Semantic association ability mediates the relationship between brain structure and human creativity.

Creativity involves the ability to associate relatively weak or distant semantic components and combine them into novel and useful objects. Few studies have explored the brain mechanisms underlying semantic associative ability and its relationship with creativity based on semantic distance. In this study, the chain free association (CFA) task was performed, and semantic distance was quantified to measure individuals' semantic association ability, while the alternative use test (AUT) and creative activity (CAct) tasks were performed to measure creative ability. The behavioral results revealed a significant positive correlation between semantic distance and creativity. The voxel-based morphometry (VBM) analysis found the neural structural basis of semantic distance. Indeed, semantic distance was positively correlated with the gray matter volume (GMV) of the left posterior inferior temporal gyrus (LpITG), which is associated with visual word learning, semantic knowledge retrieval, and semantic memory, in addition to divergent thinking and creative traits. A mediation analysis showed semantic distance mediate the relationship between the regional GMV of LpITG and human creativity. Effectively, highly creative individuals with high regional GMV in LpITG were observed to have higher capacity of spontaneous association process. These findings shed light on the dedication of the brain areas related to remote semantic connectivity to creative thinking via individuals' spontaneous semantic association ability.