Executive control of cognitive processes in task switching.

TLDR

Four experiments examined task switching by having participants alternate between geometric classification and arithmetic operations, varying task familiarity, rule complexity, and visual cue presence to assess performance. Switching costs rose with rule complexity and fell with task cuing, and the additive pattern supports a two‑stage executive control model where rule activation is slower when moving from familiar to unfamiliar tasks.

Abstract

In 4 experiments, participants alternated between different tasks or performed the same task repeatedly. The tasks for 2 of the experiments required responding to geometric objects in terms of alternative classification rules, and the tasks for the other 2 experiments required solving arithmetic problems in terms of alternative numerical operations. Performance was measured as a function of whether the tasks were familiar or unfamiliar, the rules were simple or complex, and visual cues were present or absent about which tasks should be performed. Task alternation yielded switching-time costs that increased with rule complexity but decreased with task cuing. These factor effects were additive, supporting a model of executive control that has goal-shifting and rule-activation stages for task switching. It appears that rule activation takes more time for switching from familiar to unfamiliar tasks than for switching in the opposite direction.