Study On Cognitive Features And Neural Mechanisms Of Elite Sanda Athletes In The Course Of Perceptual Prediction

Sanda is an unarmed combat event.Thus, conversion of attack and defense changes extremely fast and frequently in the competitions with the fleeting combat opportunity. In order to grasp the initiative of the game, athletes often select the coping strategies, or start answering behavior beforehand by means of partial information or antecedent informationthat can predict the opponent's tactical intent before the start of the adversary's movements. Therefore, the prediction and judge in Sanda event are the important bases for accurate and rapid response of athletes. Studies have shown that elite athletes have good predictive power of perception, and this ability can be consolidated and improved by purposefultraining. However, due to the constraint of experimental conditions and methods of research and technology, people have not yet researched the cognitive neural mechanism of elite athletes in the process of perceptual prediction.This study found the following deficiencies of the current research through overviewing of relevant literature:First, most of the researches stated the use of cognitive information processing while weakened the research on the whole process of mental activityan and the existing researches show a lack of integrity. Second, behavior and eye-movement index are mostly used in the course of evaluation of perceptual prediction, while electrophysiological index are seldom mentioned, which can not reveal features of neural activity during the process of perceptual prediction. Third, differences exist between training effectiveness and training performance of perceptual prediction, which needs the research support of neuro-psychological leve, so that the inherent laws of perceptual prediction training can not be clearly clarified.Therefore, theoretically guided of postnatal experience of cognitive advantages for experts athletes, with the main line of athletes'information processing, the study will divide the process of perceptual prediction into visual search, motion-recognition, prediction, using expert-novice paradigm, together with the techonology of event-related potentials and eye movement recording techniques, to research the cognitive features and neural mechanism of each information processing of excellent Sanda athletes. Furthermore, the study will clarify the inherent laws of perceptual prediction during the process of information processing on the elite Sanda athletes. On this basis, the study tries to explore training performance issues of perceptual prediction on Sanda athletes, and provide theoretical guidance to the practical training.The results show:(1) Elite Sanda athletes, compared with beginners, have a faster speed of visual search in the general situation, a shorter latency of the evoked P1 from parietal area, a larger amplitude of the evoked N1 from parietal area and occipital area; The more the number of interference stimuli, the larger N1 amplitude induced from the corresponding region of subjects. (2) Compared with beginners, elite Sanda athletes have a faster visual search speed, higher accuracy in the special situation, a shorter latency of P2, N2, P3 induced from the corresponding brain and a smaller amplitude of P3, P2, a larger amplitude of N2; The more difficult the search is, the longer latency of P1, P2, N2, P3, and the larger the amplitude. (3) Compared with beginners, elite Sanda athletes have a higher efficiency to recignize skilled motion, and the a shorter latency of evoked N1, P3 from corresponding region, a larger amplitude of P1, N1; Compared with the picture material, subjects have a longer latency and a larger amplitude of P1, N1, P3 with video material identification (4) Compared with beginners, elite Sanda athletes have a higher efficiency of pre-judgment, and a shorter latency of induced P1, N1, P3 from the corresponding region, a smaller amplitude of P1, P3, a larger amplitude of N1. Compared with the picture material, subjects have a longer latency of P1, N1, P3, a larger amplitude of P1, P3, a smaller amplitude of N1 with pre-judgment of video material. (5) Perception training of special situation based on visual search and pre-judgment makes beginners to shorten the time of pre-judgment, improve the accuracy rate. Beginners after training have shortened latency of evoked P1, P3 from the corresponding brain regions slightly shorter, decreased the amplitude of P1, P3 slightly.Through analysis of the results, this study comes to the conclusion that:(1) Elite Sanda athletes, in the general situation, spend more psychological resources during visual search with high concentration of attention, thereby ensuring a rapid and accurate response; Task difficulty doesn't affect the searching speed, but with the degree of task difficulty increased, the consumption of psychological resources also increased. (2) Elite Sanda athletes made the subtly processing of the effective attack point with more psychological resources, thus enhancing the speed and accuracy of visual search; The increase of task difficulty reduced the efficiency of visual search and extended the process of cortical activation, increased the consumption of psychological energy. (3) Skilled motion-recognition of elite Sanda athletes effectively inhibit the interference of irrelevant stimuli with consuming more psychological resources, make the attention focusing on key information, so as to quicken the speed of information matching, thus improve the efficiency of skilled motion-recognition; The more psychological resources, the higher rate of accuracy. (4) Elite Sanda athletes spend more psychological resources in the early period of pre-judgment with high degree of attention concentration and fast activation speedof mental pattern from the memory system, thus enhancing the efficiency of pre-judgment; The greater the amount of information to judge, the more psychological resources used and the higher rate of accuracy of cognitive processing. (5) Perception training of special situation based on visual search and pre-judgment makes beginners to grasp the economic and reasonable search strategies, effectively improve the efficiency of pre-judgment.Based on the above results, the main theoretical contributions of this study are: First, the study regards the perceptual prediction as the typical information processing. Through the resaerch on each cognitive stage of perceptual prediction process, the study systematically reveals of cogntive features and neural mechanism of excellent Sanda athletes in the course perceptual prediction, expands the idea of perceptual prediction research. Second, the study applied a new experimental model and technique with a series of experimental researches conducted in the field of cognitive research in sports. Among those, simulating the sport situation together with the technique of eye movements recording and event-related potentials not only improved the ecological validity, but also revealed the cognitive feature of sports experts from the behavior and the neurophysiological level. Finally, this study reveals the cognitive characteristics and possible mechanisms of Sanda athletes in the stages of visual search, movement identification and pre-judgment, discusses the ionfluence of facotrs like the degree of task difficulty, types of materials on sports cognition and neural mechanism, confirmed that video-based prejudgment training for the special siotuation can not only generate training effect on the behave level, but also moderately affect the law of neural activity. These findings enrich the theoretical outcome of perceptual prediction and extend event characteristics of the research in this field...