The neural basis underlying the relation between the action identification level and delay discounting: The medial...

Previous studies have elucidated that action identification level brings ubiquitous effects in human life. The higher identification level is widely associated with future-oriented perspective, goal-directed actions, less impulsivity and so forth. However, little is known about how it relates to delay discounting. To address this issue, we sought to investigate the neural underpinning to understand their relations using voxel-based morphometry (VBM) and resting-state functional connectivity (RSFC) approaches. The behavioral results revealed that higher identification level was correlated with less discounting rate. The VBM results showed that gray matter (GM) volumes in left orbitofrontal cortex (OFC), left medial prefrontal cortex (mPFC) and right superior frontal gyrus (SFG) were positively correlated with action identification level. The RSFC results found that action identification level was positively associated with the functional connectivity between left OFC-left precuneus, and left mPFC-right precuneus respectively. Moreover, the structural equation modeling (SEM) showed that the association between the identification level and delay discounting was completely mediated by coupling of combined left OFC-left precuneus and left mPFC-right precuneus. These findings suggested that the functional communications within these brain regions in valuation and episodic prospection may account for the relationship between action identification level and delay discounting. The results enhanced our understanding of their relations from neural basis.