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Introduction: Training in a certain skill not only culminates in better motor performance but also leads to neural adjustments and regulations in different brain regions. Aim: The present study aimed to psychologically assess event-related motor potential in motor-related cortical regions during simple and complicated tasks. Method: The current research was of a semi-experimental type with a single-phase post-test design without a control group. The participants of the present study consisted of all 20-32-year-old right-handed male table tennis players in Tehran, in 2019. A total of 8 samples were selected via convenience sampling. Data were collected at the National Brain Mapping Laboratory. Annett Hand Preference Questionnaire (1970), Ocular Dominance Testing Card (1910), the Newgy Robo Pong Model 2050 Digital Table Tennis Robot, and the Specific Test for Table Tennis Stroke (2016) were used to record speed from Radar gun, and cameras and judges’ scoring were also used to measure accuracy. Moreover, the two-way analysis of variance (ANOVA) statistical test was employed to assess the differences in two levels of task complexity in SPSS software version 24. Results: The results showed that the motor potential in the primary motor cortex region had a greater range in the simple task than in the complicated task (P=0.012); however, the premotor (P=0.008) and the posterior parietal cortical regions (P=0.026) of the complicated task had larger ranges than the simple task. Conclusion: According to the results of this study, the motor potential range is dependent on the task complexity level. Therefore, it is suggested that tasks with different complexity levels be taken into account in investigating event-dependent potentials.

This study aimed to investigate ego-depletion, attention control, and decision-making in proficient female soccer players. Utilizing a quasi-experimental design with an applied objective, the research was conducted intra-group using a pre-test-post-test methodology. The statistical population comprised proficient female footballers who competed in the Premier League of Tehran Province. This study involved forty proficient female football players, with an average age of 23.09+2.03 years, who had at least eight years of competition experience. The samples were arbitrarily divided into two groups—ego-depletion and non-ego-depletion—using convenience sampling. The data were collected using the personal information questionnaire, General Health Questionnaire, Stroop, and the Decision-making tool. The ego-depletion group’s self-control strength was diminished in two cycles of eighty trials through the prior task, which was the Stroop inconsistent task. They executed a computer-based decision-making task under distracting conditions, which comprised 180 images depicting various football scenarios. The data analysis was conducted using SPSS-21 software and a mixed ANOVA with the SYNTAX command. The results showed that the ego-depletion group made decisions with significantly slower speeds and reduced accuracy (P

Background: In previous studies, the effect of arousal on performance has been investigated. However, whether arousal during learning stages affects bimanual coordination has not been investigated. Therefore, the present research aimed to investigate the effect of arousal levels during different learning stages on the performance of the hand-eye coordination task.Methods: For this purpose, 36 male physical education students aged 20-35 were conveniently selected and based on normal IQ, normal trait anxiety, and right-handedness, were matched into three Low Arousal, Normal Arousal, and High Arousal groups. The study involved pre-test, post-test, retention, and transfer stages. In the pre-test stage, the participants performed 10 trials of the eye-hand coordination task. The training period consisted of 10 sessions and 50 trials per session, in which at the end of each session 10 trials were recorded as performance. The retention and transfer tests were performed 24 hours after the last training session. The data were analyzed using repeated measure analysis of variance, one-way analysis of variance, and Tukey's post hoc tests.Results: The results of the present study showed that high, normal, and low arousal levels have a significant effect on the duration of the eye-hand coordination task during the cognitive, association, and automatic stages, and also the time of the eye-hand coordination task was improved.Conclusion: According to the results of the study, it is suggested that educators use these arousal stimulation effects to improve the performance and learning of athletes in pursuit tasks.

Introduction: Primary stress can impair the nervous structure including the hippocampus and behavioral functions such as memory; therefore, paying attention to neutralizing the destructive effects of stress on the body has been one of the debatable topics among researchers. Considering the role of physical activity in reducing stress in previous studies, this study aimed to investigate the effect of four weeks of swimming training on learning and spatial memory in neonatal rats separated from their mother. Material & Methods: In this study, 40 male albino Wistar rats were randomly divided into four groups (separation from mother, separation from mother and swimming training, swimming training, and control). The method of separating the infants from the mothers was used to make stressful conditions. Rats from separation groups were separated from mothers 6 h per day starting from the day after birth for one month. For physical activity, swimming training was performed for four weeks (five sessions per week) incrementally to measure stress and blood glucose level in mice, and the Morris Water Maze test was used to assess the learning and spatial memory. (Ethic code: IR.UT.SPORT.REC.1399.009) Findings: The results of the analysis of variance test showed that the blood glucose in the group of rats that were separated from their mothers was significantly higher, compared to the control group (P=0.045), indicating that stress was successfully induced in these rats. Moreover, the results of the multivariate analysis of the variance test showed that although stress had no significant impact on spatial learning, the results of the exploration test showed a significant decrease in the percentage of entering the target quadrant (P=0.05) and the time spent in the target quadrant in the group separated from mother (P=0.029), compared to the control group. Therefore, spatial memory was degraded due to stress in the group of rats that were separated from their mother, compared to the other groups. However, swimming training in the group of rats that was separated from the mother could neutralize the destructive effects of stress on spatial memory and the percentage of entering the target quadrant (P=0.02) as well as the time spent in the target quadrant (P=0.05). Discussion & Conclusion: The results showed that although stress did not have a negative impact on spatial learning, it had a destructive impact on memory. On the other hand, swimming training as a treatment method could largely neutralize the negative effects of stress and improve memory.

