32 research outputs found

    Auditory reafferences: The influence of real-time feedback on movement control

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    © 2015 Kennel, Streese, Pizzera, Justen, Hohmann and Raab. Auditory reafferences are real-time auditory products created by a person's own movements. Whereas the interdependency of action and perception is generally well studied, the auditory feedback channel and the influence of perceptual processes during movement execution remain largely unconsidered. We argue that movements have a rhythmic character that is closely connected to sound, making it possible to manipulate auditory reafferences online to understand their role in motor control. We examined if step sounds, occurring as a by-product of running, have an influence on the performance of a complex movement task. Twenty participants completed a hurdling task in three auditory feedback conditions: a control condition with normal auditory feedback, a white noise condition in which sound was masked, and a delayed auditory feedback condition. Overall time and kinematic data were collected. Results show that delayed auditory feedback led to a significantly slower overall time and changed kinematic parameters. Our findings complement previous investigations in a natural movement situation with non-artificial auditory cues. Our results support the existing theoretical understanding of action-perception coupling and hold potential for applied work, where naturally occurring movement sounds can be implemented in the motor learning processes

    Long-term effects of acoustic reafference training (ART).

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    This is an Accepted Manuscript of an article published by Taylor & Francis in European Journal of Sport Science on 09 oct 2017, available online: http://www.tandfonline.com/10.1080/17461391.2017.1381767 In sport visual feedback is often used to enhance performance, mostly neglecting the auditory modality. However, athletes produce natural sounds when they move (acoustic reafferences) which they perceive and use to control their movements. We examined the short- and long-term effects of a training intervention on a complex movement by using acoustic reafferences. Natural step sounds produced during hurdling were recorded and played back to the participants immediately before each trial, with an increase (fast group), decrease (slow group), or no manipulation (control group) in the tempo. All groups increased their hurdling performance regarding overall running time, with the slow group showing the best performance development. After a 10-week retention, the fast and slow group further increased performance, whereas the control group declined. The repeated experience with acoustic information associated with the rhythmic pattern of hurdling may have helped developing a cognitive representation of that movement, especially regarding long-term effects

    Data for: Digestate treatment with algae-bacteria consortia: a field pilot-scale experimentation in a sub-optimal climate area

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    Raw data of chemical and microbiological data from raceway and bubble column monitoring campaig

    How Effective Is a Video Review System in Soccer?

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    For the first time in soccer history, FIFA allowed additional technology to support referees’ decisions at the World Cup 2014. Debates are pursued regarding the implementation of a video review system. The present study aimed to take up this debate and investigate if different visual perspectives and the use of slow motion influence referees’ decisions. One hundred nine (inter)nationally licensed referees (Mage 1⁄4 30.8 years) took part in an online video test and judged 48 video clips on foul decisions in the penalty box. Each incident was randomly shown 4 times (3 different perspectives and 1 slow motion). Perspective A showed the typical television broadcast view, Perspective B showed the assistant, and Perspective C showed the additional assistant referees’ view. After each video clip, the referees indicated if the situation should be categorized as no foul, foul, yellow card, or red card. Decision accuracy (DA) was significantly higher for the slow-motion condition (M 1⁄4 69.8%, SD 1⁄4 13.55) com- pared with the real-time condition (M 1⁄4 64.98%, SD 1⁄4 13.16), t(109) 1⁄4 5.07, p , .01, d 1⁄4 0.48. Referees were most accurate in Perspectives A (M 1⁄4 63.53%, SD 1⁄4 15.37) and C (M 1⁄4 65.29%, SD 1⁄4 12.39), signifi- cantly better than Perspective B (M 1⁄4 59.10%, SD 1⁄4 12.85), F(2, 107) 1⁄4 16.81, p , .01, h2 1⁄4 .24. The highest DA was obtained at the 3rd viewing, F(3, 105) 1⁄4 5.38, p , .01, h2 1⁄4 .13. The results show that referees benefit from slow-motion video displays and repeated viewings, with a threshold after 3 viewings. The results also suggest that a video review system should include different video perspectives, with the broadcast and the close-up view behind the goal showing the greatest effects. These results seem interesting, considering current discussions about additional technology in soccer

