234 research outputs found

    Helsen, Gilis and Weston (2006) err in testing the optical error hypothesis

    Get PDF
    In this commentary, we react to the recent study by Helsen, Gilis and Weston (2006) on judging offside in football. Helsen et al. claim that their data falsify the optical error hypothesis presented by Oudejans et al. (2000). However, as we will elucidate here, they misinterpret this hypothesis and present a data set that is seriously flawed, and hence not suited to test it. Therefore, their conclusions regarding the optical error hypothesis are in error

    PsycINFO classification: 2300; 2323

    Get PDF
    Abstract Most research on visual search in aiming at far targets assumes preprogrammed motor control implying that relevant visual information is detected prior to the final shooting or throwing movements. Eye movement data indirectly support this claim for stationary tasks. Using the basketball jump shot as experimental task we investigated whether in dynamic tasks in which the target can be seen until ball release, continuous, instead of preprogrammed, motor control is possible. We tested this with the temporal occlusion paradigm: 10 expert shooters took shots under four viewing conditions, namely, no vision, full vision, early vision (vision occluded during the final AE350 ms before ball release), and late vision (vision occluded until these final AE350 ms). Late-vision shooting appeared to be as good as shooting with full vision while early-vision performance was severely impaired. The results imply that the final shooting movements were controlled by continuous detection and use of visual information until ball release. The data further suggest that visual and movement control of aiming at a far target develop in close correspondence with the style of execution. Ó 2002 Elsevier Science B.V. All rights reserved

    Training with anxiety: short- and long-term effects on police officers’ shooting behavior under pressure

    Get PDF
    We investigated short- and long-term effects of training with anxiety on police officers’ shooting behavior under pressure. Using a pretest, posttest, and retention test design, 27 police officers executed a shooting exercise against an opponent that did (high anxiety) or did not (low anxiety) shoot back using colored soap cartridges. During the training sessions, the experimental group practiced with anxiety and the control group practiced without anxiety. At the pretest, anxiety had a negative effect on shot accuracy for both groups. At the posttest, shot accuracy of the experimental group no longer deteriorated under anxiety, while shot accuracy of the control group was still equally affected. At the retention test, 4 months after training, positive results for the experimental group remained present, indicating that training with anxiety may have positive short- and long-term effects on police officers’ shot accuracy under pressure. Additional analyses showed that these effects are potentially related to changes in visual attention on task-relevant information

    The impact of the COVID-19 pandemic on European police officers: Stress, demands, and coping resources

    Get PDF
    Purpose: Facing the COVID-19 pandemic, police officers are confronted with various novel challenges, which might place additional strain on officers. This mixed-method study investigated officers’ strain over a three- month-period after the lockdown. Methods: In an online survey, 2567 police officers (77% male) from Austria, Germany, Switzerland, the Netherlands, and Spain participated at three measurement points per country in spring, 2020. Three-level growth curve models assessed changes in strain and its relation to stressor appraisal, emotion regulation, and pre- paredness through training. To add context to the findings, free response answers about officers’ main tasks, stressors, and crisis measures were coded inductively. Results: On average, officers seemed to tolerate the pandemic with slight decreases in strain over time. Despite substantial variance between countries, 66% of the variance occurred between individuals. Sex, work experience, stressor appraisal, emotion regulation, and preparedness significantly predicted strain. Risk of infection and deficient communication emerged as main stressors. Officers’ reports allowed to derive implications for governmental, organizational, and individual coping strategies during pandemics. Conclusion: Preparing for a pandemic requires three primary paths: 1) enacting unambiguous laws and increasing public compliance through media communication, 2) being logistically prepared, and 3) improving stress regulation skills in police training

    An analysis of teachers’ instructions and feedback at a contemporary dance university

    Get PDF
    BackgroundGiven the demands posed by excessive practice quantities in modern dance, physical and mental health can be compromised. Therefore, there is a need to consider how quality of practice may be improved and possibly even reduce training times. Sports literature has shown that instructions and feedback given by coaches can have an effect on the quality of training and influence self-regulation and the performance of athletes. However, currently little is known about the use of instructions and feedback by dance teachers. The aim of the current study was, therefore, to examine the type of instructions and feedback given by dance teachers during various dance classes.MethodsA total of six dance teachers participated in this study. Video and audio recordings were made of six dance classes and two rehearsals at a contemporary dance university. The dance teacher’s coaching behavior was analyzed using the modified Coach Analysis and Intervention System (CAIS). Additionally, feedback and instructions were also examined in terms of their corresponding focus of attention. Absolute numbers, as well as times per minute (TPM) rates were calculated for each behavior before, during, and after an exercise. Absolute numbers were also used to calculate ratios of positive-negative feedback and open-closed questions.ResultsMost feedback comments were given after an exercise (472 out of 986 total observed behaviors). Improvisation had the highest positive-negative feedback ratio (29) and open-closed questions ratio (1.56). Out of the focus of attention comments, internal focus of attention comments were used most frequently (572 out of 900).Discussion/conclusionThe results make clear that there is a large variability in instructions and feedback over teachers and classes. Overall, there is room for improvement toward a higher positive-negative feedback ratio, a higher open-closed question ratio and producing more comments eliciting an external focus of attention

    An Analysis of Pedestrian Waiting Time at Uncontrolled Crosswalks Using Discrete Choice Model

