Magnetic Resonance Imaging Study Of The Effect Of TMS Intervention On Semantic Cognition In The Left Inferior Frontal Gyrus

Language research is one of the important ways to explore human nature and understand human existence.Semantic cognition refers to the process and representation of human understanding and use of the meaning of words,images,objects,and other things.Neuroimaging studies have shown that the left inferior frontal gyrus plays an important role in semantic cognition,but the neural mechanisms still need to be studied.In addition,the magnetic resonance structural basis of semantic cognition and the semantic cognitive network in the resting state under the intervention of transcranial magnetic stimulation(TMS)are not fully studied.Therefore,this study combines TMS and magnetic resonance imaging technology to explore the semantic cognitive function of left inferior frontal gyrus virtual impairment in healthy subjects,and verifies the results of this study using an open database.This study used semantic and numerical judgment tasks to analyze the behavioral and resting state magnetic resonance differences of participants under baseline,left inferior frontal gyrus true stimulation,left inferior frontal gyrus sham stimulation,and vertex true stimulation conditions.The behavioral results showed that compared to the control group,after TMS intervention in the left inferior frontal gyrus,the significant difference in response time between semantic and numerical judgment tasks disappeared,and the overall accuracy decreased.Magnetic resonance data analysis mainly explores semantic cognitive networks through voxel based morphological analysis,resting state local brain activity,functional connectivity,and graph theory.The results are as follows:1.The results of voxel based morphological analysis show that the gray matter volume of the left opercular part of inferior frontal gyrus,left temporal pole,and right lingual gyrus are positively correlated with semantic and numerical efficiency scores,indicating the important role of the left opercular part of inferior frontal gyrus in semantic cognition,and providing evidence for the possibility of shared neural basis for semantic and numerical processing.2.The resting state results showed a negative correlation between the low-frequency amplitude of the left opercular part of inferior frontal gyrus and the semantic efficiency score in the baseline group.The functional connectivity results showed extensive functional connectivity between the left opercular part of inferior frontal gyrus and bilateral frontal,temporal,and parietal brain regions.The results of the open database show that the low-frequency amplitude of the left opercular part of inferior frontal gyrus is negatively correlated with the picture vocabulary test scores.In addition,the results also show that the right supramarginal gyrus and the left middle temporal gyrus play an important role in semantic cognition.3.The resting state results of TMS intervention in the left inferior frontal gyrus showed that after true stimulation,the low-frequency amplitude of the left inferior parietal lobule increased,while the low-frequency amplitude and fractional low-frequency amplitude values of the left lenticular putamen decreased.The functional connection between the left inferior frontal gyrus,the left superior temporal gyrus and the supramarginal gyrus was enhanced,and the functional connection between the left inferior frontal gyrus and the right anterior cuneiform lobe was weakened.The graph theory results indicate that the brain regions with changes in node attributes after TMS stimulation are mainly in the right hemisphere,where the clustering coefficient and local efficiency of nodes in areas such as the right superior temporal gyrus and insula decrease,while the efficiency of nodes in the right temporal pole increases.In summary,this article combines TMS and magnetic resonance imaging technology to reveal the different effects of the left opercular part of inferior frontal gyrus on semantic cognition in terms of structure and resting state,as well as the changes in the resting state semantic cognitive network when the left inferior frontal gyrus is virtual damaged,providing new possibilities for the study of controlled semantic cognitive frameworks.