Behavioral studies in team sports are typically constrained by dynamic factors, such as positioning of defenders for interception. Handball player have to coordinate their steps when running to throw a ball on goal from a different positions. In this study were analyzed the movement patterns during locomotors pointing, throwing velocity and accuracy of 12 succesful elite handball players under defensive constraints (defender- absent, defender-far, defender-near, or defender pairing). It was captured data from the locomotors patterns of the attacking participant by speed camera with 120Hz, throwing speed by sports radar gun and throwing accuracy by camera. ANOVA with repeated measures and Bonferroni post hoc test and Friedman test was used to analyze effects of these constraints on gait and throwing parameters. In addition to Pearson and Spearman correlation coefficient test was used to analyze speed-accuracy trade off (P

Background: The Arousal is one of the psychological factors affecting athletes' performance. The most important theory of the relationship between arousal and performance is the inverted-U theory. Despite research in this area, more research is needed on the effects of arousal on cognitive and motor activities. Aims: The purpose of the present research is to investigate the effect of arousal caused by spectators on the process and outcome of decision mking and volleyball serve performance skill. Methods: The research method was quasi-experimental and the sampling method was also available randomly. The population of the study is the volleyball players of Iranian youth and student volleyball national team. A number of 29 players (Mean age=19.62 ± 2.243 years) participated in this research. At first, the players filled out the satisfaction form. At first participants performed decision making test.The decision making task of current study was performance of volleyball serve decision making under arousal conditions caused by spectators. Participants performed 25 decision making situations in baseline and spectators arousal conditions. The visual saccade and fixation data recorded by eye tracker system (Ergoneers Dikablis Eye Tracking System) simultaneously with decision making test performance. Data analyzed with paired-samples t-test. Then the participants performed the volleyball serve performance test (Brady volleyball skill test). The instrument used in the study was high frequency camera Sony cyber shot rx100 iv that used to record the players' performance for biomechanical analysis of serve performance. The tracker software was used to analyze the video performance of players' serve skills. The presence of spectators in the test environment was used to create arousal and also the measurement of athletes' heart rate was used to measure arousal. The subjects performed 10 services and their biomechanical factors included; distance to line, serve height, serve distance to line, landing distance to line and ball speed was recorded by camera. To ensure arousal, their heart rates were measured. Results: The results of the serve performance t-test showed that the arousal caused by the spectators has a significant effect on serve height (P=0.033). Also the result indicated that arousal caused by spectators affected the process and outcome of decision making. Conclusion: Although the decision-making speed of the players increased under the circumstances of the arousal, their decision-making accuracy decreased. Given this, coaches need to provide good training tips in training to improve the decisions made by players. In addition to physical exercise, mental training and decision-making should also be done.

Introduction: Children with Attention Deficit Hyperactivity Disorder, in addition to attention deficit hyperactivity disorder and alertness problems, show the the lowest level of social activity and they have more trouble finding and keeping friends. Aim: The aim of this study was to investigate the effect of motor and computer games on the attention and social communications of male students with attention deficit hyperactivity disorder aged 10-12 years. Method: The statistical population of the present study was all elementary male students aged 10-12 years with Attention Deficit / Hyperactivity Disorder in District 4 of Tehran in 2021 and 36 of them were purposefully and accessibly selected. Motor and computer games were performed in 8 weeks and in each session in 3 sessions of 60 minutes. The Connors questionnaire of the parents' version and the Zebov questionnaire were filled out by the parents in the pre-test and post-test. Repeated measure analysis and paired t-test were used to analyze the data using SPSS software version 23. Results: Motor and computer games had a significant positive effect on attention and social communication; also, motor and computer games have a significant positive effect on the perceptual-motor skills of male inactive students (P≤0.05), but there was no significant difference between the effects of these two interventions on any of the research variables (P≥0.05). Conclusion: Motor and computer games improve attention and social communications in children with attention deficit / hyperactivity disorder; therefore, it is recommended that these games be used to help children with attention deficit / hyperactivity disorder.

