Research On Construction Of Cerebrum Structure Network And Motor System Plasticity Based On Bayesian Theory And Graph Theory

The plasticity of the brain is an ability which can change the structure and function of the nervous system under the influence of external conditions and experience.With the development of brain science,big data and artificial intelligence,the exploration of the brain is becoming more and more deep,which makes the plasticity of brain become one of the hottest issues.As a result of long-time training,athletes provide a very good research object for the research of cerebrum plasticity.At present,there are few researches on athletes at home and abroad.Using the principle of water molecular imaging based on Brownian movement to establish a mathematical model,this thesis mainly utilizes athletes' structural imaging data and diffusion tensor imaging data to calculate and analyze relative metrics and establishes small world network of the cerebrum,which tries to find brain plastic changes caused by training in order to provide new enlightenment for the athletes to reveal the mechanism of plasticity from the system level.The main work is as follows:1.We calculate the Voxel Based Morphometry gray matter density and cortical thickness to explore the differences between athletes and ordinary people in gray matter density and cortical thickness,the results show that in the cerebellum,left cingulate gyrus and the left parietal lobe,gray matter density is greater than that of ordinary people.In addition,according to the result of gray matter density,we calculate covariance of the left and right cerebrum,which combine with the result of fiber from probabilistic tracking method and get the result of high correlation with the left and right cerebrum in both athletes and ordinary people.2.We use the probabilistic tracking method of white matter fiber to reconstruct the fiber distribution of the cerebrum and calculate the related metric: Fractional Anisotropy(FA),which lays the foundation for the subsequent establishment of the structural network and the small world network.Student's t test is used to find the differences between athletes and ordinary people on white matter fibers,including but not limited to fiber strength,fiber distribution and so on.The results show that there were significant differences in the cerebrum motor regions,and the left and right cerebrum show certain relative symmetry.3.Based on the previously calculated character—FA,the structural network small world model is established to find the difference between the athletes in the cerebrum structural network and the ordinary people.The results show that there obviously exist small world properties in both athletes and ordinary human.In the small world topological attributes clustering coefficient and local efficiency,athletes were significantly higher than ordinary people,which means the degree of polymerization between athletes' brain regions is more closely and more tolerant of their brain network.In the local topological index,in the precentral gyrus,thalamus,calcarine cortex around the top edge node,angular gyrus,middle temporal gyrus,the nodal shortest path efficiency and nodal degree increase significantly;the nodal degree of Inferior parietal,but supramarginal and angular gyri and middle temporal gyrus has decreased significantly.The rise and fall are related to the long-time training of athletes,which the cerebrum plasticity has been further verified.