3,972 research outputs found
Stable implicit motor processes despite aerobic locomotor fatigue
No full textImplicit processes almost certainly preceded explicit processes in our evolutionary history, so they are likely to be more resistant to disruption according to the principles of evolutionary biology [Reber, A. S. (1992). The cognitive unconscious: An evolutionary perspective. Consciousness and Cognition, 1, 93-133.]. Previous work (e.g., [Masters, R. S. W. (1992). Knowledge, (k)nerves and know-how: The role of explicit versus implicit knowledge in the breakdown of a complex motor skill under pressure. British Journal of Psychology, 83, 343-358.]) has shown that implicitly learned motor skills remain stable under psychological pressure and concurrent cognitive demands, and recently [Poolton, J. M., Masters, R. S. W., & Maxwell, J. P. (2007). Passing thoughts on the evolutionary stability of implicit motor behaviour: Performance retention under physiological fatigue. Consciousness and Cognition, 16(2), 456-468.] showed that they also remain stable under conditions of anaerobic fatigue that would have significantly challenged the survival skills of our ancestors. Here we examine the stability of an implicitly learned motor skill under fatigue conditions that primarily tax a different physiological system (the aerobic system), but which have equally strong evolutionary connotations. Participants acquired a throwing task by means of an errorless (implicit) learning method or an errorful (explicit) method. Motor performance in the errorless condition, but not the errorful condition, remained stable following an exhaustive VO2 max. running test. Our findings replicate and extend the work of Poolton et al., providing further support for Reber's evolutionary distinction between implicit and explicit processes. © 2007 Elsevier Inc. All rights reserved.link_to_subscribed_fulltex
Conscious monitoring and control (reinvestment) in surgical performance under pressure.
No full textResearch 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
Self-consciousness, perceived evaluation, and performance of a continuous motor task
No full textAccording to some authors, highly self-conscious individuals are susceptible to performance breakdown in the presence of an evaluative audience (e.g., Maxwell, Masters, & Poolton, 2006), whereas other authors report less susceptibility (e.g., Baumeister, 1984). Previous studies have provided these contrasting results using discrete tasks. The aim of the current study was to ascertain whether self-consciousness is associated with changes to continuous task performance (simulated driving) in the presence and absence of an evaluative passenger, and to elucidate the direction of this relationship. Participants, classified as either high or low self-conscious (n = 14 in each group), performed seven 5-minute trials on a driving simulator. The first six trials (Practice Phase) were performed alone, whereas, the final trial (Observation Phase) was performed whilst observed. During the Practice Phase high self-conscious drivers were recorded engaging in riskier driving behaviours, relative to low self-conscious drivers. During the Observation Phase, high self-conscious drivers still displayed riskier driving behaviours than did low self-conscious drivers despite both groups' attempts to control the speed of their vehicles. The results imply that high trait self-consciousness, rather than low, appears to be associated with poorer task performance under both evaluative and non-evaluative conditions.link_to_subscribed_fulltex
Implicit motor learning promotes neural efficiency during laparoscopy.
No full textAn understanding of differences in expert and novice neural behavior can inform surgical skills training. Outside the surgical domain, electroencephalographic (EEG) coherence analyses have shown that during motor performance, experts display less coactivation between the verbal-analytic and motor planning regions than their less skilled counterparts. Reduced involvement of verbal-analytic processes suggests greater neural efficiency. The authors tested the utility of an implicit motor learning intervention specifically devised to promote neural efficiency by reducing verbal-analytic involvement in laparoscopic performance
Using EEG methodology to examine the effect of exercise induced fatigue on the direction of attention during motor skill performance
No full textExercise induced fatigue can have a negative impact on motor skill performance. While part of the decline is attributable to physiological factors that directly influence the coordination of movement, psychological factors may also contribute. Typically, motor learning environments encourage the accumulation of task-relevant declarative knowledge, which can be depended on to consciously support performance. The literature suggests that skills learnt in this way are vulnerable to demanding performance environments, including those in which the performer is fatigued. Recent empirical work has demonstrated that ‘implicit’ motor learning environments, devised to limit declarative knowledge buildup and/or dependence on working memory, promote resilient skill performance even after exhaustive fatigue protocols. Such findings imply that dependence on declarative knowledge to support motor skill execution may be a limiting factor under physiologically fatigue. However, it remains unclear the effect fatigue has on attentional resources, such as working memory.
