The Impact of Immediate and Delayed Rewards on Task-Switching Performance

BACKGROUND/OBJECTIVES: Switching between different tasks incurs switch costs. Previous research has demonstrated that rewards can enhance performance in cognitive tasks. However, prior studies have primarily focused on the overall improvement in cognitive task performance, with limited research on how different types of rewards function under various task conditions. This study aims to investigate the distinct effects of immediate and delayed rewards on cognitive task performance in different task conditions (repeated trials and task-switching trials) and to explore the underlying neural mechanisms, particularly focusing on how rewards influence attention allocation during the concurrent processing of multiple cues. METHODS: This study recruited 27 college students (average age 19 years old, 10 males and 17 females). A cue-based task-switching paradigm incorporating immediate and delayed rewards was employed. The study examined the effects of immediate and delayed rewards on cognitive task performance in repeated trials and task-switching trials. Event-related potentials (ERPs) were recorded to investigate the neural mechanisms underlying reward effects on attention allocation. RESULTS: Behavioral results indicated that immediate rewards significantly enhanced performance in repeated trials compared to delayed rewards. In contrast, no significant difference between immediate and delayed rewards was observed in task-switching trials. ERP results showed that immediate rewards induced a larger P300 amplitude than delayed rewards under the task repetition condition. No P300 difference was found between immediate and delayed rewards under the task-switching condition. CONCLUSIONS: The findings suggest that rewards enhance task performance by optimizing the allocation of attention to the ongoing task when multiple cues are processed concurrently. When additional resources are required to process task-related cues, there may be insufficient remaining capacity to effectively process reward cues, which could be essential for the optimal completion of the task. These results support the Expected Value of Control (EVC) theory in task-switching scenarios.