Linking task selection to task performance: Internal and predictable external processing constraints jointly influence voluntary task switching behavior.

Findings from studies using the voluntary task switching (VTS) paradigm (Arrington & Logan, 2004) suggest that task selection in multitasking can be influenced by both cognitive and environmental constraints. In the present study, we used an adaptive VTS paradigm to directly test whether and how people adapt to these 2 constraints when they are instructed to optimize their task performance. In 5 experiments, the availabilities of stimuli for 2 tasks in a trial changed predictably because the stimulus needed for a task repetition appeared with an SOA that increased linearly with the number of repetitions. Experiments 1a and 1b demonstrated that stimulus availability did not automatically induce switching behavior. Experiment 2 showed that the predictable external constraints were accommodated in participants' switching behavior once participants overcame their reluctance to switch tasks. Experiments 3 and 4 revealed that both switch costs and switch rates were influenced by manipulating the time between trials. Moreover, switch costs and switch rates were correlated across all experiments; and when the time for advanced preparation of task selection was limited (Experiment 1a, 1b, and certain conditions of Experiments 3 and 4), the SOA in task switches approximately matched switch costs. Together, these results point to a link between task selection and performance indicating that participants adapt their task selection behavior to mutual effects of external and internal influences on task performance. We propose that both task selection and task performance can be integrated within a framework of competing multiple task-set activations. (PsycINFO Database Record (c) 2019 APA, all rights reserved).