The Cognitive And Neural Mechanism Of Trait Rumination Affecting Procrastination

Procrastination is defined as a voluntary but irrational postponement of an intended action,despite the fact that the delay may have worse consequences(Steel,2007),and is regarded as a personality with cross-time and cross-situation stability which not only impairs people’s physical and mental health,but also hinder the development and progress of society(Demir & Kutlu,2018).Therefore,from the perspective of behavioral and neuroscience,a systematic study of the cognition mechanism underlying procrastination not only has theoretical significance,but also provides important practical implication for the effective prevention and intervention of procrastination,thus contributing to improvement of individuals’ lives and the betterment of society.Previous research has shown a stable positive correlation between trait rumination,a personality trait strongly associated with negative self-related emotions,and procrastination(Rebetez et al.,2018).However,we do not have a clear understanding of the cognitive neural mechanisms by which trait rumination influences procrastination.Rumination causes individuals to repeatedly ponder and analyze self-relevant negative experiences and induce negative emotions,thus negative cognitive bias and emotional dysregulation are core cognitive features of high trait ruminators,showing increased negative episodic future thinking and a deficit in adaptive emotion regulation.The temporal decision model of procrastination indicates that people tend to procrastinate when the perceived task aversiveness exceeds the value of positive outcome,and that the central purpose of procrastination is to discount the task aversiveness,both episodic future thinking and emotional regulation play an important role during this process(Zhang & Feng,2020).For high trait ruminators,the presence of negative cognitive bias during the assessment phase of procrastination tasks might lead them to construct task-related negative scenarios.Combining the 2(imaginary direction: outcome versus engagement)×2(emotional valence: negative versus positive)model of episodic future thinking(the “2×2 model”),it can be inferred that negative episodic future thinking of a task includes anticipation of a negative process(e.g.difficulties in executing the task)and a negative outcome(e.g.task failure).In contrast,when dealing with the task negative emotions induced by negative episodic anticipation,high trait ruminators may have difficulty in regulating negative affect such as task aversion due to their lack of emotion regulation ability.Therefore,trait rumination may exacerbate procrastination through amplifying negative episodic future thinking and undermining emotion regulation ability.In order to explore the specific mechanism underlying the influence of trait rumination on procrastination,our research combined behavioral measures and neuroscientific analysis techniques to investigate the cognitive mechanisms and neural basis of the relationship between trait rumination and procrastination through Study 1 and Study 2,respectively.In Study 1,we aimed to explore the cognitive mechanisms by which trait rumination affects procrastination.Ruminative Response Scale(RRS,Treynor et al.,2003),General Procrastination(GPS,Lay & Silverman,1996),Regulation of Emotion subscale of Wong Law Emotional Intelligence Scale(WLEIS-ROE,Wong & Law,2002)were used to measure trait rumination,procrastination and emotion regulation ability in 241 subjects.Meanwhile,utilizing the free construction of episodic future thinking paradigm(Yang et al.,2021),required subjects to imagine freely about the execution process and outcomes of procrastination tasks,and write their imagined contents down.Then,based on the 2×2 model,three independent coder encoded these contents to obtain the their episodic future thinking characteristics(i.e.,scores for each dimension of episodic future thinking,including negative process,positive process,negative outcome,and positive outcome of tasks).Subsequently,subjects need to evaluate of procrastination frequency and task aversiveness for each task subjectively.Afterwards,we conducted a correlation analysis and structural equation modeling to investigate the cognitive mechanism of trait rumination influencing procrastination.The findings are as follows:(1)trait rumination was positively correlated with procrastination;(2)trait rumination affected task procrastination through episodic future thinking and emotion regulation pathways,where(a)the episodic future thinking pathway suggested that trait rumination increases individual’s negative episodic future thinking about task engagement and induces higher levels of task aversiveness,leading to frequent procrastination,and(b)the emotion regulation pathway suggested that trait rumination impairs individual’s adaptive emotion regulation,making it difficult for them to regulate task aversiveness,leading to frequent procrastination.Above all,high ruminators might have difficulty in effectively regulating task aversiveness due to negative episodic future thinking bias that exacerbates negative affect,as well as emotional dysregulation,which may lead to procrastination,explaining the potential cognitive mechanism by which trait rumination influences procrastination.In Study 2,we aimed to explore the neural basis by which trait rumination affects procrastination.Firstly,602 subjects were required to finish RRS scale and GPS scale to measure trait rumination and procrastination,and we also collected their structural and resting-state brain imaging.Secondly,voxel-based morphometry(VBM)was used to investigate the structural basis of trait rumination.The resting-state functional connectivity(RSFC)analysis was then conducted to identify the resting-state functional connectivity associated with trait rumination,using the brain areas identified in VBM analysis as seed areas.Finally,a mediation analysis was employed to probe the influence of trait rumination on procrastination.The findings are as follows:(1)trait rumination was positively correlated with procrastination;(2)the VBM results showed trait rumination was negatively correlated with gray matter volume of the insula;(3)the RSFC results revealed a negative association of the left insula-lm SFG(left medial superior frontal gyrus)functional connectivity with trait rumination;(4)trait rumination could completely mediate the relationship between left insula-lm SFG functional connectivity and procrastination.Above all,the neuroimaging finding of Study 2 not only point out that both the left insula and lm SFG are the key brain areas for trait rumination,but more importantly suggested that the weaker the left insula-lm SFG functional connectivity,which is involved in emotion regulation,the higher the level of trait rumination in individuals,which in turn leads to more procrastination.In summary,this study found that:(1)trait rumination can exacerbate task aversiveness by increasing negative episodic future thinking about task engagement(episodic future thinking pathway)and impairing emotion regulation(emotion regulation pathway),there by contributing to the occurrence of procrastination;(2)trait rumination can completely mediate the relationship between left insula-lm SFG connectivity and procrastination.The left insula-lm SFG connectivity is involved in the top-down regulation of negative emotions,and thus emotion dysregulation may be a key pathway through which trait rumination affects procrastination.This study has theoretical implications in terms of identifying the cognitive and neural mechanisms by which trait rumination affects procrastination at both the behavioral and neural perspectives.In addition,the finding can be applied to the design of intervention program,providing a new way of thinking to improve the procrastination problem of high ruminators.