Task switching (psychology)

Task switching, or set-shifting, is an executive function and a kind of cognitive flexibility that involves the ability to shift attention between one task and another. This ability allows a person to rapidly and efficiently adapt to different situations. It is often studied by cognitive and experimental psychologists, and can be tested experimentally using tasks like the Wisconsin Card Sorting Test. Deficits in set-shifting are commonly observed in patients with Parkinson's disease, and in those on the Autism spectrum.

Human behavior and cognition are characterized by the ability to adapt to a dynamic environment, whether in attention, action, or both. This ability to adaptively shift attention and action has been investigated in the laboratory since the first use of the task switching paradigm by Jersild (1927). This paradigm examines the control processes that reconfigure mental resources for a change of task by requiring subjects to complete a set of simple, yet engaging interleaving operations that must be performed in an alternating or repeating sequence.

Performance on these tasks is disrupted when a switch from one task to another is required. This disruption is characterized by a slower performance and decrease in accuracy on a given task A on a trial that follows the performance of a different task B ("alternating" or "switch" trial) as opposed to performance on task A when it follows another trial of task A ("repetition" trial). The difference in accuracy and performance between a task repeat (A-A) and a task switch (A-B) is known as the switch cost. The switch cost remains even when there is ample warning of an upcoming switch, thus it is thought to reflect the functioning of numerous executive control processes ranging from attention shifting, goal retrieval, task set reconfiguration processes, and inhibition of prior task set.

This paradigm assumed that processing is the same on repetition and alternation trials but for the process of switching. Rogers and Monsell (1995) suggested that alternation trials place more demands on working memory because subjects must remember two tasks on alternation trials, but only one on repetition trials. To overcome these problems, the alternating-runs procedure was introduced in which subjects alternate between short runs of different tasks (e.g., AABBAABB). Repetitions occur within runs (e.g., AA, BB), and alternations occur between runs (e.g., AB, BA). Memory load and the requirement for monitoring is the same for repetitions and alternations.

...
Wikipedia