Investigation of reward-related processing improvements in dual-task situations

Abstract

Evidence from single-task studies suggests that reward improves cognitive performance, yet its role in dual-tasking (DT) remains unclear. This dissertation addresses four open questions: (1) which DT processes are affected by reward, (2) whether reward effects transfer between tasks, (3) whether reward strategies can be flexibly adapted, and (4) whether reward-related improvements reflect mere preparation. Using the psychological refractory period (PRP) paradigm with reward prospect for task 1 (Study 1) or task 2 (Study 2), results showed that reward improved pre-motoric processes in task 1 and transmitted benefits to task 2. Study 3 applied trial-wise reward cues and varied the cue–target interval (CTI), showing that while longer CTIs enhanced performance, reward effects extended beyond preparation. Together, the findings suggest that reward enhances DT performance, involves inter-task transmission, and cannot be explained by preparation alone.