Nowadays, universities are known as the main context of thinkingNowadays, universities are known as the main context of thinking and contemplation and students have an essential role in the development of the society.Therefore,factors affecting educational and research performance are of great importance .The aim of the present study was to investigate the effect of PETTLEPimagery on bilateral transfer of handball skill.The Sample included B.Sc students in physical education at the University of Tehran,24 of which participated in this research voluntarily. After taking part in the pretest, the participants were randomly divided into2groups of imagery with dominant hand and non-dominant hand.Then PETTLEP imagery was applied on both groups for12 sessions.A posttest similar to the pretest was done after the last session.This was followed by aretention test after 24 hours and then a transfer test in the form of handball tripleshootafter30minutes.After ensuring the consistency of variances by Leven test and normality of the data by Shapiro-Wilk test,a multivariate analysis of variance(MANOVA)and an analysis of variance with repeated measures with a significant level of α=.05 were used.The results showed that intervention of PETTLEP imagery had a significant effect on skill transfer through the entire process(P≥.05).Thus,PETTLEP imagery causes the occurrence of bilateral transfer. Therefore, PEETLEP mental imagery is recommended to be used for the improvement of people's skill when employing bilateral transfer. Therefore, PEETLEP mental imagery is recommended to be used for the improvement of people's skill when employing bilateral transfer. Therefore, PEETLEP mental imagery is recommended to be used for the improvement of people's skill when employing bilateral transfer.

Background and Aim: Evaluating variability can help to investigate the process underlying motor coordination problems. The current study aimed to measure motor coordination and its variability in children with Developmental Coordination Disorder (DCD). Moreover, the symmetry of motor coordination variability in these children and the relation between motor skills and variability were explored. Materials and Methods: After evaluating motor skills in children, aged 7-10 years using Movement Assessment Battery for Children-2 (MABC-2), 15 children with DCD and 20 non-DCD children performed a bilateral coordination task. Using motion capture system, motor coordination and variability were recorded and calculated by computing continuous relative phase and its standard deviation, respectively. Ethical Considerations: The study with an ethical code of IR.UT.SPORT.REC.1396030 was approved by Ethics Committee of Faculty of Physical Education and Sport Sciences of University of Tehran. Findings: Children with DCD showed significantly higher variability, while there was no significant difference between the groups in performing the coordination task. Moreover, the variability of motor coordination was found asymmetrical in children with DCD. Finally, more variability was shown to be accompanied with lower score in motor skills of the participants. Conclusion: The current study shows the necessity of employing assessments related to underlying process of movement coordination such as variability, which can help to provide more comprehensive understanding of motor patterns of children with DCD and the strategies that they adopt to execute and produce movement.

This study aimed to investigate the effects of peripheral and central fatigues on depth perception error in students. The statistical population consisted of students in Khodabande city. 42 subjects (mean age of 16.88 ± 0.49 years) were selected by convenience sampling method. All subjects took depth perception pretest. Then, they were divided into the intervention and control groups. To produce peripheral fatigue (physical), the first group received physical fitness activity and the second group received mental activity to produce central (mental) fatigue. The third group did not perform any activity during the intervention period. The depth perception posttest was performed after the fatigue intervention. The results of one-way analysis of variance showed no significant differences in the pretest among the groups, but there was a significant difference in the posttest among the groups. LSD post hoc test results showed that central fatigue increased depth perception error in comparison with peripheral fatigue and no intervention (control group). But no significant differences were observed in depth perception error between peripheral fatigue and control groups. Paired t test results showed an increase in depth perception errors resulted from both types of fatigue and the lack of change in the control group. Overall, it can be concluded that central fatigue had an effective role in increasing students' depth perception error when compared to peripheral error. Therefore, coaches are advised to adopt appropriate conditions that reduce central fatigue.

Introduction: Physical activity increases serum levels of brain-derived neurotrophic factor (BDNF) in patients with Multiple Sclerosis (MS); however, the effect of learning a skill using mental imagery in the PETTLEP model and comparing its effectiveness with physical activity in the levels of this factor has not been investigated so far. This study aimed to compare the learning of a skill through PETTLEP imagery and physical training. Moreover, it was attempted to investigate the effect of the combination of these two methods on BDNF levels and memory function in MS patients. Materials & Methods: In total, 30 women with MS and a mean age of 37.5±3.02 years Expanded Disability Status Scale (EDSS)=0-2 were included in this study. Based on Kim Karad visual memory test scores, they were divided into three homogeneous groups of 10 subjects per group. The groups included PETTLEP imagery, physical activity, and combined physical training and PETTLEP imagery. Before the intervention, visual memory was assessed using the Kim Karad visual memory test, and BDNF serum concentration by blood sampling method. The groups were subjected to three 30-min sessions weekly (for six weeks). After the intervention, the research variables were reevaluated at the posttest stage. Ethics code: IR.SSRC.REC.1397.012 Findings: The result of one-way ANOVA showed that the combination of PETTLEP imagery exercises and physical training, compared to physical training and imagery alone, increased BDNF levels (P=0.026 and P≤0.0005, respectively). However, imagery training improved memory performance in the short term and long-term memory, compared to physical training (P=0.009 and P=0.034) or combined exercise (P≥0.05). Discussions & Conclusions: Combination of physical training and imagery is effective in the rehabilitation of MS patients, and it can be used as a non-pharmacological method in this regard.

