Background and Purpose
Athletes continuously use visual information in the performance of sports skills, then this information is processed by the brain and they create the appropriate movement in the form of movement commands. Gaze behavior is necessary to collect accurate vision information and control human movements in sports and life. In the definitions, gaze behavior includes four components: fixation, saccade, tracking, and steady eye. In interceptive skills where the target is constantly moving, the athletes must first fixate on the object, then track it and process its direction, and finally organize their limbs to adapt to it. A variety of visual training can be used in the performance of interceptive tasks, including the quiet eye training proposed by Vickers. Research has confirmed the effectiveness of quiet eye training in children's fundamental skills and targeting and interceptive tasks in children. Considering the necessity of developing specialized skills, including volleyball, and the challenging nature of volleyball training for beginners, this study aims to investigate the effect of quiet eye training on the fixation of gaze in learning volleyball service.
 
Methods
20 beginner female students (mean age = 10.12) were selected as available samples. First, the participants warmed up with sports movements. Then, they were equipped with an eye-tracking device. A pre-test was taken, which included receiving 20 volleyball serves and sending them to the passer (10 simple and 10 smash serves) in three designated areas of the mini volleyball court (1, 3, 4). During the execution of the service, the gaze of the service receiver on the contact point of the server's hand with the ball was recorded by the eye-tracking device. Also was recorded the number of receptions that were done with the service receiver staring at the passer while receiving the ball. After taking the pre-test, they were randomly replaced into two groups of 10 people (technical and quiet eye training). The skill of receiving a volleyball serve was taught using the video of a skilled person's performance and the coach gave both groups verbal action instructions. Both groups participated in 9 training sessions individually (three sessions a week). In each session, each person performed 5 blocks of 10 receiving and sending volleyball services. The exercises of the technical group included receiving and sending service to the passer from different directions and distances, which were performed as variable exercises by changing the parameters of the distance and direction in different areas. Quiet eye group training was performed based on Vickers' 7 steps of QE training (8): 1- The first step, the gaze behavior information of the skilled sample was defined. 2- In the second step, the subject's gaze behavior was recorded by the eye tracker for 20 service receptions in the pre-test, to provide visual feedback and compare it with the skilled sample. 3- In the third step, the subjects were trained by using the performance video and the gaze behavior of a skilled person to receive volleyball service. 4- In the fourth step, the visual information in the action of the subjects was compared with the visual information in the action of a skilled person and the subjects were asked about the differences. 5- In the fifth step, the subjects were asked which of the features of the gaze behavior they wanted to improve. 6- In the sixth step, the task of receiving a volleyball serve was implemented in the form of variable exercise to lead to an increase in the length of fixation of the gaze. 7- In the seventh step, the service recipient's visual attention was evaluated competitively. 48 hours after the last training session, the first retention test and one month later the second retention test was performed. Data analysis was done with a composite analysis of variance and the Yeoman-Whitney test at a significant level of P ≤ 0.05.
 
Results
The results of the analysis of variance did not show a significant difference between the two groups in the length of the fixation of the receiver's gaze on the point of contact of the server's hand with the ball in the three test stages (p=0.065). The results of the Mann--Whitney U test did not show a significant difference between the two groups in the number of receptions of the service that was performed with the fixation of the receiver's gaze on the passor in the first (p=0.165) and second retention (p=0.052). It seems that quiet eye training has a significant effect on the learning of the interceptive task compared to technical training and a similar effect on the fixation of children's gaze.
 
Conclusion
According to this research, the performance of receiving volleyball service improved significantly in both groups from the pre-test to the first and second retention, which shows the effect of both quiet eye training and technical on learning movement skills. However, the performance of the quiet eye training group was better than the technique training, which shows the greater effect of quiet eye training on motor learning. However, no significant difference was observed in the gaze fixation in both the technical training and quiet eye training groups indicating simultaneous perceptual and cognitive adaptations during motor learning. On the other hand, the inhibition hypothesis explains the longer gaze fixation and the greater effectiveness of quiet eye training in skilled subjects but in the present study participants were beginners. It is concluded that quiet eye training increases the performance and learning of beginners compared to technical training but has the same effect on gaze behavior.
 
Article Message
This study highlights the potential of perceptual–cognitive training approaches, such as quiet eye exercises, in developing motor learning and attentional control in children's sport education.
 
Ethical Considerations
The ethical approval for this study was obtained from the Sport Sciences Research Institute under the code IR.SSRC.REC.1402.227.
Authors' Contributions
Conceptualization: Fatemeh Sharafiyan, Mehdi Shahbazi, Shahzad Tahmasebi Boroujeni
Data Collection: Fatemeh Sharafiyan
Data Analysis: Fatemeh Sharafiyan, Mehdi Shahbazi
Manuscript Writing: Fatemeh Sharafiyan
Review and Editing: Mehdi Shahbazi, Shahzad Tahmasebi Boroujeni
Project Manager: Mehdi Shahbazi
Conflict of Interest
The authors declare that there are no conflicts of interest concerning the publication of this manuscript.
 
Acknowledgments
The authors would like to sincerely thank all the participants in the study for their collaboration.