The present study aimed to investigate the neural underpinning responsible for the association between emotion regulation and procrastination. The behavioral results revealed that emotion regulation was negatively associated with procrastination. Results from VBM analysis indicated that the higher level of emotion regulation was associated with greater right dlPFC volumes. In addition, the RSFC results revealed that the dlPFC-insula functional connectivity was positively associated with emotion regulation. More importantly, emotion regulation mediated the relationship between dlPFC-insula coupling and trait procrastination. In summary, our findings suggest that the functional connectivity between right dlPFC and left insula might underlie the association between emotion regulation and procrastination.
Behavioral results demonstrated that emotion regulation was negatively correlated with procrastination. Previous studies have shown that people with high emotion regulation ability are able to accurately identify and modify negative emotion to attain long-term goals (Berking and Znof 2008). Besides, the short-term mood repair theory suggested that individuals tend to procrastinate in order to repair immediate short-term negative mood while ignoring task goals (Sirois 2014; Tice and Bratslavsky 2000). When confronting emotional distressing induced by aversive tasks, people with high emotion regulation ability can understand the prompts of their affective states and actively modulate them by more appropriate coping means rather than taking defensive and avoidant strategies (Tice et al. 2001). In addition, based on the temporal decision model of procrastination, procrastination can be regarded as a trade-off between the task aversiveness and the potential future outcomes of this task (Zhang and Feng 2020). Therefore, effective emotion regulation, by which individuals engage in top-down cognitive control over negative emotion, can attenuate task aversiveness, facilitate cognitive performance, and protect individuals from giving up their task goals (Eckert et al. 2016). Thus, unsurprisingly, emotion regulation was negatively associated with procrastination.
The VBM analysis indicated that GM volumes in right dlPFC were positive correlated with emotion regulation. The dlPFC have been described as core nodes of the regulatory network and converging fMRI studies confirmed increased activity of dlPFC during emotion regulation (Buhle et al. 2014; Frank et al. 2014; Rêgo et al. 2015). Previous studies suggested that individuals with emotion regulation disability consistently demonstrated reduced acitivity of the dlPFC during down-regulation of negative emotion, further indicating that dlPFC may be a core brain region in selection, manipulation and inhibition during emotion regulation (Zilverstand et al. 2017; Phillips et al. 2003; Kohn et al. 2014). Moreover, the valence theory of hemisphere-lateralized activity of prefrontal regions has demonstrated that right dlPFC may be particularly involved in negative emotional processing (Davidson 1992; Davidson et al. 1999). This perspective received additional support from brain simulation studies on the right prefrontal cortex (Leyman et al. 2009). For instance, previous studies confirmed that transcranial direct current stimulation targeting right DLPFC enhanced the intentional negative emotion regulation (Wu et al. 2020; Feeser et al. 2014; Smits et al. 2020). Therefore, it is plausible that the right dlPFC might be the main anatomical biomarker of emotion regulation.
The RSFC analysis showed that the dlPFC-insula functional connectivity was positively associated with both emotion regulation. Previous studies have demonstrated that there is tight connection between dlPFC and insula (Andreescu et al. 2015; Steward et al. 2016; Zhang et al. 2022). For instance, previous studies have demonstrated that the abnormal connectivity between dlPFC and insula was related to addiction craving, which is strongly associated with mood and impulse control (Li et al. 2019, 2020; Wang et al. 2022). The dlPFC involved in the frontoparietal network, was the neural underpinning of executive control and adaptive behaviors by top-down regulation of other brain regions, including emotion generation areas such as amygadala and insula (Morawetz et al. 2020; Wang et al. 2022; Yuan et al. 2020). Moreover, several neuroimaging studies have elucidated the key role of insula in encoding negative emotion information and processing negative feelings (Fujino et al. 2016; Simmons et al. 2006; Shiba et al. 2017). In brief, the increased connectivity between dlPFC-insula may facilitate top-down control over aversive affect, thereby guiding better negative emotion regulation. Collectively, the RSFC results suggested that the functional connectivity of the dlPFC-insula, involving top-down regulation circuits, could be the neural correlates for emotion regulation.
Furthermore, the mediation analysis revealed that the functional connectivity between dlPFC and insula had an indirect impact on procrastination through emotion regulation. Specifically, the right dlPFC is considered as a crucial brain area of top-down control over negative mood (Feeser et al. 2014; Leyman et al. 2009). Previous research has shown that the GM volume in right dlPFC mediated the relationship between expression inhibition and procrastination (Wang et al. 2022). Besides, insula is associated with aversiveness and engages in generating and processing negative emotion (Fujino et al. 2016; Simmons et al. 2006). A recent study demonstrated that the aberrant morphological features of insula is associated with high procrastination (Chen et al. 2020). Therefore, the functional connectivity between dlPFC and insula may reflect cognitive control over negative emotion, which is crucial to initiate and sustain goal-directed actions. Moreover, several lines of evidence have suggested that individuals with high emotion regulation ability could allocate resources of cognitive control rationally, thus effectively modifying negative emotions (Eckert et al. 2016). During task completion, they tend to adopt more adaptive coping strategies to reduce task aversiveness and focus on long-term goal pursuing (Berking and Znof 2008). However, procrastinators may have difficulties with emotion regulation, which means they are more likely to give up task goals in order to avoid negative mood without using adaptive emotion regulation strategies, such as cognitive reappraisal (Eckert et al. 2016; Sirois and Pychyl 2013). A growing number of studies have identified that functional abnormalities of emotion regulation were associated with procrastination (Chen et al. 2020; Eckert et al. 2016; Wang et al. 2022). Hence, the FC of the dlPFC-insula, which reflects cognitive control over negative emotion during task completion, could be responsible for the close relationship between emotion regulation and procrastination.
Overall, the present study explored the neural substrates underlying the association between emotion regulation and procrastination. Our findings could provide theoretical insights into neural interventions for procrastination targeting emotion regulation neural circuits. Despite this important contribution, the present research has some limitations. The methods used in this study could not detect causal relationship between emotion regulation and procrastination. To address this, future studies could combine task paradigms and manipulate emotion regulation during task completion to further record actual procrastination behaviors and deeply understand the causal effect. In addition, the findings from the cross-mode-validation (i.e., structural to resting-state imaging) provided primary exploration into the neural substrates underlying the association between emotion regulation and procrastination, which could be improved by further research applying other kinds of technical methods, like task-related fMRI or noninvasive brain stimulation.
In summary, the present study demonstrated that emotion regulation was negatively correlated with procrastination. The results from the VBM analysis showed that the GM volume of the right dlPFC was significantly positively related to emotion regulation. Moreover, the RSFC analysis revealed that the dlPFC-insula connectivity was positively correlated with emotion regulation. More importantly, emotion regulation mediated the relationship between dlPFC-insula functional connectivity and procrastination. In conclusion, this study provides valuable insights from a neural perspective into the relationship between emotion regulation and procrastination. These findings have the potential to inform further research on brain stimulation interventions that target brain regions related to emotion regulation for the purpose of reducing procrastination.