How global and local task contexts influence task-set inertia in dual tasking.

Cognitive control must be flexibly adjusted when task demands change, yet task-set inertia can impair performance by keeping previously relevant task sets active. This study investigated task-set inertia using a hybrid psychological refractory period paradigm, combining a visual-vocal short-term memory task with an auditory-manual reaction time task. We manipulated the stimulus-onset asynchrony (SOA: 100 vs. 1,000 ms) and the relevance of the visual-vocal short-term memory task (task load: report the stimulus vs. ignore the stimulus). In Experiment 1, task load varied unpredictably (trial by trial) or predictably (in blocks). In Experiment 2, we implemented blocks with majority report or majority ignore trials (75% respectively) to examine how global task context influences task-set inertia. Results showed the expected SOA effect in report conditions, with worse performance in the auditory-manual reaction time task at short compared with long SOA. This SOA effect suggests a processing bottleneck between short-term memory consolidation of the visual target and response selection for the auditory target. The SOA effect persisted (but was smaller) in ignore trials, indicating task-set inertia. This residual SOA effect was modulated by the previous trials' task load, with a larger SOA effect when the previous trial was a report compared with an ignore trial. Additionally, the residual SOA effect almost disappeared in predictable ignore blocks and was modulated by the proportion manipulation, showing a larger SOA effect in majority report blocks. These findings show that both global and local task contexts influence task-set inertia, demonstrating that task sets are context sensitive and show involuntary persistence. (PsycInfo Database Record (c) 2026 APA, all rights reserved).