2,973 research outputs found

    The development of a culturally appropriate analogy for implicit motor learning in a Chinese population

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    Learning a motor skill by analogy can benefit performers because the movement that is developed has characteristics of implicit motor learning: namely, movement robustness under pressure and secondary task distraction and limited accrual of explicit knowledge (Liao & Masters, 2001). At an applied level the advantages are lost, however, if the heuristic that underpins the analogy conveys abstractions that are inappropriate for the indigenous culture. The aim of the current experiment was to redevelop Masters's (2000) right-angled-triangle analogy to accommodate abstractions appropriate for Chinese learners. Novice Chinese participants learned to hit table tennis forehands with topspin using either a redeveloped, culturally appropriate analogy (analogy learning) or a set of 6 instructions relevant to hitting a topspin forehand in table tennis (explicit learning). Analogy learners accrued less explicit knowledge of the movements underlying their performance than explicit learners. In addition, a secondary task load disrupted the performance of explicit learners but not analogy learners. These findings indicate that a culturally relevant analogy can bring about implicit motor learning in a Chinese population. © 2007 Human Kinetics, Inc.published_or_final_versio

    The influence of analogy learning on decision-making in table tennis: Evidence from behavioural data

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    Objectives: In sports it may be necessary for a performer to make a decision and execute a movement in close succession, or even concurrently. The manner in which a movement is controlled may impact on the degree to which the performer is able to combine decisions and movements effectively. Previous work has shown that if control of the movement has been acquired explicitly, with a high declarative knowledge content, dual-task conditions can be disruptive to performance of the movement. Previous work has also shown that, in contrast, if movement control is acquired by analogical instruction, with a low declarative knowledge content, motor performance is unaffected by dual-task conditions. It was, therefore, hypothesised that analogy learning will reduce the performance cost associated with processing motor responses while making high-complexity decisions. Methods: Participants learnt to hit a table tennis topspin forehand using either a single analogical instruction or a set of written instructions (explicit learning). Motor performance was assessed when decisions about the direction in which to hit the ball were either low in complexity or high in complexity. Results: Low-complexity decisions had no effect on motor performance in either condition. However, high-complexity decisions caused a relative performance deterioration in the Explicit condition, but not in the Analogy condition. Conclusions: These findings extend the implicit motor learning literature by highlighting the role of analogy learning in the complex interaction between decision-making and movement control in sport. © 2006 Elsevier Ltd. All rights reserved.postprin

    Attention and time constraints in performing and learning a table tennis forehand shot

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    This is a section on p. S95 of article 'Verbal and Poster: Motor Development, Motor Learning and Control, and Sport and Exercise Psychology' in Journal of Sport and Exercise Psychology, 2010, v.32, p.S36-S237published_or_final_versio

    Implicit motor learning and complex decision making in time-constrained environments

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    The cost-effectiveness of the implicit (procedural) knowledge that supports motor expertise enables surprisingly efficient performance when a decision and an action must occur in close temporal proximity. The authors argue that if novices learn the motor component of performance implicitly rather than explicitly, then they will also be efficient when they make a decision and execute an action in close temporal proximity. Participants (N = 35) learned a table tennis shot implicitly or explicitly. The authors assessed participants' motor performance and movement kinematics under conditions that required a concurrent low-complexity decision or a concurrent high-complexity decision about where to direct each shot. Performance was disrupted only for participants who learned explicitly when they made high-complexity decisions but not when they made low-complexity decisions. The authors conclude that implicit motor learning encourages cognitively efficient motor control more than does explicit motor learning, which allows performance to remain stable when time constraints call for a complex decision in tandem with a motor action. Copyright © 2008 Heldref Publications.published_or_final_versio

    Benefits of an external focus of attention: Common coding or conscious processing?

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    We conducted two experiments to assess the effect attentional focus has on learning a complex motor skill and subsequent performance under secondary task loading. Participants in Experiment 1 learnt a golf putting task (300 practice trials) with a single instruction to either focus on their hands (internal focus) or the movement of the putter (external focus). No group differences were evident during learning or retention. Differences between the groups were only apparent under secondary task load; the external group's performance remained robust, while the internal group suffered a drop in performance. Verbal protocols demonstrated that the internal group accumulated significantly more internal knowledge and more task-relevant knowledge in general than the external group. Experiment 2 was designed to establish whether greater internal focus knowledge or greater explicit rule build up in general was responsible for performance breakdown. Two groups were presented with a set of six internal or external rules. Again, no performance differences were found during learning or retention. During the secondary task, both groups experienced performance deterioration. It was concluded that accumulation of explicit rules to guide performance was responsible for the internal group's breakdown in performance under secondary task loading and may be responsible for some of the performance differences reported previously. © 2006 Taylor & Francis.postprin