Introduction: Nowadays, exposure to electromagnetic waves has raised concerns for pregnant mothers about cognitive disorders that affect neonates. Therefore, the present study aimed to investigate the effects of electromagnetic waves and physical activity on learning, spatial memory, and levels of a brain-derived neurotrophic factor (BDNF) in the neonates of pregnant rats. Materials & Methods: Pregnant Wistar albino female rats were randomly divided into three groups of seven animals per group (Physical activity [PA], Electromagnetic fields [EMF], and AP+EMF). All groups underwent intervention during 21 days of pregnancy period. Subsequently, 2.4 GHz frequency and swimming were selected for the intervention. After delivery, 21 neonates were kept under natural in vitro conditions for 56 days (until maturity). Eventually, the Morris Water Maze test was performed, and the hippocampus was removed to measure BDNF. Ethics code: IR.SSRI.REC.1399.919 Findings: The result of one-way ANOVA showed that the traveled distance (P=0.007) and time to reach the platform (P=0.01) in the EMF group was significantly higher, compared to the PA group. Moreover, the results of one-way ANOVA and Tukeychr('39')s post hoc test showed a significant increase in the level of the hippocampal BDNF in the groups of PA and EMF+PA, compared to the EMF group (P=0.007 and P=0.02, respectively). Discussions & Conclusions: Electromagnetic waves during pregnancy have a devastating effect on the memory and learning of the offspring of rats. However, physical activities, including swimming, can mitigate the destructive effects of these waves during pregnancy.

Cognitive constrain of individual constrains which can be created with imagery and is a factor in many tasks affecting the performance has been investigated. Thus, the aim of the present study was to investigate the effect of PETTLEP imagery on the accuracy and speed basketball pass skill. 44 female students of Faculty of Physical Education, University of Tehran (mean age of 22.45±2.3 years) were selected by convenience sampling method and participated in this study. In pretest, participants performed 2 blocks of 10 trials of accuracy and speed basketball pass. Then, they were assigned to one of the four groups homogeneously: accuracy pass PETTLEP imagery, speed pass PETTLEP imagery, accuracy control, and speed control. Two groups of imagery listened to the imagery audio during 3 days for 8 minutes per day. Then, subjects participated in posttest, retention and transfer tests. For data analysis, mixed ANOVA was used. In case of significance, independent t test was used for intergroup comparisons and analysis of variance with repeated measures was used for within-group comparisons with significance level of α=0.05. The results of analysis of variance indicated no significant differences between imagery and control groups in pretest. However, there were significant differences in posttest, retention and transfer tests between imagery and control groups (P≤0.05). Also, PETTLEP imagery of accuracy and speed pass improved accuracy and speed pass performance from pretest to retention test; however, there was no such process in transfer test (P≥0.05).

Introduction: The importance of implicit learning and ways to achieve it in learning motor skills is increasing. However, little research has been carried out on children and the effects of analogy on children’s compressive performance are unclear. This study is performed aiming to compare analogy and verbal learning on accuracy and angular velocity of dart-throwing skills in children.Materials and Methods: This experimental study was performed using a semi-experimental design in 24 children with a mean age of 11.06 ± 2.2 years. The subjects were selected by the convenience sampling method and randomly divided into three groups: verbal training, analogy, and control. After the dart throw test (10 attempts), the participants underwent 8 rehearsal sessions (including 50 attempts per session). Retention and transfer tests were taken 3 weeks after the last session and 10 attempts were made on the variables of radial error and angular velocity. Data were analyzed using mixed-design analysis of variance (ANOVA) (3 × 4 in performance and 3 × 3 in angular velocity). α = 0.05 was considered as the significance level.Finding: The results showed that the verbal group had a significant decrease in radial error in the acquisition (P < 0.001), retention (P ≤ 0.003), and transfer (P ≤ 0.025). However, an increase in error was observed in the learning (P ≤ 0.001) and transfer stages (P < 0.001) in the control group, and in the transfer stage in the analogy group (P ≤ 0.038). Moreover, the verbal group had a significant increase in elbow angular velocity (P ≤ 0.005), while in other groups there was no significant difference between the test phases (P < 0.05).Result: It seems that verbal instruction increases the angular velocity, improves accuracy and performance compared to analogy, and is more effective in children’s performance.