    Get PDF
    A study of pedestrians crossing behavior is conducted at an uncontrolled mid-block crosswalk in Istanbul Turkey, to model the pedestrians waiting time, related to their behavior for making the crossing decision. This article focused on the issues encountered in the modeling of the operational behavior of pedestrians. The discrete choice framework is used because of its capacity to deal with individuals’ choice behavior. Pedestrians waiting time is classified into three levels, including low, medium, and high levels based on the level of service of pedestrians waiting time. The pedestrians’ behavior prediction has been improved by analyzing, taking into account three levels for pedestrian behavior

    Presence of Epstein-Barr virus latency type III at the single cell level in post- transplantation lymphoproliferative disorders and AIDS related lymphomas

    Get PDF
    AIMS: To investigate the expression pattern of Epstein-Barr virus (EBV) latent genes at the single cell level in post-transplantation lymphoproliferative disorders and acquired immunodefiency syndrome (AIDS) related lymphomas, in relation to cellular morphology. METHODS: Nine post-transplantation lymphoproliferative disorders and three AIDS related lymphomas were subjected to immunohistochemistry using monoclonal antibodies specific for EBV nuclear antigen 1 (EBNA1) (2H4), EBNA2 (PE2 and the new rat anti-EBNA2 monoclonal antibodies 1E6, R3, and 3E9), and LMP1 (CS1-4 and S12). Double staining was performed combining R3 or 3E9 with S12. RESULTS: R3 and 3E9 anti-EBNA2 monoclonal antibodies were more sensitive than PE2, enabling the detection of more EBNA2 positive lymphoma cells. Both in post-transplantation lymphoproliferative disorders and AIDS related lymphomas, different expression patterns were detected at the single cell level. Smaller neoplastic cells were positive for EBNA2 but negative for LMP1. Larger and more blastic neoplastic cells, sometimes resembling Reed-Sternberg cells, were LMP1 positive but EBNA2 negative (EBV latency type II). Morphologically intermediate neoplastic cells coexpressing EBNA2 and LMP1 (EBV latency type III), were detected using R3 and 3E9, and formed a considerable part of the neoplastic population in four of nine post-transplantation lymphoproliferative disorders and two of three AIDS related lymphomas. All samples contained a subpopulation of small tumour cells positive exclusively for Epstein-Barr early RNA and EBNA1. The relation between cellular morphology and EBV expression patterns in this study was less pronounced in AIDS related lymphomas than in post-transplantation lymphoproliferative disorders, because the AIDS related lymphomas were less polymorphic than the post-transplantation lymphoproliferative disorders. CONCLUSIONS: In post-transplantation lymphoproliferative disorders and AIDS related lymphomas, EBV latency type III can be detected by immunohistochemistry in a subpopulation of tumour cells using sensitive monoclonal antibodies R3 and 3E9. Our data suggest that EBV infected tumour cells in these lymphomas undergo gradual changes in the expression of EBV latent genes, and that these changes are associated with changes in cellular morphology

    Affective stimulus properties influence size perception and the Ebbinghaus illusion

    Get PDF
    In the New Look literature of the 1950s, it has been suggested that size judgments are dependent on the affective content of stimuli. This suggestion, however, has been ‘discredited’ due to contradictory findings and methodological problems. In the present study, we revisited this forgotten issue in two experiments. The first experiment investigated the influence of affective content on size perception by examining judgments of the size of target circles with and without affectively loaded (i.e., positive, neutral, and negative) pictures. Circles with a picture were estimated to be smaller than circles without a picture, and circles with a negative picture were estimated to be larger than circles with a positive or a neutral picture confirming the suggestion from the 1950s that size perception is influenced by affective content, an effect notably confined to negatively loaded stimuli. In a second experiment, we examined whether affective content influenced the Ebbinghaus illusion. Participants judged the size of a target circle whereby target and flanker circles differed in affective loading. The results replicated the first experiment. Additionally, the Ebbinghaus illusion was shown to be weakest for a negatively loaded target with positively loaded and blank flankers. A plausible explanation for both sets of experimental findings is that negatively loaded stimuli are more attention demanding than positively loaded or neutral stimuli

    A little less conversation; a little more (relational) action please. A fictional dialogue of integrating theory into coaching practice

    Get PDF
    This paper presents a fictional dialogue that supports the application of theory in coaching pedagogy. The “constraints led approach” (CLA) is promoted throughout in conversation form, providing pedagogic solutions in response to the decaying performance levels of a fictitious football team. This deterioration is linked to “poor” coaching and the merits of a more innovative pedagogy through a discussion between “manager” and “coach” are presented. Recommendations are made with particular reference to developing games players, who are skilful, perceptive and intelligent, through being able to initiate and modify actions in dynamic contexts. Through substantiating a platform for both changing perceptions about coaching practice and challenging assumptions about learning, such accessibility to unfamiliar knowledge(s) can allow coaches to clearly consider possibilities for change. It is further suggested that through embracing the use of novel methodologies to consider unfamiliar theoretical territory, this demonstrates a responsibility to close and not widen a theory-practice gap. By presenting Mark (coach) as “theoretical negotiator”, this paper emphasises the potency of experimenting with nuanced methods that can be part of an academic process to help shape more theoretically literate coaches
    corecore