Pieter Vansteenkiste

Cycling around a Curve: The Effect of Cycling Speed on Steering and Gaze Behavior

Although it is generally accepted that visual information guides steering, it is still unclear whether a curvature matching strategy or a ‘look where you are going’ strategy is used while steering through a curved road. The current experiment investigated to what extent the existing models for curve driving also apply to cycling around a curve, and tested the influence of cycling speed on steering and gaze behavior. Twenty-five participants were asked to cycle through a semicircular lane three consecutive times at three different speeds while staying in the center of the lane. The observed steering behavior suggests that an anticipatory steering strategy was used at curve entrance and a compensatory strategy was used to steer through the actual bend of the curve. A shift of gaze from the center to the inside edge of the lane indicates that at low cycling speed, the ‘look where you are going’ strategy was preferred, while at higher cycling speeds participants seemed to prefer the curvature matching strategy. Authors suggest that visual information from both steering strategies contributes to the steering system and can be used in a flexible way. Based on a familiarization effect, it can be assumed that steering is not only guided by vision but that a short-term learning component should also be taken into account.

Measuring dwell time percentage from head-mounted eye-tracking data - comparison of a frame-by-frame and a fixation-by-fixation analysis

Although analysing software for eye-tracking data has significantly improved in the past decades, the analysis of gaze behaviour recorded with head-mounted devices is still challenging and time-consuming. Therefore, new methods have to be tested to reduce the analysis workload while maintaining accuracy and reliability. In this article, dwell time percentages to six areas of interest (AOIs), of six participants cycling on four different roads, were analysed both frame-by-frame and in a ‘fixation-by-fixation’ manner. The fixation-based method is similar to the classic frame-by-frame method but instead of assigning frames, fixations are assigned to one of the AOIs. Although some considerable differences were found between the two methods, a Pearson correlation of 0.930 points out a good validity of the fixation-by-fixation method. For the analysis of gaze behaviour over an extended period of time, the fixation-based approach is a valuable and time-saving alternative for the classic frame-by-frame analysis. Practitioner Summary: A fixation-by-fixation analysis is compared with a frame-by-frame method to analyse dwell time percentage. Although some considerable differences were found between the two methods, a high correlation indicates that the results are very similar. Therefore the fixation-by-fixation method could be a valuable and time-saving alternative for the frame-by-frame analysis.

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.

Dealing with head-mounted eye-tracking data: comparison of a frame-by-frame and a fixation-based analysis

Although analysing software for eye-tracking data has improved a lot during the last decennia, analysis of gaze behaviour recorded using a head-mounted device is still challenging. In this paper gaze behaviour of six participants, cycling on four different roads, was analysed both Frame-by-Frame and on a fixation-based way. A Pearson correlation of 0.930 was found between the two methods, which points out good validity of the fixation-based analysing method. For the analysis of gaze behaviour over an extended period of time, the fixation-based approach can save a lot of processing time.

Visual guidance during bicycle steering through narrow lanes: A study in children

Recently, Vansteenkiste et al. (2013) explored how visual behaviour guides bicycle steering when cycling at different speeds through 15m long lanes of 10, 25 and 40cm wide. Participants were found to shift their gaze direction towards the end of the lanes at higher speeds, towards the near pathway on narrow lanes and more towards irrelevant areas on wider lanes. To investigate to what extent young learner bicyclists adapt their visual behaviour in a similar way as adults, the experiment was repeated with seven eight-year-old children, and results were compared to the adult data. Children were found to cycle slower through narrow lanes than adults. However, with increasing lane width and cycling speed, children made the same shifts of visual gaze direction as the adults. These results suggest that for a simple precision steering task, children are able to adopt a similar visual-motor strategy as adults, provided that they cycle at their own pace.

Recognizing induced emotions of happiness and sadness from dance movement.

Recent research revealed that emotional content can be successfully decoded from human dance movement. Most previous studies made use of videos of actors or dancers portraying emotions through choreography. The current study applies emotion induction techniques and free movement in order to examine the recognition of emotional content from dance. Observers (N = 30) watched a set of silent videos showing depersonalized avatars of dancers moving to an emotionally neutral musical stimulus after emotions of either sadness or happiness had been induced. Each of the video clips consisted of two dance performances which were presented side-by-side and were played simultaneously; one of a dancer in the happy condition and one of the same individual in the sad condition. After every film clip, the observers were asked to make forced-choices concerning the emotional state of the dancer. Results revealed that observers were able to identify the emotional state of the dancers with a high degree of accuracy. Moreover, emotions were more often recognized for female dancers than for their male counterparts. In addition, the results of eye tracking measurements unveiled that observers primarily focus on movements of the chest when decoding emotional information from dance movement. The findings of our study show that not merely portrayed emotions, but also induced emotions can be successfully recognized from free dance movement.

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.

A coaches’ perspective on the contribution of anthropometry, physical performance, and motor coordination in racquet sports

ABSTRACT Differences and similarities between table tennis and other racquet sports exist, but are not well documented in the literature, in spite of the relevance for talent identification. In this study we aimed at identifying the key characteristics of table tennis in comparison with tennis and badminton based upon a survey in coaches. A total of 177 licensed coaches from all across the world and with diverse professional backgrounds completed a survey on anthropometric measures, physical performance, and motor coordination skills. On a scale from 1 to 10, coaches indicated to what extent a talent characteristic was important for their sport. MANOVA identified key differences as well as similarities between all three racquet sports and a subsequent discriminant analysis allocated coaches correctly for table tennis, tennis, and badminton 81.01%, 55.6%, and 71.4% respectively. Our results show that table tennis and other racquet sport coaches are well aware of differences between the racquet sports and also the importance and value of testing and assortment of skill components. These findings can assist coaches in future talent orientation and transfer in racquet sports.