Theoretically, skill presentation will change behavior through processes such as imitation and motor repetition. If we want learning to happen, we need a process called training. Training can be delivered by the instructor through verbal and non–verbal instructions to the learner. One type of non–verbal instruction is pattern representation in which learner can learn through observation. The purpose of this model is to use the pattern representation as a means of transmitting information. Thus, the aim of this study was to evaluate the effect of three training methods: immediate, interspersed and combined imitation on Juno kata form performance. Therefore, 45 girls (9-12 years old) in Tehran city voluntarily participated in this study and were divided into three groups (each group 15 subjects) based on the type of intervention. Groups of immediate, interspersed and combined imitation had special imitation training programs with specific repetitions. In order to quantify data, 10-point Kata scale was used. As the data distribution and variance homogeneity were obtained, the result of analysis of variance with repeated measures showed that all three observational methods helped to improve the performance and this progress remained stable in the retention and transfer tests (P≤0.05). Also, the results of multivariate analysis of variance showed the priority of immediate imitation group on interspersed (P=0.0005) and combined (P=0.0005) imitation groups. The combined imitation group gained better scores than interspersed group (P=0.0005) and this differences was stable in retention and transfer tests.

Introduction: The effect of central vision occlusion on two-hand coordination tasks is assessed in previous studies. However, the effect of peripheral vision on these tasks is not clearly identified; therefore, the purpose of this study was to investigate the effect of limitation of peripheral vision on two-hand coordination tasks. Material and Methods: Seven right-handed and right eye-dominant girl students with a mean age of 24.00 ± 3.46 years participated in this study. Subjects tested under four experimental conditions including peripheral vision limitation of the position of right hand, left hand, and both hands, and no peripheral limitations of hand position in the two-handed Vienna coordination task with four tries for each condition. The data were analyzed using 1 × 4 repeated measures ANOVA. Results: All three conditions of visual peripheral limitation showed less errors than the conditions without visual limitation (P < 0.05). However, no significant difference was observed between four experimental conditions in the variable of total time (P > 0.05). Conclusion: It seems that the visual peripheral limitation, as an environmental constraint, may increase the focus and attention of people in the two-hand coordination task.

The aim of this study was to investigate the emergence of special skill in basketball free throw at different skill levels based on Newell's model of learning stages. Participants were assigned to three skill groups (n=10): coordination group, coordination control group, and optimization group. They threw 350 fixed shots from 7 parametric points (2.74, 3.35, 3.96, 4.57, 5.18, 5.79, 6.4), carrying out 50 shots in each point. Regression analysis showed that the accuracy of those who were in the third stage of Newell's model in 4.57 m point, which is the same line of penalty, was significantly higher than the anticipated regression equation and supported the emergence of special skill (P>0.05), but the rest of the points did not follow the principles of force variability and performance accuracy decreased by increasing distance parameter. Moreover, multiple regression analysis showed that the rest of the points had no contribution to the emergence of special skill and this conclusion may be the reason for rejecting generalized theory in the creation of special skill.

Introduction: Quiet eye had been introduced as a period of extended gaze fixation in many targeting tasks. The aim of this study was to investigate the effect of quiet eye training with self-control and constant-variable body organization on performance and learning badminton low backhand service in the student novice girls. Materials and Methods: In this quasi-experimental study, 19 girl students of physical education in University of Tehran, Iran, were selected using convenience sampling method and randomly divided into two groups of self-control (n = 9) and constant-variable (n = 10). The task intention was badminton backhand low service. In order to measure the accuracy of backhand low service, we used French short serve standard five test, and to record the visual data, Ergonear Eye Tracking test was used. The day after the pretest, participants took part in 3 sections of acquisition (8 blocks with 15 trails, a total of 360 trails), and 48 hours after the acquisition test, the test of retention and transfer was executed. The data were analyzed using Mixed ANOVA test of 2 × 4 at performance and 2 × 3 during the period of the quiet eye at a significance level of P ≥ 0.050. Results: Quiet eye duration showed a significant increase in both groups from pretest to retention (P ≥ 0.001). Therefore, it can be noted that both methods of practice had a positive effect on the quiet eye duration. However, in the accuracy performance, there was no significant different between the groups (P = 0.374) and within the groups (P = 0.890). Conclusion: It seems that the organization of constant-variable and self-control exercises has similar effects on the accuracy and quiet eye duration.

Background: Various theoretical approaches have different views regarding the role and importance of vision information in the production and control of movements, but how vision control mechanisms act under anxious conditions? Aims: The present research aimed to evaluate vision control mechanisms under anxious conditions in novice golf players. Method: In this quasi-experimental study, 20 novice golf players were selected through convenience sampling in the city of Isfahan. The task of the current study was the performance of golf-putting skill under different anxious conditions (baseline vs. anxiety). In this study, participants in the baseline and anxious conditions performed 6 trials of counterbalance in each condition without blocking (control), the first phase blocking, and the last phase blocking of movement in each task. Simultaneously with golf-putting performance, the quiet eye data were recorded by an eye tracker system. Data were analyzed via two-way ANOVA and Tukey’s post hoc statistical methods. Results: The results indicated that participants’ quiet eye significantly decreased under anxiety conditions (p=0/0001). Also, the results showed that the initial blockage of movement caused further weakening of the accuracy and quiet eye compared to the final blockage of movement (p=0/0001). Conclusions: Overall, the results of the current study emphasize the pre-programming system in the performance of golf-putting skill in novice golf players.

