innocents or this constraint has a verydifferent shape from that which deontologistsnormally take it to have. My defence of theseclaims rests on two propositions. First, inkilling someone one may actually prolong thatperson's life. Roughly, life-prolongingkillings are possible, because to kill someoneis to perform an act that causes someone'sdeath and it might well be true that, had onenot performed this act, one's ``victim' wouldhave died earlier. Second, all other thingsbeing equal, killing and causing a person to beunconscious are morally equivalent. Both ofthese propositions are defended in thearticle.