Probing expert anticipation with the temporal occlusion paradigm: Experimental investigations of some methodological issues

Copyright @ 2005 Human KineticsTwo experiments were conducted to examine whether the conclusions drawn regarding the timing of anticipatory information pick-up from temporal occlusion studies are influenced by whether (a) the viewing period is of variable or fixed duration and (b) the task is a laboratory-based one with simple responses or a natural one requiring a coupled, interceptive movement response. Skilled and novice tennis players either made pencil-and-paper predictions of service direction (Experiment 1) or attempted to hit return strokes (Experiment 2) to tennis serves while their vision was temporally occluded in either a traditional progressive mode (where more information was revealed in each subsequent occlusion condition) or a moving window mode (where the visual display was only available for a fixed duration with this window shifted to different phases of the service action). Conclusions regarding the timing of information pick-up were generally consistent across display mode and across task setting lending support to the veracity and generalisability of findings regarding perceptual expertise in existing laboratory-based progressive temporal occlusion studies.This study is funded by the Australian Institute of Sport Tennis program

An Africa strategy for IIMI

Irrigation management / Policy / Africa

A novel training tool for batters to watch the ball

postprintConference of Science, Medicine & Coaching in Cricket 2010, Queensland, Australia, 1-3 June 2010. In Conference Proceedings, 2010, p. 32-3

Anticipation and transfer of expert pattern perception

Conference Theme: Meeting New Challenges and Bridging Cultural Gaps in Sport and Exercise PsychologyINTRODUCTION: When an observer views a moving object that is abruptly halted, the human perceptual system continues to extrapolate the object’s movement, predicting it’s likely pathway and misrepresenting the final stopping point as being further along the original trajectory (Freyd & Johnson, 1987). This extrapolation of the temporal features is typically referred to as “representational momentum” (Freyd, 1987; Freyd & Finke, 1984; Intraub, 2002). It has been suggested that this phenomenon occurs because participants anticipate the trajectory of the object and remember that object by integrating its predicted motion with perceptions of its implied acceleration and velocity (Didierjean & Marmèche, 2005; Finke, Freyd, & Shyi, 1986). This anticipatory trace is then stored in memory and can be accessed for subsequent recall and recognition …postprin

Synthesis and Coordination Compounds of A Bis(Imino)Acenaphthene (Bian)-Supported N-Heterocyclic Carbene

The bis(imino)acenaphthene-supported N-heterocyclic carbene IPr(BIAN) has been prepared by deprotonation of the precursor imidazolium chloride. Treatment of IPr(BIAN) imidazolium chloride with Ag(2)O afforded the silver complex [IPr(BIAN)]AgCl which can be converted into the corresponding gold complex [IPr(BIAN)]AuCl by reaction with (tht)AuCl (tht = tetrahydrothiophene). The iridium complex [IPr(BIAN)]Ir(COD)Cl was prepared by reaction of the imidazolium chloride with KO(t)Bu and [Ir(COD)Cl](2) and subsequently converted to the carbonyl complex [IPr(BIAN)]Ir(CO)(2)Cl by exposure to an atmosphere of CO. All new compounds were characterized by single-crystal X-ray diffraction, multinuclear NMR, MS and HRMS data.Robert A. Welch Foundation F-0003National Science Foundation 0741973Chemistr

The contributions of central and peripheral vision to expertise in basketball: How blur helps to provide a clearer picture

The main purpose of this study was to examine the relative roles of central and peripheral vision when performing a dynamic forced-choice task. We did so by using a gaze-contingent display with different levels of blur in an effort to (a) test the limit of visual resolution necessary for information pick-up in each of these sectors of the visual field and, as a result, to (b) develop a more natural means of gaze-contingent display using a blurred central or peripheral visual field. The expert advantage seen in usual whole field visual presentation persists despite surprisingly high levels of impairment to central or peripheral vision. Consistent with the well-established central/peripheral differences in sensitivity to spatial frequency, high levels of blur did not prevent better-than-chance performance by skilled players when peripheral information was blurred, but they did affect response accuracy when impairing central vision. Blur was found to always alter the pattern of eye movements before it decreased task performance. The evidence accumulated across the 4 experiments provides new insights into several key questions surrounding the role that different sectors of the visual field play in expertise in dynamic, time-constrained tasks

