The Cognitive And Neural Mechanism Of The Self-control Effects On Procrastination

Procrastination is a self-regulation failure,referring to the voluntary but irrational delay of an intended course of action despite the knowledge of the negative consequences for doing so.Procrastination also is a prevalent problematic behavior that causes harm to academic performance,mental well-being,health and social economics.Therefore,systematical explorations conducted on procrastination and its intervention can spark profound significance both in theory and practice to personal achievement and social prosperity.Considerable researches have indicated that self-control is negatively correlated with procrastination,and can help reduce procrastination.However,much less known is the neural basis underlying the effect of self-control on procrastination.Moreover,the temporal decision model(TDM)for procrastination posited that the use of self-control can modulate the competition between the task negative engagement utility and task positive outcome,to affect the decision about to procrastinate or act timely.But no study has investigated the cognitive mechanism of self-control effects on procrastination.Hence,the present study pretends to combine structural and resting-sate magnetic resonance imaging(MRI)methods to explore the neural basis of self-control effects on procrastination,and further clarify the mechanism of this effect using a neural modulation technique.To be specific,Study 1 would utilize the voxel-based mophometry(VBM),resting-state functional connectivity(RSFC)to explore the neural basis underlying the effect of self-control on procrastination.In Study 2,we would use a high-definition transcranial direct current stimulation(HD-tDCS)technique to specify possible mechanisms of self-control effects on procrastination:whether self-control can reduce procrastination via regulating negative feelings to tasks or via increasing the concerns for task incentive outcomes or via modulating these two factors simultaneously.In Study 1,we first explore the behavioral correlation between self-control and procrastination.Then the neural anatomical basis of self-control was identified using VBM analysis.Based on the structural basis of self-control,utilizing the RSFC analysis,we also identify the neural basis of procrastination.Finally,the neural basis underlying the effect of self-control on procrastination wasinvestigated employing a mediation analysis.Furthermore,we also conducted a structural modeling equation analysis to specify the neural circuits of that how self-control affects procrastination.The results showed that:(1)self-control was negatively correlated with the procrastination.(2)the VBM analysis found that self-control have significant positive association with the gray matter volume(GMV)of left dorsolateral prefrontal cortex(lDLPFC).(3)The RSFC results revealed that FC between lDLPFC and bilateral orbitofrontal cortex(lOFC,left orbitofrontal cortex;rOFC,right orbitofrontal cortex),and right medial frontal gyrus(rMFG)were negatively related to the procrastination.(4)the mediation analysis suggested that FC between lDLPFC and bilateral OFC,and rMFG mediated the impact of self-control on procrastination.(5)the structural modeling equation analysis found that the FC between lDLPFC and bilateral OFC,and the FC between lDLPFC and rMFG could be a mediating latent variable,entering into the model and mediating partly the effect of self-control on procrastination.These results suggested that lDLPFC is a core brain region accounts for self-control,and the FC between lDLPFC and bilateral OFC,and rMFG are neural correlates underlying the effect of self-control on procrastination.The FC between lDLPFC and bilateral OFC can represent the regulation of negative emotion to procrastinating tasks,whereas the FC between the lDLPFC and rMFG represents the valuation of task outcomes value.This uncovers that self-control may reduce procrastination through the cognitive processes of emotion regulation and value evaluation..In Study 2,combining a within-and between-subject mixed design,HD-tDCS stiumlation was imposed over the DLPFC to explore whether enhanced self-control can reduce procrastination via modulating negative feelings to tasks and the value of task outcomes.In detail,103 participants were randomly assigned to accept anodal HD-tDCS either over the left DLPFC(lDLPFC),right DLPFC(rDLPFC),or sham stimulations on the two same brain regions.Of note,four groups showed no significant group-difference.Based on the self-reported tasks,participants finished a series rating tasks,including the ratings indicated towards task aversiveness,task outcomes and the willingness to execute tasks within 24 hours.The results suggested that:(1)the willingness to execute tasks increased significantly only after the left DLPFC stimulation,while the right DLPFC and two sham stimulation groups showed no pre-posttest differences in task-execution willingness.(2)and in left DLPFC stimulation group,compared to the baseline,participants' ratings towards task aversiveness decreased significantly,and they showed an increased ratings on task outcome value after stimulation.(3)our mixed model analysis also revealed that the increment of task-execution willingness can be explained by the decrease in task aversiveness and the increase in task outcome value.These results indicated that left DLPFC stimulatio can boost the execution willingness in real-life tasks,and this is mainly implemented by,decreasing the task aversiveness and increasing the concerns on task incentive outcomes.Taken together,the current study reveals that t:(1)the lDLPFC is a key brain region responsible for self-control,and the FC between the lDLPFC and bilateral OFC,rMFG is the neural basis of self-control effects on procrastination.The FC between lDLPFC and OFC can represent the negativeemotion regulation to tasks,whereas the FC projecting from lDLPFC to rMFG correlates intimately with the evaluation of task outcome value.This indicates that self-control affect procrastination through cognitive processes of emotion regulation and value evaluation.(2)Anodal HD-tDCS stimulation imposed over the lDLPFC can temporarily increase the willingness to execute tasks.The increment of task-execution willingness can be attributed to that enhanced self-control can help down-regulate task aversiveness and increase the concerns for task incentive outcomes.In this vein,this study demonstrates that self-control can reduce procrastination proneness by modulating task aversiveness and outcome value.As a whole,the present study clarifies the neural basis accounting for the self-control effects on procrastination based on structural and resting-state MRI methods,and is the first one specifying the cognitive mechanism of how self-control affects procrastination.This work sparks important theory significance on the improvement of the cognitive neural mechanism of how self-control reduces procrastination,also provides new insights on the non-invasive neural intervention of procrastination.