Coordination is an important part of successful movements in daily life and sports. The aim of this study was to investigate the effect of different levels of cognitive activities on intrapersonal and interpersonal motor coordination in taekwondo athletes (Poomsae). The population consisted of Poomsae male athletes in Tehran city. 30 individual Poomsae athletes and 30 team Poomsae athletes (age range: 17 - 30 years old) were selected by convenience sampling method. The sample was divided into 3 groups: control, easy cognitive activities and difficult cognitive activities. The control group only performed the motor coordination task whereas the cognitive groups performed the dual task. The results of one-way ANOVA test showed a significant difference for two handed (P=0.003) and two legged (P=0.04) coordination in total time factor (speed). Also, there was a significant difference in the error percentage factor for interpersonal motor coordination (P=0.02). In a two by two group analysis, the easy (P=0.003) and difficult (P=0.001) cognitive activities groups in two handed motor coordination and the difficult cognitive activities group in two legged (P=0.02) and interpersonal (P=0.01) motor coordination performed better than the control group. It is suggested that difficult activities should be used in addition to regular physical activities.

Introduction: The purpose of this study was to investigate the effect of attentional focus and frequency of feedback on performance and kinematics in basketball free throwing. Materials and Methods: In this semi-experimental research, fifty students were randomly selected using convenience sampling method, and were randomly divided in one control and 4 experimental groups (internal focus and 33% feedback, internal focus and 100% feedback, external focus and 33% feedback, and external focus and 100% feedback). Experimental groups conducted six blocks of ten attempts (every day two blocks of ten attempts) in one week, and in three sessions of training, and received internal or external focus feedback with the corresponding frequency (33% or 100%). After 72 hours, retention and transfer tests were performed with ten-attempt blocks. Performance (throwing accuracy) and kinematic data (joint angle and range of motion) were collected. Data were analyzed using ANOVA with repeated measures and one way ANOVA. Results: Feedback with external focus (100% and 33%) was more effective in improving throwing performance in retention and transfer tests (P < 0.050). Kinematic data analysis showed that external focus feedback groups had the least maximum flexion in the knee joint in retention test compare to acquisition stage (P < 0.050). Moreover, external focus groups had the least maximum flexion at the knee in retention test compared to internal focus groups (P < 0.050). In range of motion of the knee, external focus groups had more range of motion in retention and transfer tests compared to internal focus groups (P < 0.050). Conclusion: Performance improvement in external focus groups may be limited to certain changes in kinematic data, and in line with constrained-action hypothesis.

Introduction: Knee osteoarthritis is one of the most common musculoskeletal problems in older women which affects their daily life. It causes balance impairment, and increases the rate of falling in these patients. Therefore, the aim of this study was to compare the effects between tai chi exercise and glucosamine supplementation on the balance of older women with knee osteoarthritis. Materials and Methods: This was a clinical trial study, in which 75 women with knee osteoarthritis (according to the Kellgren and Lawrence scale) were chosen, and randomly assigned into 3 groups of tai chi exercise (performed 3 times a week for 3 month), glucosamine supplementation (3 times a week), and control (no intervention). Before and after interventions, static balance (measured by stabilometer in both open and closed eye) and dynamic balance [measured by timed up and go (TUG) test] were examined. Paired sample t and ANOVA tests were implemented for data analyzing at a significant level of less than 0.050. Results: Tai chi exercise had a significant effect on static [open (t = 9.57, P = 0.001) and closed (t = 5.30, P = 0.001) eye] and dynamic balance (t = 8.54, P = 0.001); supplementation variable had a significant effect only on dynamic balance (t = 2.21, P = 0.040); in control group, there was not any significant difference between before and after intervention. Comparing three groups, the ANOVA test showed a significant difference between the exercise and control group in static [open (P = 0.001) and closed (P = 0.001) eye] and dynamic balance (P = 0.040). Conclusion: It seems that tai chi exercises enhance the balance in older women with knee osteoarthritis. It also could be concluded from the results that only the exercise variable has the significant effect on subject’s balance compared to glucosamine supplementation.

The aim of this study was to investigate the effect of music types on depth perception during fatigue. Statistical population consisted of female students of Faculty of Physical Education at University of Tehran. 45 subjects (mean age 23.3 ± 2.16 years) voluntarily participated in this study. Participants were divided into three groups: slow music, fast music and control. Initially, all subjects participated in the pretest of depth perception using depth perception apparatus. Then, they received a similar exercise until reaching the threshold of exhaustion. After reaching fatigue, their error of depth perception was reassessed. Then, participants were asked to listen to the music specific to each group for 3 minutes in order to assess the effect of music on their depth perception during fatigue. Their depth perception was immediately measured as the posttest. Analysis of variance with repeated measures and one-way analysis of variance were used to analyze the data. The results showed that fast music did not significantly change depth perception error (P=0.602), but slow music significantly reduced this error (P=0.006).

