Research paperThe role of ventromedial prefrontal cortex volume in the association of expressive suppression and externally oriented thinking

- The vmPFC is the neural base of expressive suppression (ES) and externally oriented thinking (EOT).
- ES is associated with EOT through vmPFC volume.
- There are gender differences in both the self-reported scores and structural correlates of ES and EOT.

BackgroundStudies have suggested that expressive suppression (ES) is linked to externally oriented thinking (EOT) through the ventromedial prefrontal cortex (vmPFC), and there are gender differences in their association. The present structural magnetic resonance imaging study was to investigate the neural bases of ES and EOT and their association in females versus males in a Chinese college sample.MethodsA total of 142 participants (83 females) were enrolled, and they completed the ES subscale of the Emotion Regulation Questionnaire, 20-item Toronto Alexithymia Scale, and anatomical scanning. Voxel-based morphometry, region of interest, and whole brain analyses with peak-level significance (family-wise error corrected at p < .05) were conducted to investigate the association of gray matter volume (GMV) variations with ES and EOT. A bootstrapping analysis was conducted to examine the role of vmPFC volume in the ES-EOT association.ResultsThe ES scores were positively linked to the GMV of the vmPFC in females and negatively related to right dorsolateral PFC volume in males. The EOT scores were positively correlated with the GMV of the vmPFC in females and supplementary motor area in males. Furthermore, vmPFC volume mediated the relationship between ES and EOTLimitationsThe cross-sectional design limited causal conclusions.ConclusionsThe vmPFC may be the only neural base of ES and EOT and their association. In addition, these results were sex-specific.