فهرست مطالب mohammad hosein ghahramani

The main aim of this study was to investigate the effect of different levels of impulsivity on learning of skills in open and closed environments. Participations were forty-eight male with 10 to 12 years old that signed in low impulsivity, med impulsivity, high impulsivity and control groups (combined group) in accordance to the distribution of impulsivity scores. Before and after basketball skills training program, Harrison’s basketball shooting test was used to evaluation of performance and learning of skills in open and closed environments during pre-test, post-test, retention and transfer test. The results showed a significantly differences between groups for attentional functions (p=0.0001). The results of post-test and retention showed advanced performance in open environment with the increased levels of impulsivity (p=0.003). While about closed environment, progressive performance was aligned with Low levels of impulsivity groups (F=0.001). But in the transfer tests, differences between the groups were not significant (F=0.09), that was performed under the competitive goal condition. It is possible that impulsivity has a facilitator and an attenuator role in learning of various sportive skills, perhaps in open and closed environments.

Impulsivity features of individuals affect their movement patterns when learning sports skills. Therefore, this study examined the effect of different levels of motor impulsivity on learning basketball basic skills. 3 groups of boys aged between 10 and 12 who were selected according to motor impulsivity levels participated in a basketball skills training course along with a control group (the subjects were randomly selected). To evaluate their performance,AAHPERD and Hann basketball pass tests were used in thepretest, posttest, retentionandtransfer phases. The results of covariance and analysis of variance in posttest (P=0.0001) andretention test (P=0.011) inAAHPERD basketball pass showed a significant advantagein this test along with increased motor impulsivity levels.However,better performance were along with decreased impulsivity levelsinHann pass task. The observed differences among the groups were not statistically significantin the transfer phase(P=0.112). It can be concluded that different levels of motor impulsivity is one of the main factors affecting sport skills learningwith regard to the speed-oriented and accuracy-oriented skills.

The aim of this study was to investigate impulsiveness features of soccer players in different positions according to the mastery orientation approach. For this purpose، 40 soccer players in Iran first division league with mean age of 28. 65±3. 9 years in different positions participated in this study. To measure impulsiveness features، Barratt Impulsiveness Scale (BIS-11) and Continuous Performance Test (CPT) were used. Multivariate analysis of variance results indicated that goalkeepers and defenders achieved higher scores in cognitive and motor variables of impulsiveness factors and in misdiagnosis of continuous performance test items than the middle players and offenders (F(9،82) =3. 126، P=0. 001، Wilks Lambda 0. 228، partial η2=0. 389). Based on these results، it can be stated that impulsiveness is one of the main explanatory factors of players'' tendency towards different soccer positions along with other relevant variables.

Coping style is one of the substantial factors influencing sport achievements in sport competitions. The main aim of the present study was to examine the effect of sport stress coping styles on sources of acute stress and salivary cortisol in wrestlers. With regard to the criteria and variables of this study، 30 out of 270 active national wrestlers participated according to the cut-off point of coping styles questionnaire in two approach and avoidant coping groups. The participants were asked to complete Sources of wrestling acute stress questionnaire and to collect the saliva to measure salivary cortisol levels. Multivariate analysis of variance results indicated that sources of acute stress were significantly higher in approach coping wrestlers than avoidant coping group (P=0. 001). Also، salivary cortisol level was significantly lower in avoidant coping group than the approach coping group (P=0. 012). According to the results، different stress coping styles influenced perceived stress of acute stress and salivary cortisol levels in wrestlers. The findings of this study can be used in instruction of different sport stress coping styles in wrestlers in order to reduce their mental pressure in the competitions.

The aim of this study was to investigate Sources of acute stress in elite and expert wrestlers. Volunteer participants were 210 wrestlers of elite (age: 24. 9±4. 6 years) and expert (age: 23. 6±4. 9 years) wrestlers. Participants were asked to complete the Sources of Acute Stress among wrestling Questionnaire (SASWQ). Multivariate analysis of variance results indicated that there was significant difference between athletes participating in performance، evaluation، contest، error، prospect، time pressure، injury and environment in the Sources of acute stress، expert wrestlers gets more points than the elite wrestlers. F8،209 =3. 289، P=0. 001، PartialȠ 2=0. 997)، (p≥0. 05). Results indicate that the expert wrestlers in comparison with elite wrestlers allocate a large proportion of energy for addressing with mental pressure that arises from Sources of acute stress. While for the elite wrestlers، those obtain psychology distance from Sources of acute stress، hereby increase probability of self-sport achievement.

This study aimed at exploring the main sources of acute stress in wrestlers regarding the structure and the assessment of reliability and validity of the sources of acute stress in wrestlers questionnaire (SASWQ). For this purpose, this questionnaire was distributed among a sample of 330 wrestlers (mean age 21.56+5.3) in Tehran who were selected by multistage random sampling method. Analysis of data with SPSS software showed that the Cronbach's alpha for all items of this questionnaire was 0.909 and alpha coefficient of the internal consistency for the first and second section was 0.870 and 0.831 respectively. Content validity of the questionnaire showed the equity of each of the 8 principle components of acute stress in wrestlers including skill performance, evaluation, contest, error, prospect, time pressure, injury and environment as 2.43 on average through exploratory factor analysis in the principle component analysis (PCA) with Varimax rotation. In confirmatory factor analysis with Lisrel software, GFI=0.96, AGFI=0.92 and CFI=0.93 were obtained. The findings showed that SASWQ had acceptable reliability and validity and could measure the mentioned variable in the mentioned statistical population.