    Emissions from the combustion of torrefied and raw biomass fuels in a domestic heating stove

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    Biomass (pellets, briquettes, logs) are a key contributor to many countries' strategies for decarbonising heat, particularly in domestic applications. The emissions from these small devices can be high and severely impact air quality, but their levels depend on the design, control, abatement and fuel options. This paper is concerned with the last case. A comparative study shows the emissions from a domestic wood stove for three biomass fuels and their torrefied counterparts. The fuels were burned in a multi-fuel stove along with two reload batches creating continuous combustion cycles: the initial cold start data is presented but not included in averaging and calculation of emission factors. Measurements were made using an FTIR instrument for carbon and nitrogen based gaseous emissions, particulates were measured using a smoke meter with micro-quartz filters as well as a size-selective impactor to obtain the particle size distribution. Particulate emissions were significantly reduced from the torrefied fuels and this is thought to be related to their pyrolysis fingerprint, which was investigated by pyrolysis-GC–MS. NOx was slightly reduced, despite increased fuel-N after torrefaction. In addition, the reduced moisture in the torrefied fuels decreases emissions of CO and CH4 because of increased time of flaming combustion

    Conscious monitoring and control (reinvestment) in surgical performance under pressure.

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    Research on intraoperative stressors has focused on external factors without considering individual differences in the ability to cope with stress. One individual difference that is implicated in adverse effects of stress on performance is "reinvestment," the propensity for conscious monitoring and control of movements. The aim of this study was to examine the impact of reinvestment on laparoscopic performance under time pressure

    Laser cooling of a diatomic molecule

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    It has been roughly three decades since laser cooling techniques produced ultracold atoms, leading to rapid advances in a vast array of fields. Unfortunately laser cooling has not yet been extended to molecules because of their complex internal structure. However, this complexity makes molecules potentially useful for many applications. For example, heteronuclear molecules possess permanent electric dipole moments which lead to long-range, tunable, anisotropic dipole-dipole interactions. The combination of the dipole-dipole interaction and the precise control over molecular degrees of freedom possible at ultracold temperatures make ultracold molecules attractive candidates for use in quantum simulation of condensed matter systems and quantum computation. Also ultracold molecules may provide unique opportunities for studying chemical dynamics and for tests of fundamental symmetries. Here we experimentally demonstrate laser cooling of the molecule strontium monofluoride (SrF). Using an optical cycling scheme requiring only three lasers, we have observed both Sisyphus and Doppler cooling forces which have substantially reduced the transverse temperature of a SrF molecular beam. Currently the only technique for producing ultracold molecules is by binding together ultracold alkali atoms through Feshbach resonance or photoassociation. By contrast, different proposed applications for ultracold molecules require a variety of molecular energy-level structures. Our method provides a new route to ultracold temperatures for molecules. In particular it bridges the gap between ultracold temperatures and the ~1 K temperatures attainable with directly cooled molecules (e.g. cryogenic buffer gas cooling or decelerated supersonic beams). Ultimately our technique should enable the production of large samples of molecules at ultracold temperatures for species that are chemically distinct from bialkalis.Comment: 10 pages, 7 figure

    A powerful intervention: general practitioners' use of sickness certification in depression

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    <b>Background</b> Depression is frequently cited as the reason for sickness absence, and it is estimated that sickness certificates are issued in one third of consultations for depression. Previous research has considered GP views of sickness certification but not specifically in relation to depression. This study aimed to explore GPs views of sickness certification in relation to depression.<p></p> <b>Methods</b> A purposive sample of GP practices across Scotland was selected to reflect variations in levels of incapacity claimants and antidepressant prescribing. Qualitative interviews were carried out between 2008 and 2009.<p></p> <b>Results</b> A total of 30 GPs were interviewed. A number of common themes emerged including the perceived importance of GP advocacy on behalf of their patients, the tensions between stakeholders involved in the sickness certification system, the need to respond flexibly to patients who present with depression and the therapeutic nature of time away from work as well as the benefits of work. GPs reported that most patients with depression returned to work after a short period of absence and that it was often difficult to predict which patients would struggle to return to work.<p></p> <b>Conclusions</b> GPs reported that dealing with sickness certification and depression presents distinct challenges. Sickness certificates are often viewed as powerful interventions, the effectiveness of time away from work for those with depression should be subject to robust enquiry
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