Random rewards reduce task-switch costs

Task switching is effortful as it requires overcoming habitual task sets and reconfiguring new ones. Smaller switch costs can facilitate productivity and efficiency in modern work environments, where multitasking is crucial. However, the mechanisms to reduce switch costs are not fully understood, limiting reliable enhancement of this skill through interventions. While recent perspectives have hypothesized that noncontingent, or random, rewards could reduce switch costs, this has yet to be demonstrated. This study documented four experiments investigating the impact of random rewards on switch costs using a cued task-switching paradigm. Specifically, participants received rewards unrelated to the task, presented as gifts randomly at the end of some trials but not others. Results from all four experiments consistently showed that random rewards led to smaller switch costs compared to no rewards. However, this reduction was due to significant slowing after random reward presentations on both subsequent switch and repeat trials. Experiment 2 demonstrated that contingency played a role, with smaller switch costs observed only in the random reward condition, not in the performance-contingent reward condition. Experiments 3a and 3b further showed that reduced switch costs occurred only in the random reward condition, not in the oddball condition, despite both involving unexpected visual events, suggesting that the value of random rewards is critical. These findings provide initial evidence that random rewards can reduce switch costs, manifesting as post-reward slowing on both switch and repeat trials. (PsycInfo Database Record (c) 2025 APA, all rights reserved).