Introduction: Motor skill acquisition studies have shown that the performance of a motor task will be smoother after practice; however, the type of practice is very important. Thus, the aim of this study was to investigate the effect of practice with task-specific instability on performance and acquisition of a throwing skill. Materials and Methods: This quasi-experimental study was conducted on 16 semi-skilled subjects under 2 practice conditions, with and without availability of visual feedback. Each practice stage involved 3 blocks of 10 trials. The subjects’ throwing skill was evaluated in pretest and posttests, before and after the practicing stages. Two repeated measures ANOVA and paired t-test were used to examine the differences between subjects in practicing and test stages at a significance level of 0.05. Results: No significant difference were observed between practice blocks in the two stages of practice; however, there were significant differences between pretest and posttest with blocks in the second stage (P = 0.001). Moreover, no significant differences were observed between the posttests of the two practice stages. Conclusion: Task-specific instability with blocking of visual feedback not only induces the acquisition of complex motor skills, but also prepares the individual for confronting unstable conditions. It is suggested that coaches and therapists train athletics and patients for performing complex skills under unstable conditions to better prepare them for confronting these conditions.

Perceptual-motor skills play a vital role in many tasks of daily life and sports skills. The measurement of coincidence anticipation timing ability is a method to evaluate perceptual and perceptual-motor skills. Thus, the main aim of the present study was to investigate the role of different organism, task and environment constraints in coincidence anticipation timing accuracy. For this purpose, 30 female adolescents (17-15 years old), young (20-40 years old) and elderly (60-80 years old) participated in 4 tests of coincidence anticipation timing. The tests included a coincidence anticipation timing task with green (1), blue (2), red (3) color background and an additional environment constraint (4) and participants had to coincide with the arrival of the stimulus in the target point and press the corresponding key. For data analysis, mixed ANOVA (3*4), 4 one-way ANOVA and 3 ANOVA with repeated measures were used for each group with adjusted Bonferroni. Statistical analysis showed a significant difference in test 1, 3 and 4 (P≤0.0125). Also, all groups showed a significant reduction in performance when the background color changed from green to red and the addition of the secondary task (P≤0.017). In addition, results indicated that the elderly group had the weakest performance compared with the adolescent and young groups and the reason might be a weakness in perceptual-motor systems related to age increase. Finally, different coincidence anticipation training programs were recommended for athletes, elderly and patients with perceptual-motor system weakness.

The aim of the present study was to investigate the effect of contextual interference on balance of mentally retarded people. For this purpose, 40 educable and mentally retarded boys in Qazvin city (mean age 24.45 ± 3.120) were randomly divided into two groups: blocked and random practice. After the pretest, given their practice arrangement, subjects in each group performed their workout for 4 weeks (3 sessions per week) as the acquisition phase. Acquisition test was conducted in the last session, and then retention and transfer tests were performed after 48 hours. After Kolmogorov-Smirnov test verified normal data distribution and Leven test examined the homogeneity of variances, analysis of variance with repeated measures showed that the intervention was effective and the groups significantly improved (P=0.0005). The results of the independent t test (to compare two groups in static balance) showed that random practice group performed better in retention test (P=0.007) whereas no significant differences were observed between the groups in transfer test (P=0.061). In addition, dynamic balance results showed that random practice group performed better than the blocked practice group and it had a significant difference in retention and transfer tests (respectively P=0.001, P=0.002). So, mentally retarded people can use the beneficial effects of random practice.

the purpose of this research was the effect of visual concurrent feedback on balance ability in 7-13 years old girls. Hence, for this purpose, thirty-four girls student (ranging 7-12 years old) were participated in this study. The students were divided to three group randomly, control, closed eyes and mirror visual concurrent feedback groups, after stork balance test pre-test. Then, groups under interventions completed related trainings. In the present study used paired t-test for comparison of intra-group and one- way ANOVA for inter group (p≤0.05). The result of ANOVA showed that there was no significant difference between pre-test (p≥0/05). But, there was significant improvement in mirror group compared to control group (p=0.001) and closed eyes group (p=0.001). In addition to, the result of paired t-test indicated that only the mirror group has significant progress (p=0.007) in balance and the other groups have significant decrements. Therefore, concurrent feedback in children by use of a mirror to show them self can be improve their balance ability

The self-talk is one of psychological interventions that can be effective on improving and success in the motor performance and sport performance. So, the aim of the present study was to investigation effectiveness the motivational self-talkon secondary task performance (discrimination reaction time). 30 subjects have participated of the 160 students studying at the undergraduate from faculty of physical education and sport science in University of Tehran. They were divided randomly into two control and experimental groups. The intervention was conducted in two sessions per day and each session lasted one minute. The first primary task for the intervention group was walking on the treadmill with a slow speed whereas secondary task (discrimination reaction time), was performed in 10 attempts. The process was performed for the second order in the same manner with the difference that the experimental group performed motivational self-talk 15 seconds before the secondary task performance.Control group was performed test without intervention.The result of paired samples t-test showed that motivational self-talk in experimental group leads to a significant decrement in discrimination reaction time (P=0.001). Also, the result of Mann-Whitney U showed that reaction time in the experimental group decrease than control group significantly (P=0.002).