Using established experimental paradigms and EEG methodology, a research project was designed to investigate. Two explanations were considered: (1) fatigue distracts attention away from the control of movement or (2) fatigue directs attention to the skill, which interferes with automated control of the movement. In this study novice participants were allowed to freely accumulate declarative knowledge before completing a targeted muscle-fatigue protocol. A probe response paradigm assessed participants’ ability to recall the position of movement at the time a tone sounded, under the assumption that better recall reflects skill-focused attention. Neural activity was monitored by wireless EEG technology. Neural co-activation (or coherence) between brain regions associated with motor planning (Fz or F3) and with verbal-analytical processing (T3) has been suggested to reflect conscious control of motor skills. Therefore, a fatigue induced increase in T3-F3 coherence can be interpreted as increased conscious involvement in movement control, whereas, a decrease suggests a shift of attention away from movement control. The data collected suggests that to some extent fatigue raises visual-spatial and verbal-analytical contributions to motor control, but highlights methodological issues and limitations of the work.published_or_final_versionHuman PerformanceMasterMaster of Philosoph
Examining the influence of marginally modified constraints on motor behaviour
No full textThe thesis examines the influence of visual misperceptions of the primary environmental constraints related to motor behaviour, and explores whether motor adaptation can be caused implicitly by introducing systematic, undetectable changes in key constraints in the performance environment. The first two experiments (Chapter 2) were conducted to determine if a simple manipulation of the height of the uprights can cause participants to perceive the dimensions of the rugby goalposts differently. The findings support the existence of a rugby goalpost illusion. Misperceptions of the dimensions of the goalposts may influence decisions about where to place the ball when converting a try. In Chapter 3, a series of experiments tested this hypothesis both in a laboratory setting and in real life games. Experiment 3 showed that narrow goalposts caused kickers to place the ball further from the try-line than wide goalposts. Furthermore, misperceptions of the uprights width induced by the rugby posts illusion caused kickers to place the ball differently when making kicks (Experiment 4). By introducing pitch-markings in Experiment 5, we tested whether the effect of the illusion is moderated by use of familiar cues in the environment. An observational study (Experiment 6) suggested that the influence of the rugby posts illusion, intimated in our experimental work, is not evident in real life. Both Chapters 4 and 5 were designed to examine whether very subtle changes in constraints in the environment can be used specifically to induce implicit motor learning. In Chapter 4, the smallest detectable difference between two levels of sensory stimulus was determined for simple line drawings representative of rugby goalpost uprights (Experiment 7) or crossbars (Experiment 8). The findings from Chapter 5 suggested that (implicit) motor adaptations might be caused by gradual incremental changes in environmental constraints.published_or_final_versionHuman PerformanceDoctoralDoctor of Philosoph
The SSC of the Generalised Jahangir’s Graph Jm,k and its Algebraic Characterizations
No full textIn this article, we present important combinatorial and algebraicproperties of spanning simplicial complex (SSC) of the generalised Jahangir’sgraph Jm,k. We describe the relation to find f−vectors associatedto Δs(Jm,k) and determine the Hilbert series for the SR-ring KΔs(Jm,k).In the end, we present the associated primes of the facet ideal IF(Δs(Jm,k))and the Cohen-Macaulay characterization of the SR-ring of Δs(Jm,k).AMS (MOS) Subject Classification Codes: Primary 13-P10, Secondary 13-F20, 13-C14, 13-H10.Corresponding Author: Agha KashifKey Words: Simplicial Complexes, f-vectors, Spanning Trees, Face Ring, Hilbert Series, CohenMacaulay
To <i>JM</i> on Its 75th Anniversary
No full text This article discusses how Journal of Marketing ( JM) has influenced marketing science and practice by publishing articles on substantive topics relevant to customers, managers, organizations, markets, and society. The journal's 75th anniversary coincides with the 50th anniversary of the Marketing Science Institute (MSI). Frequently, JM and MSI have collaborated to address important substantive marketing issues identified in MSI's Research Priorities. The author highlights seminal articles on brand equity; business-to-business marketing (including sales force management); connecting marketing information, metrics, and strategy; consumer behavior; innovation, new product development. and product management; marketing orientation and capabilities; and market research, methodology and services. She also draws attention to articles that have won the Sheth Foundation/ JM Award and the H. Paul Root Award. The article describes how JM‘s knowledge dissemination is amplified by powerful social network effects. Ideas in JM articles diffuse through the business community, influencing the mind-set of managers worldwide. </jats:p
JM-20, a Benzodiazepine-Dihydropyridine Hybrid Molecule, Inhibits the Formation of Alpha-Synuclein-Aggregated Species
No full text\ua9 2022, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.Studies showed that JM-20, a benzodiazepine-dihydropyridine hybrid molecule, protects against rotenone and 6-hydroxydopamine neurotoxicity. However, its protective effects against cytotoxicity induced by endogenous neurotoxins involved in Parkinson’s disease (PD) pathogenesis have never been investigated. In this study, we evaluated the ability of JM-20 to inhibit alpha-synuclein (aSyn) aggregation. We also evaluated the interactions of JM-20 with aSyn by molecular docking and molecular dynamics and assessed the protective effect of JM-20 against aminochrome cytotoxicity. We demonstrated that JM-20 induced the formation of heterogeneous amyloid fibrils, which were innocuous to primary cultures of mesencephalic cells. Moreover, JM-20 reduced the average size of aSyn positive inclusions in H4 cells transfected with SynT wild-type and synphilin-1-V5, but not in HEK cells transfected with synphilin-1-GFP. In silico studies showed the interaction between JM-20 and the aSyn-binding site. Additionally, we showed that JM-20 protects SH-SY5Y cells against aminochrome cytotoxicity. These results reinforce the potential of JM-20 as a neuroprotective compound for PD and suggest aSyn as a molecular target for JM-20
Uterine transplantation: a promising surrogate to surrogacy?
No full textUterine transplantation: a promising surrogate to surrogacy?
Grynberg M1, Ayoubi JM, Bulletti C, Frydman R, Fanchin R.
Author information
Abstract
Infertility due to the inability of the uterus to carry a pregnancy ranks among the most unresolved issues in reproductive medicine. It affects millions of women worldwide who have congenital or acquired uterine affections, often requiring hysterectomy, and potentially represents a considerable fraction of the general infertile population. Patients suffering from severe uterine infertility are currently compelled to go through gestational surrogacy or adoption; both approaches, unfortunately, deprive them of the maternal experience of pregnancy and birth. Uterine transplantation represents an outstanding, yet complex, perspective to alleviating definitive uterine infertility. In the past decades, a number of scientific experiments conducted both in animals and women, focusing on uterine transplantation, have led to promising results. Collectively, these findings undoubtedly constitute a sound basis to clinically apply uterine transplantation in the near future. This paper is, however, an overview not only of the extent and limitations of accumulated scientific knowledge on uterine transplantation, but also its ethical implications, in an effort to define the actual place of such an approach among the therapeutic arsenal for alleviating infertility.
© 2011 New York Academy of Sciences
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