The Cognitive And Neural Mechanism Of Decision Model Of Procrastination

Procrastination,which refers as the voluntary but irrational delay of intended course of actions,is a widespread behavioral problem that can be harmful to procrastinators’ work efficiency,academic performance and psychological well-being across different time and situations.Although previous researches have well specified various personality traits associated with individual differences in procrastination tendencies,the basic decision progress of procrastination still remains unknown.As any attempt to procrastinate tasks inevitably involves the decision between “doing it now” or “doing it later”,this kind of decision can be considered as a key component of predicting procrastination.Thus approaches about predicting procrastination can be further simplified as a decision making process of determining doing things now or doing things later.In order to disclose the cognitive mechanism of deciding “do it now or later”,a decision model of procrastination proposed that(1)Motivational competition between procrastination and timely engagement is the rooted process for determining to prolong a task or not;(2)this motivational combat can be simplified as comparison between averseness of engaging in task and rewards(or punishments)from the task;(3)last but not least,putting off an annoy task to have it’s utility discounted is the reason for procrastination.In order to test the theory of decision model of procrastination,we conducted study 1 which intended to use the engaging utility and outcome utility of a task to predict it’s task decision with the time delay increased.Additionally,in order to disclose the relationship between the neural representation of a task or its corresponding outcome and the task procrastination,we have participants in study 2perceive both procrastinated and non-procrastinated tasks,as well as their corresponding outcomes,in an unconstrained way during f MRI scanning.In short,we utilized both behavioral experiment and f MRI to explore(1)the cognitive mechanism of decision about procrastination,(2)the neural substrate of predicting task procrastination with neural signal of task and outcome representation.In study 1,we had participants complied a list of their personal tasks and rated both theengaging utility and outcome utility across different time points(today,3 day,a week,half a month,a month).The result revealed that:(1)procrastinated tasks were associated with negative engaging utility,but non-procrastinated tasks were associated with positive engaging utility;(2)procrastinated tasks have less outcome utility compared with non-procrastinated tasks;(3)task procrastination can be predicted by engaging utility and outcome utility;(4)compared with non-procrastinated tasks,the engaging utility of procrastinated tasks discount more than non-procrastinated tasks.In study 2,we have participants perceive both procrastinated and non-procrastinated tasks,as well as their corresponding outcomes in an unconstrained way during f MRI scanning.Our behavioral result revealed that:(1)procrastinated tasks were associated with negative engaging utility,but non-procrastinated tasks were associated with positive engaging utility;(2)weights on non-procrastinated tasks’ outcomes were significantly higher than procrastinated tasks’ outcomes and engaging of procrastinated tasks were rated as more negative than non-procrastinated tasks;(3)participants accessed thoughts about procrastinated tasks and thoughts about non-procrastinated tasks in an unequal way,yielding a task-outcome gap.Specifically,more thoughts came up when constructing a non-procrastinated task than constructing a procrastinated task when doing free association.Moreover,the neural imaging result revealed that:(1)compared to baseline,we found an upregulation of neural value signals in the putamen and anterior insula during outcome construction,which were separately correlated with desired outcomes and aversive outcomes;(2)BOLD signals of outcome valuation were negatively correlated with task procrastination;(3)a conjunction analysis showed that activations in task construction and outcome construction overlapped extensively in bilateral putamen,left insula and bilateral hippocampus,and a regression analysis revealed that the hippocampus was well explained by outcome related thoughts rather than task related thoughts,suggesting that participants associated the tasks with it’s potential outcomes during constructing task relevant thoughts;(4)a regression analysis revealed that the aforementioned task-outcome gap was associated with decreased signals in the putamen which should represent the potential outcome value during task construction,indicating that the inequality in task-outcome accessibility of procrastinated tasks is likely caused by the insufficiently established task-outcome association;(5)using a psychophysiological interaction analysis(PPI),we found that a non-procrastinated task was associated with increased couplings between hippocampus with caudate.Model comparison revealed that a Gap model which based on outcome-task gap in highly procrastinated tasks fits the Hip-Cau coupling best,indicating that the Hip-Cau coupling was related to task-outcome association.Overall,current study found(1)task procrastination can be predicted by the comparison of engaging utility and outcome utility;(2)individuals procrastinate tasks to have the negative feelingsof engagement of tasks discounted;(3)there was greater task-outcome gaps for procrastinated tasks than non-procrastinated tasks,which stems from a decreased Hip-Cau coupling during task construction.First,our finding directly supported the theory of decision model of procrastination,and furthered the understanding of cognitive mechanism of decision of procrastination.Second,those results first revealed that task procrastination was related to task-outcome gap during free construction.Last but not least,decision model of procrastination confirmed that the important role of outcome utility and engaging utility in procrastination,which supplemented theoretical evidences of value-related interventions to inhibit procrastination.