Increased level of stress has negative effects on cognitive functions. Thus, it is necessary to identify appropriate strategies to prevent cognitive and motor performance decline. The aim of this research was to study the effect of immobilization stress on learning and memory and the protective role of physical activity in them. From male Albino-Wistar rats of Pastor Institute, 32 rats were randomly divided into four groups. According to the type of the groups, rats were exposed to stress interventions including immobilization (two hours per day for 21 days), moderate running (30 minutes per day for 21 days), combination of stress interventions and running and also without any interventions. In order to determine the effectiveness of stress, animal weights were measured in two phases: before the protocol and after the tests. Morris Water Maze in several steps (four days for the acquisition phase, the fifth day for Probe test, three days for resting and the ninth day for recall test) was used for learning and testing of rats. ANOVA test with repeated measures and paired sample t test in acquisition phase and Tukey post hoc test were used to analyze data. The results revealed that stress damaged learning and memory (P=0.03). However, physical activity neutralized performance damage caused by stress (P=0.000). Physical activity group showed a significant positive effect on the time to reach the platform in the acquisition phase (P=0.005) and on cognitive function in recall phase (P=0.006) which was a sign of positive effect of physical activity on learning and memory. Therefore according to the present results which show that stress impairs learning and memory, it is expected that physical activity will be used as an effective factor to moderate stress.

The concept of imagery is to make an image of successful movement skill or a relaxing image in mind with no body training and external experience. The aim of the present study was to compare the effect of traditional and PETTLEP mental imagery methods on static and dynamic balance. The statistical population consisted of all female University of Tehran students who had general physical education course (1) in the first educational semester in 1389-1390. 54 participants (Mean age 21.94±1.89 yrs) attended voluntary in this study. First, they completed the Revised Movement Imagery Questionnaire (MIQ-R: Hall & Martin, 1997). Afterwards, pretest of static balance (Stork Balance Test) and dynamic balance (Modified Bass Test of Dynamic Balance) were performed. Participants were randomly assigned to three (n=18) groups (Physical training, Traditional imagery and PETTLEP imagery) and trained for 12 weeks (20 min/week). Finally, posttests of static and dynamic balance were performed under the same condition as the pretest. Retention test was performed 24 hours later and transfer test 30 minutes after the retention test. One-way ANOVA test showed no significant difference in static balance, dynamic balance and imagery ability scores in pretest among groups (p>0.05). Although ANOVA with repeated measures illustrated that although all three groups improved significantly in static and dynamic balance (P0.05). Overall, results showed PETTLEP imagery was an effective method but not sufficiently efficient in dynamic balance.

The purpose of this study was to evaluate the effect of dietary zinc levels during gestation on physical development of offspring. The statistical population consisted of adult male and female rats (Albino-Wistar) which were obtained from Pasteur Institute, Iran. After mating, 9 pregnant female rats were divided into 3 groups: 1) Zinc deficient group (0.05

The purpose of this study was to evaluate the effect of two regimes during rats' gestation and lactation on learning, memory and motor function of their offspring. For this purpose, female rats (Albino-Wistar) were obtained from Pasteur Institute, Iran. After mating, 12 pregnant rats were divided into three groups and they had their special regimes during their last week of pregnancy as well as their lactation. Control group used a standard diet, the zinc deficient (ZnD) group a diet deficient in zinc and the zinc supplement (ZnS) group a standard diet and enhanced zinc (10ppm) in their drinking water. 12 male offspring in each group were selected as the statistical sample and they were tested for learning and memory in MWM on their 56th natal day (ND) and were tested for motor activity in open-field on their 66th natal day. One-way ANOVA, post hoc Tukey test and repeated measures ANOVA were used to analyze the data (P

Postural control is one of the important abilities in daily life and sport activities of human beings and the importance of focus of attention is always discussed in this issue. In this regard, the aim of the present study was to investigate the effect of the instructions of focus of attention of supra-postural task on performance and learning of postural control in girls aged between 9 and 12. 45 female students in an elementary school in Malayer city participated in this study and were randomly divided into 3 groups: external attention, internal attention and control by drawing of lots. The participants were asked to maintain their postural control by instructions on supra-postural task. Instructions included focus of attention on the bar they held horizontally (external focus), on their hands (internal focus) and no instructions (control). The results of analysis of variance with repeated measures showed that learning process in external focus group was significant compared with the internal focus (P=0.049) and control (P=0.005) groups. However, no significant differences were found in learning between internal focus and control groups (P=0.345). It can be concluded that external attention instruction on supra-postural task led to better postural control than internal attention instruction.