Increasing difficulty but not decreasing performance: maintained interception with increments in visual blur

Conference Theme: Meeting New Challenges and Bridging Cultural Gaps in Sport and Exercise PsychologyINTRODUCTION: In an earlier study on the relationship between visual blur and interceptive skill (Mann, Ho, De Souza, Watson, & Taylor, 2007) it was observed that interceptive performance can be maintained despite the introduction of significant refractive visual blur. Mann et al. found that contact lenses simulating legally-blind levels of short-sightedness were required (6/60 or 20/200 acuity) before any subjectively assessed decrease in skilled performance could be measured when intercepting balls pitched by a projection machine in the sport of cricket. Several of the participants reported a preference for taking part with low levels of visual blur as a means of focusing concentration and visual attention, raising the possibility that rather than decreasing performance, training with blurred vision may provide an opportunity to enhance skill acquisition. The aim of this study was to extend the protocol of Mann et …postprin

Deceptive body movements reverse spatial cueing in soccer

This article has been made available through the Brunel Open Access Publishing Fund.The purpose of the experiments was to analyse the spatial cueing effects of the movements of soccer players executing normal and deceptive (step-over) turns with the ball. Stimuli comprised normal resolution or point-light video clips of soccer players dribbling a football towards the observer then turning right or left with the ball. Clips were curtailed before or on the turn (-160, -80, 0 or +80 ms) to examine the time course of direction prediction and spatial cueing effects. Participants were divided into higher-skilled (HS) and lower-skilled (LS) groups according to soccer experience. In experiment 1, accuracy on full video clips was higher than on point-light but results followed the same overall pattern. Both HS and LS groups correctly identified direction on normal moves at all occlusion levels. For deceptive moves, LS participants were significantly worse than chance and HS participants were somewhat more accurate but nevertheless substantially impaired. In experiment 2, point-light clips were used to cue a lateral target. HS and LS groups showed faster reaction times to targets that were congruent with the direction of normal turns, and to targets incongruent with the direction of deceptive turns. The reversed cueing by deceptive moves coincided with earlier kinematic events than cueing by normal moves. It is concluded that the body kinematics of soccer players generate spatial cueing effects when viewed from an opponent's perspective. This could create a reaction time advantage when anticipating the direction of a normal move. A deceptive move is designed to turn this cueing advantage into a disadvantage. Acting on the basis of advance information, the presence of deceptive moves primes responses in the wrong direction, which may be only partly mitigated by delaying a response until veridical cues emerge

Risk analysis in animal health: threat or opportunity for Africa?

Risk analysis originated in the aerospace industry following the loss of life due to a fire on Apollo flight AS-204 in 1967. The tool was later developed in the nuclear industry for the reactor safety. It reached the animal health sector through the Sanitary and Phytosanitary (SPS) agreement signed in 1994 during the Marrakech agreement of the General Agreement on Tariffs and Trade (GATT). The SPS agreement entered into force with the establishment of the World Trade Organization (WTO) on 1 January 1995. The SPS agreement recognises the World Organisation for Animal Health (OIE) as the relevant international organization entrusted with the development of import risk analysis techniques in animal health. The (appropriate) level of protection that countries imposed to avoid ingress of highly infectious diseases through restriction of imports had to be based on scientific principles (i.e. risk analysis). Development of risk analysis studies requires available data, teamwork, as well as specific skills. One can understand the impact of such studies in terms of access to market for specific commodities and in terms of protection against transboundary diseases introduction. We assessed the extent to which risk analysis is used in Africa in compliance with OIE standards and guidelines, through a study based on two approaches. A questionnaire evaluating the capacity, capacity building and the risk assessment studies produced or received was carried out through all the African countries. In parallel, the risk analysis section of evaluation reports produced by OIE in almost all African countries as part of the Performance of Veterinary Services (PVS) pathway was analysed. Results allowed us to draw a picture of the situation in Africa regarding the use of this very technical tool as well as to formulate some recommendations to improve the sanitary protection and the access of African countries to international markets. (Texte intégral