The Neurophysiological Effect of Attentional Focus as a Function of Expertise in Postural Task

Background: Examining effects of attention on motor performance at the neurophysiological level, considering the skill level, seems there are still ambiguities. Objectives: The purpose of the present study was to examine the neurophysiological effect of Attentional Focus on in postural task as a function of skill level. The performance (postural sways) and muscular activity changes was recorded shift concurrently in two attentional conditions. Methods: 20 gymnasts (19-26 Years old) participated and assigned to groups of skilled (10 years’ experience) and novices (3-5 years history of training in Gymnastics). All participant of both groups performed ten trails of semi-dynamic balance (10 seconds) in tow conditions of internal and external focus in a counterbalanced order. Postural sways were measured using Biodex Stabilometer and Electromyography (EMG) signals of Tibalis Anterior and Soleus muscles recorded using ME6000 device. Data were data were analyzed using 2×2 mixed ANOVA. Results: Results showed higher performance (less postural sways) and reduced EMG under external focus condition for novices and lower EMG activity for experts. Conclusion: Research findings (enhanced performance and reduced EMG) support Constraint action hypothesis. Focus of attention can have profound effects on motor behavior and the underlying neurophysiologic factors regardless of skill level but in behavioral level of analyze it effects depended on expertise

The Effect of Different Levels of Mental Fatigue on the Performance of Throwing of Skilled Handball Players

Background: The speed and accuracy of performance are affected by various factors, including mental fatigue. The current study investigated the effect of two durations of 15 and 30 minutes of mental fatigue on the speed and accuracy of throwing performance in skilled men handball players.  Methods: The present study was semi-experimental with the participation of 45 skilled players (24.98 ± 3.66 years) who were randomly assigned to 15-minute, 30-minute mental fatigue, and the control group. Mental fatigue was induced by the Stroop task, and the accuracy of the throwing, Hit percent, and speed of performance were measured before and after the induction of mental fatigue. Data were analyzed using mixed analysis of variance with repeated measure.  Results: Throwing speed and accuracy, as well as the Hit percent, decreased in both groups after 15 and 30 minutes of mental fatigue (P<0.05).  In the two groups of 30 and 15 minutes of mental fatigue, no significant difference was observed in the decrement of throwing accuracy (P<0.05). Conclusion: The impact of mental fatigue goes beyond specialized technical performance in a sport, and any decline in performance due to mental fatigue is likely related to motivational issues. Also, mental fatigue causes attention to be diverted from target stimuli to stimuli that are irrelevant to task performance, leading to a reduced capacity to tight control over the primary task. To protect the accuracy of performance in tasks requiring speed, the mental activity of the athlete should be avoided before the performance