In this investigation the authors presented an attentional demand explanation for the choking under pressure occurred in sport skills. For this porpouse, attentional demands in tennis serve performance was compared under low and high pressure conditions by using dual task paradigm. Twenty tennis players served as participants and performed sixty serves as primary task in low and high (competition) conditions. Secondary task was to respond an auditory stimuli that presented during tennis serve in four probe positions. The results showed that on one hand, the pressure condition deteriorated tennis serves performance and on the other hand, it caused an increment in level of attentional resources and changeed pattern of attentinal demands. The results indicated that skillful athletes allocated more attention to their performance and more focusing to some positions of the skill under pressure condition compared to normal condition. It suggested that such attention demands changes can cause choking in sport. The results provide objective and stronge support for the predictions of self-focus theories proposed for choking in sports.

The aim of the present study was to determine the relationship between perfectionism and competitive anxiety in Women's national karate team. Methodology: This is descriptive and correlational study in which 30 women from national karate team (adults and younger adults) formed the whole statistical population Completed the Martens Competitive state and competitive trait anxiety questionnaire and also completed the Dunn and colleagues’Sports perfectionism questionnaire. The findings of the research were analyzed using descriptive statistics (mean & standard deviation), Pearson correlation coefficient and Stepwise regression analyses. Results: Results from Pearson correlation coefficient indicated negative correlation between perfectionism sport and self-confidence, and a positive correlation with trait anxiety. Stepwise regression analysis results indicated that perfectionism is generally the strongest predictor of trait anxiety. Also, perceived pressure from the coach predictor of cognitive anxiety and self-confidence, and concern over mistakes and personal standards are predictors of somatic anxiety. Conclusions: moderating Perfectionism helps the athlete to be less affected by competitive anxiety, increases her self-confidence and thus, the probability of success increases.