سعید قربانی

Mental fatigue is a factor that may influence performance of chess players. However, effects of mental fatigue on performance of chess players are rarely investigated. Therefore, the aim of this study was to explore the effects of exposure to a mental fatigue protocol on memory function (pattern recall performance) of expert chess players. Thirty expert chess players (55-65 years-old) were randomly assigned into mental fatigue and control groups. Participants in the mental fatigue group were asked to (re-)place observed ordinary and random chess positions on a blank chessboard before and after exposing to a 30-minutes’ mental fatigue protocol. The control group followed the same procedure but they read a text about history of chess instead of exposing to mental fatigue protocol. Two ordinary and two random chess positions were used to measure pattern recall performances in pre- and post-tests. Visual Analogue Scale was used to measure the subjective rating of mental fatigue and motivation for upcoming pattern recall task. Results showed that exposing to mental fatigue protocol increased the subjective rating of mental fatigue significantly in the mental fatigue group. Moreover, motivation was not different between the groups before performing pattern recall task in posttest. Also, results revealed that exposing to mental fatigue protocol impaired pattern recall performance of expert chess players. Finally, expert chess players performed significantly better in recalling ordinary positions than random positions. Findings of the study can add to the existing knowledge on effects of mental fatigue on a variety of sporting context and also provide support for Chunking Theory of Memory and Template Theory.

Previous studies have shown that autonomy support (AS) can foster a person’s motivation and facilitate motor learning. However, the effects of AS on observational motor learning are not well understood. The present study investigated this issue by manipulating to-be-observed-model. Forty-eight male students were assigned into autonomy, yoked, and no-demonstration control groups. Three male Baseball coaches acted as models A, B, and C. Model A was instructor of students of AU group and acted as a model with high social status for AU group. Models B and C were not familiar for all participants and acted as low social status models. Participants were asked to perform a Baseball-pitch into a target during pretest (10 trials), acquisition phase (5 blocks of 10 trials), and retention test (10 trials). Prior to each acquisition block, the participants of AU and YO groups observed a model three times. Participants of AU group were free to choose model A, B, or C for any single observation. Participants in YO group were matched with those in AU group. Movement outcome, movement form, self-efficacy (SE), perceived learning effect (PLE), and perceived model attractiveness (PMA) were measured as dependent variables. Results showed that AS, relative to yoked and control conditions, led to better movement outcome during acquisition and retention. Action observation enhanced movement form during acquisition and retention. AS increased SE, PLE, and PMA compared with yoked and control conditions. Results provide support for the OPTIMAL theory and indicate that AS facilitates observational motor learning.