1. The influence of visual strategies used by National Water Polo goalies on decision time and accuracy improvement through a video based perceptual training program
Véronique Richard, M.Sc., Jonathan Lasnier, Jean Fournier, Ph.D -
ABSTRACT
METHODS
RESULTS
CONCLUSIONS
In conclusion, the intervention resulted in a slight improvement in the accuracy of decision-making during training sessions only. However, the intervention did not enable the improvement of side accuracy in any goalie. With regard to reaction time, only athlete (A3) improved. Finally, for all the athletes, the intervention seems to have resulted in improved performance in game situations.
Although the results did not confirm all assumptions, some suggestions are to be considered to promote the development of future projects on the process of decision-making.
Visual strategies could partly explain the reaction time improvement in A3. Unlike athletes A1 and A2, who set several different points in a short period of time (a strategy that involves more scanning), A3 used fewer fixed points, and focused longer on them.
It is important to standardize the difficulty of training sessions before the video (Lorains, 2013). This would allow for a better evaluation of the progression of athletes throughout the procedure.
It would be interesting to question the athlete's perception of commitment in different sessions. For example, if an athlete never manages to "immerse themselves" completely in the video, the results can be interpreted more easily (Gorman & Farrow, 2009).
The ecological aspect of this project seems to have been beneficial in improving performance in game situations (Guadagnoli & Lee, 2004). More studies should therefore opt for this type of methodology.
For the athletes to fully benefit from the implicit approach, it would be important to involve more coaches so that they are also using this type of approach in their daily workouts (Gorman & Farrow, 2009). In this way, the advantages of using this approach could be more readily perceptible (Masters, 2008).
It has been shown that video-based perceptual training improves cognitive and perceptual skills resulting in decreased decision time and increased decision accuracy in both simulation and field settings. It has also been shown that visual strategies employed by athletes influence decision-making in similar field settings. Thus, the goal of the present study was to implement a 14-week video-based perceptual training program to help 3 Canadian national team water polo goalies improve their decision making time and accuracy while tracking their visual strategies. Results show a decrease of 0,23 seconds in reaction time for one athlete; visual strategies used by this athlete, characterized by longer fixation on few fixed points, could partly explain this improvement. Finally, decision-making accuracy improved by an average of 15% in real game situations. In addition to visual strategies, the current results highlight the need to consider a number of things for the implementation of a video-based perceptual training, such as video structure and perspective, athlete engagement and general coaching approach. This study will therefore help coaches and practitioners better understand how to lead an efficient video-based perceptual training program.
Participants
3 goalies from the National Women’s Water Polo Team
Training hours = 25 hours per week
M age = 21 years
M experience on the national team = 1 year
Procedures
Video construction
The goalies’ coach helped put together the videos. 14 video sessions were built, with either various offensive situations, offensive situations executed by a particular team or a specific situation performed by several different teams.
Pre-test and Post-test
20 video clips
Environment: Out of the water
Athlete was wearing an Eye Tracker
Instructions: Watch the video, when the screen goes blank, show with your arms the decision you make as quickly as possible.
Training
14 training sessions at a frequency of 2 per week
Session 1 and 14 = 30 video clips
Session 2-13 = 20 video clips
2 week break between sessions 9 and 10 (training camp)
Clip duration : between 4 and 18 seconds
Occlusion: 4 seconds
Environment: In the water in front of their goal facing TV
Instructions: Watch the video and when the screen goes blank, execute the stop (real action) as quickly as possible.
Data analysis
After the complete session, the videos were analyzed using the software Kinovea (Kinovea ). To calculate the reaction time, the video was paused and the number of images before the athlete initiated her movement was counted from the time of occlusion. Subsequently, the number of images was multiplied by 1/30 (number of frames per second) which made it possible to get the response time in seconds.
The accuracy of the decision was analyzed by the goalie coach of the national water polo team.
Decision accuracy
In general, no improvement in decision accuracy was observed following the intervention. The results actually show a decline in decision accuracy between the pre and post test (graph 1). However, the intervention helped improve decision accuracy slightly during training (graph 2).
Difficulty level
Following the interventions, we asked the coach to make a subjective evaluation of the difficulty of the different sessions in order to assess the influence of the degree of difficulty on athletes’ performance. The results confirm that it is important to consider the difficulty of the sessions, because it seems that this has an impact on the relevance of decision-making in athletes (Graph 3).
Side accuracy
Regarding the side accuracy, the intervention did not help goalies improve (graph 4).
Perspective
Despite the fact that discomfort was reported by athletes when movies had different perspectives (external) than their usual perspective (internal), the results show that it did not affect their ability to differentiate the proper side. Indeed, whether the video represented an internal or external perspective, the athletes still chose the correct side in their actions (graph 5).
Reaction time
For athlete A3, the training improved reaction time by seconds (graph 6). Moreover, the average reaction time of all the goalies improved by 0.08 seconds (graph 7).
Transfer
The results show an improvement in decision-making accuracy in real game situations among all goalies (Graph 8).
INTRODUCTION
Video based perceptual training
Video based perceptual training programs involve asking the athlete to watch a series of video clips showing different sporting situations. Then, when the moment of decision-making occurs, the image is hidden by a white screen (occlusion). It is at this point that the athlete must make a decision as quickly and accurately as possible and complete the appropriate gesture (Milazzo et al., in press).
Visual strategies
It is known that the longer the eye remains fixated on a given target, the more information is thought to be extracted from the display (Mann et al., 2007). On the other hand, saccades, defined as eye movements between successive fixations, are believed to suppress information processing (Duchowski, 2002). Therefore, given the typically dynamic context of sport, researchers have found that visual search strategies involving fewer fixations or longer durations lead to better decision making (Williams et al., 1993).
Hypothesis
Based on many studies that have shown the effectiveness of video-based perceptual training programs (Alsharji &Wade, 2015; Farrow & Abernethy, 2002; Hopwood et al., 2011; Milazzo & Fournier, 2015), it may be hypothesized that the present project will help water-polo goalies to improve reaction time and decision-making accuracy. It was also expected that the athletes who used fewer fixations or longer durations would improve more over the course of the study.
green = 5
Blue = 6
yellow = 7
Orange = 8
Red = 9
References
References will be provided on demand