Volumetric evidence of the mediating role of mental imagery in episodic memory effect on divergent thinking

Functional imaging studies have indicated that divergent thinking involves the cooperation between episodic memory and mental imagery. Moreover, divergent thinking was also demonstrated to rely on inhibition to suppress inappropriate information. Here, a mediation analysis was used to investigate the comprehensive associations between volumetric differences in regions of inhibition, episodic memory, and mental imagery, and performance differences in divergent thinking in 125 healthy individuals. Regions of interest were selected using the Neurosynth meta-analytical database. We found that volumetric differences in the left calcarine (a region involved in mental imagery) mediated the association between volumetric differences in the left parahippocampal (a region involved in episodic memory) and task performance in divergent thinking. Further analysis showed that volumetric differences in the right insula/supramarginal regions (regions involved in inhibition) were associated with divergent thinking through their impact on the volumetric differences in the left parahippocampal and left calcarine. Our results provided volumetric evidence of the mediating role of mental imagery in episodic memory effect on divergent thinking, as well as the promotion of inhibition in these relationships.