Time expectancies in dual tasking: Evidence for proactive resource sharing?

The present study explored whether dual-task performance is affected by deviations from the expected time point of a secondary task. In two psychological refractory period experiments, participants responded to two tasks, separated by either a short or long delay. In contrast to traditional dual-tasking studies, however, the identity of Task 1 probabilistically predicted the delay after which Task 2 would occur. Violations of these expectations impaired performance in both Task 2 and Task 1. For Task 2, this effect was more pronounced when Task 2 occurred unexpectedly early, while for Task 1, it was more pronounced when Task 2 occurred unexpectedly late. The results are consistent with the notion that processing resources can be shared, and that even in the absence of Task 2, some resources are withheld from Task 1, based on early available Task 1 features. (PsycInfo Database Record (c) 2023 APA, all rights reserved).