نشریه رفتار حرکتی
پیاپی 40 (تابستان 1399)

Physical and cognitive activities have positive effects on cognitive functions, but have been rarely applied in combination with each other. Therefore, the aim of present study was to investigate the effect of physical activity with different levels of cognitive load on the cingulate cortex's brain waves. The present study is semi-experimental. 30 sedentary female students with an average age 22.63 ± 1.92 years were selected by convenience sampling and equally divided into three groups (physical activity without cognitive load, physical activity with cognitive load and control). The experimental groups practiced specific training program for 16 sessions, but the control group performed their daily activities. Brain waves, before and after the training program, was recorded using EEG device in resting position and with open eyes. Fz, Cz and Pz data in the Delta, Theta, Alpha and Beta brain waves were analyzed using MANCOVA and Bonferroni post-hoc test in the significant level of 0.05. The results showed a significant decrease for Delta brain wave in Fz and a significant increase for Alpha brain wave in Pz among participants into both experimental groups. On the other hand, there was no significant difference between the effects of physical activity with and without cognitive load on the cingulate cortex's brain waves. According to the findings of the present study, physical activity with and without cognitive load could possibly provide the conditions for stimulation of neurons in the cingulate cortex, which may lead to adaptation in the nervous system.

The use of mental effort in variable practice and errorless training is different, as the reason for the increase in learning skills increase the error in the variable practice, while the optimal result of the practice in the errorless practice is due to the reduction of mental effort in it. The aim of this study was investigating the effect of cognitive effort in variability of practice and implicit learning using both of these learning methods on a complex task and under equal conditions of a cognitive secondary task. For this reason, 72 students were divided to six groups with 12 persons per each group of errorless-variable, errorful-variable, errorless-constant, errorful-constant, control-constant, control-variable. All groups in pre-test, three practice days, acquisition, retention and secondary transfer tests. Participants of errorful-variable group practiced in distances of 3.5, 3.25, 3, 2.75, 2.5 meters respectively, errorless-variable group practiced in the same and conversely distances, while errorless-constant, errorful-constant and control-constant only practiced in 2.5, 3.5 and 3 meters, respectively and control-variable practiced randomly all the distances. For analyzing of throwing accuracy, mixed Variance analysis (3*3) (group*day) in acquisition stage and (3*4) (group*test) in test stage were used with significant level of 0.05. In retention test, there were significant differences between errorless-variable and errorful-variable (P=0.001), errorful-constant (P=0.002) and control-constant (P=0.006). In transfer test, there were significant differences between errorless-variable and errorful-variable (P=0.001), errorful-constant (P=0.0001) and control-constant (P=0.002). Finally, it was concluded that errorless and control-variable practice methods can be suggested to trainers, Therapist for teaching of motor skills.

The purpose of this study was to investigate quiet eye duration and accuracy of performance of skilled and less skilled basketball players in successful and unsuccessful jump shots in the star-drill. Participants were skilled and less-skilled basketball players aged 20-29 years old. In order to record and analyze the data was used from the SMI Eye Tracker, I view ETG 2.7 and be gaze 3.7 software, the motion analysis system with six infrared cameras and Cortex software, as well as the accuracy of the performance of the groups was evaluated through 8 value check list. T-test and mixed ANOVA (two way) was used to statistical analysis and. The level of significant was set at 0.05. The result show that skilled players had better accuracy in jump shots than less skilled players. They had longer quite eye duration than less skilled players and also players showed that longer quiet eye duration in hit than miss. Therefore, it can be concluded that the effect of quite eye duration and its effect on the performance is not limited to task and situation.

Designed motoring programs for hyperactivity-induced children can lead to visible improvement in their behavioral problems. Therefore, this study aimed to compare the effect of perceptual-motor exercises and resistance-balance exercises on behavioral disorders in children with attention deficit hyperactivity disorder. In the current research, a semi-experimental design with two groups design with control group was used. A total of 36 boy children aged 12 to 5 years (18 preschoolers and 18 primary school children) with attention deficit hyperactivity disorder who visited the Zehnara rehabilitation clinic in Tehran, randomly assigned to two experimental groups (perceptual-motor exercises) and (resistance-balance exercises) and control group. For data screening and collection, Conners Parents Rating Questionnaire and Child Behavior Checklist (CBCL) were used and the results were analyzed using covariance analysis and Ben-fronni post hoc test. The results showed that the effect of perceptual-motor and resistance-balance exercises on reducing behavioral disorders in children with attention deficit hyperactivity disorder was significant (P <0.001).However, the results of Ben-fronni post hoc test showed that there was no significant difference between two experimental groups in reducing behavioral disorders (P <0.005). According to research results it can be said that motor activity with emphasis on perceptual-motor and resistance-balance exercises can reduce the behavioral disorders of children with attention deficit hyperactivity disorder and use of these programs in the treatment of these children is suggested.