    The video review system in association football: implementation and effectiveness for match officials and referee education

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    Rationale: There has been continued debate in the world of sport over the effectiveness and merits of video technology as a decision aid for sports officials. In 2018, the video assistant referee (VAR) was introduced in association football. The aim of this study was to investigate the influence and effectiveness of a video review system for match officials and their education in association football. Design: Using an online video test, qualified football referees (N=109) categorized contentious penalty decisions across 48 short videos. Manipulating the number of viewings, playback speed and visual perspectives, referee decision accuracy and decision confidence were assessed. Findings: The results show an overall decision accuracy of 65.69%. Additionally, the results reveal significant differences between the different review conditions; particularly, improvements in accuracy for an increased number of viewings, a slowed playback speed and alternate visual perspectives. Practical implications: The results provide a greater understanding of the effects a decision review system in association football has on the decision accuracy and confidence of referees and further contribute to the use of video review for referee education. Research contribution: The current study extends research on the effects of different viewing perspectives, repeated viewings, and slower video speed on visual accuracy and the quality of cognitive-evaluative processes

    Data for: Digestate treatment with algae-bacteria consortia: a field pilot-scale experimentation in a sub-optimal climate area

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    Raw data of chemical and microbiological data from raceway and bubble column monitoring campaignTHIS DATASET IS ARCHIVED AT DANS/EASY, BUT NOT ACCESSIBLE HERE. TO VIEW A LIST OF FILES AND ACCESS THE FILES IN THIS DATASET CLICK ON THE DOI-LINK ABOV

    Comparison of the performance and microbial community structure of two outdoor pilot-scale photobioreactors treating digestate

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    This study aimed at examining and comparing the nutrient removal efficiency, biomass productivity and microbial community structure of two outdoor pilot-scale photobioreactors, namely a bubble column and a raceway pond, treating the liquid fraction of an agricultural digestate. Bacterial and eukaryotic communities were characterized using a metabarcoding approach and quantitative PCR. The abundance, composition, diversity, and dynamics of the main microbes were then correlated to the environmental conditions and operational parameters of the reactors. Both photobioreactors were dominated either by Chlorella sp. or Scenedesmus sp. in function of temperature, irradiance and the nitrogen compounds derived by nitrification. Other species, such as Chlamydomonas and Planktochlorella, were sporadically present, demonstrating that they have more specific niche requirement. Pseudomonas sp. always dominated the bacterial community in both reactors, except in summertime, when a bloom of Calothrix occurred in the raceway pond. In autumn, the worsening of the climate conditions decreased the microalgal growth, promoting predation by Vorticella sp. The study highlights the factors influencing the structure and dynamics of the microbial consortia and which ecological mechanisms are driving the microbial shifts and the consequent reactor performance. On these bases, control strategies could be defined to optimize the management of the microalgal-based technologies

    Performance Psychology: Perception, Action, Cognition, and Emotion

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    © 2016 Elsevier Inc. All rights reserved.This book integrates findings from across domains in performance psychology to focus on core research on what influences peak and non-peak performance. The book explores basic and applied research identifying cognition-action interactions, perception-cognition interactions, emotion-cognition interactions, and perception-action interactions. The book explores performance in sports, music, and the arts both for individuals and teams/groups, looking at the influence of cognition, perception, personality, motivation and drive, attention, stress, coaching, and age. This comprehensive work includes contributions from the US, UK, Canada, Germany, and Australia. Integrates research findings found across domains in performance psychology. Includes research from sports, music, the arts, and other applied settings. Identifies conflicts between cognition, action, perception, and emotion. Explores influences on both individual and group/team performance. Investigates what impacts peak performance and error production

    Schiedsrichterbeeinflussung durch gezielte LautĂ€ußerungen

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    Lex H, Kurtes M, Pizzera A, Schack T. Schiedsrichterbeeinflussung durch gezielte LautĂ€ußerungen. In: Deutscher Fußball-Bund, ed. 2. DFB-Wissenschafts-Kongress 2013. Frankfurt a.M.: Philippka; 2013: 212
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