The Mechanism Of Dual-task Processing Modulated By Reward

As one of the commonly used ways of thinking in daily life,dual-task processing plays an important role in advanced cognitive activities such as planning and decision-making.The traditional dual task paradigm usually presents two different types of task stimuli at the same time,requiring individuals to perform task responses and then explore the interference between tasks.However,such a traditional dual task paradigm is difficult to explain the task that requires working memory retention and single task.This type of dual task is called branching.In order to solve this problem,the researchers introduced branching paradigm to study dual-task processing involving working memory and attention resource allocation,how individuals perform resource allocation between tasks and how the process is realized has caused researchers' thinking.At present,the research on dual tasks has achieved rich research results,and researchers are extremely concerned about how individuals perform the processing of dual tasks and the factors affecting the adjustment of the processing process.As an external motivation,reward can regulate individual cognitive processing activities,prompt individuals to adjust their behavioral goals in time,maintain task processing status,and further promote the generation of target behaviors.Then,under the adjustment of rewards,how individuals perform dualtask processing and reward coding has become a topic worth exploring.In this study,we combine reward stimulus and branching to study the processing and brain mechanism of branching dual task under the influence of reward.This study includes two experiments.In the first study,we study the branching process under the influence of reward at the behavioral level.We adopt the experimental design of 2(task type: branch condition,switching condition)× 2(first task reward: large and small)× 2(second task reward: large and small)to explore the motivation of reward to single task and branching task.The research results show that dual-task processing has additional psychological processing than single-task processing;rewards can effectively drive the performance of single-task processing,but rewards may impair the performance of dual-task processing.With the increase of the reward of the second task,the reaction time of the dual task processing tends to increase.In the second study,we combine fmri technology to explore the brain mechanism of dual-task processing and the dichotomy effect of reward coding.The results found that the frontopolar cortex,inferior frontal gyrus,and insula and other brain regions were significantly activated under branching conditions.The additional mental process of branch dual tasks involves dual task coordination,maintenance of working memory,and attention distribution,and this mental process is mainly related to brain regions such as frontopolar cortex,IFG,and insula;reward motivation can effectively drive single-task behavior Performance,with the increase of reward,the activation level of the striatum responsible for reward coding is enhanced.In the process of dualtask processing,as rewards increase,reward-related brain regions are not significantly activated.However,the PFC responsible for coordinating subtask processing and the DLPFC activation involving working memory tasks are enhanced,but no individual's improved behavioral performance has been found.Under the influence of rewards,individuals need to pay more cognitive efforts to perform dual task processing mission accomplished.According to the results of Study 1 and Study 2,compared with single-task processing,there are more brain regions mobilized in dual-task processing;rewards can effectively drive single-task processing,but when complex dual-task processing is involved,more cognitive effort is required due to reward.This study further explores the process of dual-task processing under the adjustment of rewards,enriches previous research on rewards and dual-task processing,and adds new experimental research evidence to it.