Training of executive control processes in task switching: Evidence for transfer of training

There is growing evidence that deficits in executive control processes may be ameliorated with training, and that improved performance can transfer to new tasks (Dowsett & Livesey, 2000; Kramer, Larish, & Strayer, 1995; Klingberg, Forssberg, & Westerberg, 2002). A number of studies have reported practice related improvements in the task switching paradigm, a measure of executive function (e.g., Cepeda, Kramer, & Gonzalez de Sather, 2001; Meiran, 1996). These improvements have typically been attributed to benefits in performing the component tasks that constitute a task switch rather than an improvement in the control processes underlying task switching itself (Jersild, 1927; Mayr & Kliegl, 2003; Meiran, 1996; Rogers & Monsell, 1996). However, the existence of generalizable training has never been directly tested. This research attempts to amend this oversight by directly comparing the performance of participants who received multiple session practice on task-switching to those who did not using a pre-test/post-test design. This article presents evidence for training related transfer after moderate amounts of practice in three different task-switching paradigms, an alternating runs paradigm in which tasks switched predictably, a random cued switch in which there was no opportunity for preparation and a random cued switch in which time was given for preparation between the presentation of the cue and target. Transfer of improvement for general switch costs, but not specific switch costs was found for both predictable and randomly ordered switches. However, transfer of training was specific to the paradigm used. Transfer was not seen between the two different types of task switching even when there was time to prepare for a switch. Transfer was no longer seen when a long interval was given for preparation. These results indicate that task-switching performance as measured by general switch costs (mixing costs) can generally improve with repeated practice, and this benefit occurs in the part of the switch cost that can benefit from preparation.