Linus Zeuwts

Mental fatigue impairs soccer-specific decision-making skill

ABSTRACT This study aimed to investigate the impact of mental fatigue on soccer-specific decision-making. Twelve well-trained male soccer players performed a soccer-specific decision-making task on two occasions, separated by at least 72 h. The decision-making task was preceded in a randomised order by 30 min of the Stroop task (mental fatigue) or 30 min of reading from magazines (control). Subjective ratings of mental fatigue were measured before and after treatment, and mental effort (referring to treatment) and motivation (referring to the decision-making task) were measured after treatment. Performance on the soccer-specific decision-making task was assessed using response accuracy and time. Visual search behaviour was also assessed throughout the decision-making task. Subjective ratings of mental fatigue and effort were almost certainly higher following the Stroop task compared to the magazines. Motivation for the upcoming decision-making task was possibly higher following the Stroop task. Decision-making accuracy was very likely lower and response time likely higher in the mental fatigue condition. Mental fatigue had unclear effects on most visual search behaviour variables. The results suggest that mental fatigue impairs accuracy and speed of soccer-specific decision-making. These impairments are not likely related to changes in visual search behaviour.

CUE USAGE IN VOLLEYBALL: A TIME COURSE COMPARISON OF ELITE, INTERMEDIATE AND NOVICE FEMALE PLAYERS

This study compared visual search strategies in adult female volleyball players of three levels. Video clips of the attack of the opponent team were presented on a large screen and participants reacted to the final pass before the spike. Reaction time, response accuracy and eye movement patterns were measured. Elite players had the highest response accuracy (97.50 ± 3.5%) compared to the intermediate (91.50 ± 4.7%) and novice players (83.50 ± 17.6%; p<0.05). Novices had a remarkably high range of reaction time but no significant differences were found in comparison to the reaction time of elite and intermediate players. In general, the three groups showed similar gaze behaviour with the apparent use of visual pivots at moments of reception and final pass. This confirms the holistic model of image perception for volleyball and suggests that expert players extract more information from parafoveal regions.

Hazard perception in young cyclists and adult cyclists

Child bicyclists are at greater risk to get involved in a traffic accident. Although hazard perception tests between inexperienced and experienced car drivers revealed significant differences in perceptual-cognitive skills, a similar test for bicyclists is not yet existent. Therefore this study aimed to compare visual search patterns and reaction times of child bicyclists and adult bicyclists utilizing a hazard perception test for cyclists. Seventy-five children and forty-one adults were presented with eleven video clips filmed from the perspective of the bicyclist. The participants were required to press a response button whenever they detected a hazardous situation. Children were found to have significantly delayed reaction times and time until the first fixation on the latent covert hazards compared to adults. The inefficient visual search patterns in children may be attributed to an immature visual system. However, the finding that children fixated later on the hazards and only responded to the covert latent hazards when they became salient indicate difficulties with identifying possible hazards. Altogether, the findings of this study suggest that childrens situation awareness is dependent upon experience too, and not just maturation. Therefore, implications for training young bicyclists will be discussed.

Development of cycling skills in 7 to 12-year-old children

ABSTRACT Objective: Cycling is a complex skill consisting of motor skills such as pedalling, braking, and steering. Because the ability to perform cycling skills is based on the age-related development of the child, experience and age-related reference values are of interest in light of customized testing and training. Methods: One hundred thirty-eight children from the second (7–8 years), fourth (9–10 years), and sixth (11–12 years) grades performed a practical bicycle test consisting of 13 test items with specific points of interest. Moreover, age at onset of cycling, cycling to and from school, independent mobility, and minutes cycling per week were estimated using a parental questionnaire. Results: It is found that cycling skills are strongly related to age with 11- to 12-year-old children outperforming 7- to 8-year-old children for 11 test items and 9- to 10-year-old children for 8 test items. Conclusions: Next to age, age at onset of cycling also contributed to cycling skills. Therefore, our results suggest that cycling skills are associated with physical and mental maturation. Subsequently, age-related reference values are provided to customize testing and training.

A hazard perception test for cycling children: an exploratory study

Traffic related cognitive skills have been tested for young car drivers with a Hazard Perception test but not for children, although they might benefit even more from it than young drives. Therefore An exploratory study to the use of a HP-test for testing the cognitive/traffic skills of young cyclists.

The efficacy of a brief hazard perception interventional program for child bicyclists to improve perceptive standards

INTRODUCTION Even though child bicyclists are highly vulnerable in traffic only few studies focused on providing child bicyclists with means to enhance their abilities to deal with the complexity of dynamic traffic situations. The current study therefore evaluated whether a brief hazard perception intervention might be effective to improve hazard perception skills in child bicyclists towards a level more comparable to adult bicyclists. METHODS Eighty children of the fourth grade (9.03 ± 0.43 years; 34 girls) and forty-six adults (34.67 ± 14.25 years age; 24 woman) first performed a Hazard Perception test for bicyclists. Response rate, reaction times, first fixation, duration of the first fixation, dwell time and total number of fixations on the events were measured. Next, the children took part in the HP intervention in which video clips of dangerous traffic situations were presented. The intervention comprised two classroom sessions of one hour (1/week). A post-test was performed one day after and the retention-test three weeks after the intervention. RESULTS Children responded to more covert hazards immediately after the intervention (p < 0.05), but did not improve their response rate for overt hazards. Reaction times for the covert hazards improved on the post-test (p < 0.001) compared to the pre-test but this effect was reduced on the retention test. There was no effect of the intervention for entry time of the first fixation but the duration of the first fixation increased for the covert hazards (p < 0.05). Children made fewer fixations on the event compared to adults (p < 0.001), except for the covert hazards on the retention-test. The training also increased the number of fixations for the overt hazards on the post-test (p < 0.001) and the retention-test (p < 0.001) but only increased on the retention test for the covert hazards (p < 0.001). CONCLUSION The results demonstrated that a brief intervention for training hazard perception skills in child bicyclists is able to improve childrens situation awareness and hazard perception for potential dangerous situations. The training, however, was too short to improve children to higher adult levels.

Expert – Non-expert differences in visual behaviour during alpine slalom skiing

The aim of this study was to investigate visual behaviour of expert and non-expert ski athletes during an alpine slalom. Fourteen non-experts and five expert slalom skiers completed an alpine slalom course in an indoor ski slope while wearing a head-mounted eye tracking device. Experts completed the slalom clearly faster than non-experts, but no significant difference was found in timing and position of the turn initiation. Although both groups already looked at future obstacles approximately 0,5s before passing the upcoming pole, the higher speed of experts implied that they shifted gaze spatially earlier in the bend than non-experts. Furthermore, experts focussed more on the second next pole while non-expert slalom skiers looked more to the snow surface immediately in front of their body. No difference was found in the fixation frequency, average fixation duration, and quiet eye duration between both groups. These results suggest that experts focus on the timing of their actions while non-experts still need to pay attention to the execution of these actions. These results also might suggest that ski trainers should instruct non-experts and experts to focus on the next pole and, shift their gaze to the second next pole shortly before reaching it. Based on the current study it seems unadvisable to instruct slalom skiers to look several poles ahead during the actual slalom. However, future research should test if these results still hold on a real outdoor slope, including multiple vertical gates.