Different studies have shown the advantage of the external focus of attention using relatively simple variables. The aim of this study was to investigate the constrained action hypothesis by underlying neurophysiological mechanisms tests of the lower extremity muscle in vertical jump under the impression of Focus of Attention Types. For this purpose, 12 male professional volleyball players (mean age: 24±1.92, mean weight: 73.5±8.7) performed a vertical jump on the force plate under two conditions in a counterbalanced order: external focus and internal focus. EMG activity of the lower extremity muscle was measured during jumps by using EMG device that coupled with force plate. Paired t-test results showed height of jump under the external focus was greater than that of the internal focus, while there were no significant differences in onset and offset times of the muscles activity between attentional focus conditions (onset times:(P=0.085), offset times:(P=0.08)). Also, the results show significant increases in EMG of the lower extremity with internal focus during concentric phase (P=0.005). However, there was no significant difference in EMG of these muscles between the internal and external focus in the eccentric phase (P=0.069). These results suggest that the intermuscular of coordination are not affected by the focus conditions but the intermuscular coordination is enhanced by the external focus of attention and the external focus of attention increase develop more automation of motor control.

The growth of all aspects of the child's existential origins arises. Environmental affordances are considered as a provocative factor to exploit opportunities and promote developmental change. The purpose of this study was to investigate the effect of play in two space, natural outdoor and indoor space on the social and perceptual development of preschool children. For this purpose, semi-experimental research design with pretest–posttest design and two homogeneous groups was used by convenient method. Statistical sample of research were 30 pre-school children aged 4/5-6/5 that 15 of them at the Natural School (natural outdoor space) and 15 in kindergarten (indoor space) registered. To measure social development, the Vineland Social Maturity Scale and to assess perceptual development, the Beery-Buktenica Developmental Test of Visual-Motor Integration was used. Results of mixed ANOVA showed that activity in outdoor and indoor, had a positive and significant effect on the social and perceptual development of children, but playing in nature had a greater effect on the social and perceptual development of children than indoor space. So that 84% of changes in social age and 88% of changes in their visual-motor Integration were due to outdoor activities. Therefore, the natural environment has a greater improvement in the social and perceptual development of children.

The present study aimed to investigate the validity and reliability of the Persian version of the mental training questionnaire in sport. The research method is applied and development tools which the method of data collection was field research. For this purpose, 242 athletes of various sports have completed the questionnaire of Behnke et al (2017). Confirmatory factor analysis based on structural equation modeling was used to determine the structural validity, and the internal consistency and concurrent reliability of the questionnaire were assessed using Cronbach's alpha coefficient. The results showed that the three-factor structure of mental skills (fundamental, performance and interpersonal skills) and the two-factor structure of mental techniques (mental imagery and self-talk) have a good fit. Cronbach's alpha coefficient was more than 0.7 for the whole questionnaire and five components, which shows the internal consistency of the questionnaire. Thus, can be used from mental training questionnaire in sport for evaluating mental training in Iranian athletes.

The aim of this study was to investigate Motor coordination of lower extremity in instep soccer kick. The participant of this study were 24 elite soccer players of professional Iran league which weren't have any injury in last 6 months. Twelve healthy subject (age 25.87±1.2years, height180.7± 4.6cm, and weight 77.25 ± 5.1 kg) and twelve ones (age25.25± 1.39 years, height181.37 ±5.0cm, weight 76.12±8.02kg) were the players who at least 2 years passed of their ACL reconstruction surgery. After 10 minutes of warm-up and performing five instep kicks, fifteen 14 mm spherical reflective marker were installed on specific anatomical points in the lower extremities; Then subjects performed instep kicks for three times. For performing each kicks subject keep out 3 steps from ball, then approach to the ball with 30° angle and kicks the specific goal are with dimension of 1.5mₓ1.5m, 5m distance to the ball and 0.5-meter distance from the ground. The kicks were records by motion analysis system with five digital cameras (Viconvcam 460) with a frequency of 200 Hz. Angels and ranges of motion of the hip, knee, ankle, foot& also thigh and shank angular velocity were calculated by using of Vicon work Station and Excel-2007 in the setting of MATLAB software. Data analysis were done in SPSS-18 software and by using of MANOVA test at significance level of 0.05.Significant difference results indicated in hyper extension angle of the hip, knee and ankle angle (P<0.05)but there was no significant difference in range of motion of the hip and thigh angle before ball impact (P>0.05). and also, there was no significant difference between the angular velocity of the hip of two groups (P=0.63). However, significant difference were found in the angular velocity of the shank in both groups (P=0.00). According to these results it can be concluded that reconstructed ACL surgary would change the mechanism of control& motor program of instep soccer kick and would have the most effective in the ankle & knee angle and have the lowest impact on the movement of the hip. Therefore, it is recommended that coaches& those who involved in sports teams should pay attention to these results.