The Relationship Between Semantic Network Structure And Creative Thinking And Its Neural Mechanism

Creativity is vital to the development of society and the progress of human civilization.Although there is still no consensus on the definition of creativity,most scholars define it from the perspective of "product".From this perspective,creativity can be simply defined as the ability to produce new and valuable products.Semantic memory is the human memory system responsible for storage of knowledge about the world,including concepts and facts,regardless of time or context,which is of great significance to the study of the mechanism of creative cognitive processing.Creativity,as a high-level cognitive function,has a very complex organizational structure and is influenced by a range of distinct but interacting cognitive activities.It depends not only on bottom-up semantic memory processes but also on top-down executive control.Both the associative theory and the executive theory emphasize the important role of semantic network in creative cognitive processing.In recent years,although there has been a lot of current studies on the relationship between creative thinking and semantic network structures has been explored.However,previous studies are mostly based on the individual semantic networks constructed in the context of foreign languages such as Hebrew and French.Whether similar results can be obtained in the study of the relationship between semantic networks and creativity in the Chinese system still needs further discussion.In addition,the current researches in this area is only at the behavioral level,and there are few studies on the neural mechanism of individual semantic network,especially the structural basis of brain and neural intervention.Therefore,this study will first explore the relationship between the topological attributes of the semantic network and creative thinking by constructing the individualized semantic network,and then use brain structure imaging to study the potential brain structure foundation basis behind the relationship between them.Secondly,the method of neural intervention will be used to explore the influence of neural activities of brain regions related to semantic network control on individual creative thinking,so as to further reveal the relationship between them.In the first study,two experiments were conducted to explore the relationship between individual-level semantic network structure and creative thinking and the basis of brain structure.Experiment 1 mainly explores the relationship between individual semantic relationship and creative thinking from the behavioral level.To be specific,we firstly,refer To the semantic network construction method proposed by Benedek in 2017.The semantic similarity judgment task was used to ask the subjects to rate the semantic similarity of any two word pairs in 28 cued words,and the semantic network at the individual level was constructed according to the results of this similarity rating.Furthermore,the topological attributes of each individual's semantic network were calculated by graph theory technique,and Pearson's correlation calculation was carried out by combining these indexes with creativity scores,so as to explore the relationship between the structural attributes of semantic network and creative thinking from the perspective of individual differences.The results show that the global efficiency and local efficiency of individual semantic network are positively correlated with each dimension of creative thinking,while the modularization coefficient is negatively correlated with creative thinking score.This indicates that the more creative the individual is,the more flexible,integrated and efficient organizational structure of semantic network they have.Experiment 2 explored the relationship between semantic network structure,creative thinking and brain structure from the perspective of neuroimaging.Specifically,experiment 2 collected T1-weighted structural data of the subjects.Secondly,morphological analysis method based on voxel was used to explore the relationship between different indicators of semantic network and gray matter volume.Finally,a mediation model was established to describe the relationship between individual semantic network information topological attributes,gray matter volume and creative thinking.The results showed that both local efficiency and global efficiency were correlated with the volume of gray matter in brain regions such as temporal pole and inferior frontal gyrus orbital region.The gray matter volume of the left temporal pole and the inferior frontal gyrus orbit affects creative thinking through the global efficiency of semantic network,showing that the larger the volume of left temporal pole and inferior frontal orbital gray matter,the stronger the global transmission capacity of the individual semantic network may be,the faster the efficiency of information transmission between network nodes,and the more creative ideas can be generated by continuously extracting distant semantic concepts.The second study aimed to explore the effect of semantic network related brain regions on creative thinking by intervening neural activities in the brain region of the left inferior frontal gyrus.First of all,the participants were measured on AUT tasks before the experiment to ensure that their baseline level of creativity was equivalent.Secondly,by consulting relevant literature and the results of Study1,the target stimulation brain region was selected as the left inferior frontal gyrus.Previous literature has proved that the inferior frontal gyrus is the core region of semantic control,and this region may also be closely related to the structure of individual semantic network.In the end,the subjects with similar creative thinking scores were randomly divided into three groups: anodic stimulus,cathodic stimulus and pseudo stimulus.The central electrode of the transcranial electrical stimulator was used in the "F7" region of the international 10-20 EEG system.Four opposite electrodes were located about 7.5cm away from the central electrode.The left IFG area was stimulated by 4*1 high precision transcranial direct current stimulation(TDCS)to observe the creative task performance of different groups of subjects.The results showed that the creative thinking scores of the anodic stimulus group were significantly higher than those of the cathodic stimulus group and the pseudo stimulus group.These results indicate that anodic stimulation can significantly improve divergent thinking by changing neural activities in brain regions related to semantic network,which further proves the influence of semantic network on creative thinking.It also indicates that the intervention of t DCS on creative thinking is feasible and has potential promotion value.In conclusion,first of all,this study found that the individual semantic network with high local efficiency and global efficiency and small modularization coefficient can better promote the output of creative thinking.Secondly,the larger the gray matter volume in brain regions such as the left temporal polar and inferior frontal gyrus orbital,the higher the global efficiency of individual semantic network,and the faster the efficiency of information transmission between network nodes,which will promote the creative thinking performance of individuals.Finally,the neural intervention of high-precision TDCS on the subjects also further proved that the changes in semantic network related brain regions did promote creative thinking.In general,this study explores the relationship between semantic network structural attributes and creative thinking from three aspects of behavior,structural image and neural intervention,and discusses the neural mechanism behind it,which is conducive to a comprehensive understanding of the relationship between semantic memory network system and creative thinking.At the same time,it also provides more data support and inspiration for the research on the relationship between semantic network and creativity.