Task Conflict Biases Decision Making

The present research explores decision making in multitasking, investigating how people make optimal decisions between tasks. Empirical evidence suggests that difficulties in task performance (i.e., response conflict within a task) can bias decision making. Here we investigate whether also conflict between task representations can tune choices away from conflict-associated tasks. Using a combined forced/freechoice task-switching design, we tested whether task conflict that arises because of proactive interference of previously activated tasks biases task choice. We compared free-choice decisions between 3 tasks after forced-choice sequences that instigated either high task conflict (task sequences of type ABA, in which persisting inhibition needs to be overcome because one switches back to a just-abandoned task) or low task conflict (task sequences of type CBA). Results of 2 experiments (N = 16; N = 32, preregistered) showed that participants were more likely to switch away from the previously performed task after high than after low task conflict. Furthermore, participants preferably selected the task that suffered least from task conflict and/or proactive interference. In addition, a third experiment (N = 32) confirmed that this bias in task selection could not be explained in terms of randomness heuristics. These results suggest a close link between decision making and performance in multitasking.