Task inhibition and task repetition in task switching

In task-switching experiments with three tasks, the relative cost of an N2 task repetition (task sequence ABA) compared to a task switch (task sequence CBA) is referred to as N2 repetition cost. N2 repetition cost is assumed to reflect persisting inhibition of a task that was recently switched away from. In two experiments, we explored whether the occurrence of task repetitions has an influence on the size of the N2 repetition cost. The results in both experiments showed a decreased N2 repetition cost in conditions in which task repetitions were possible*independent of whether the occurrence of task repetitions was manipu-lated between subjects (Experiment 1) or within subjects (i.e., block by block, Experiment 2). These results suggest that the occurrence of task repetitions affects the balance of activation and inhibition in task switching. The task-switching paradigm offers a tool for studying the role of cognitive control processes that allow a flexible adaptation of internal settings to changing action requirements. Adopting one internal setting always has to go along with the resolution of interference between competing settings. To give a real-life example, when writing an article, the internal setting has to be set on ‘‘writing’’*which involves the resolution of competition between ‘‘writing’’, ‘‘planning the next weekend’’, and ‘‘reading newspapers’’. Internal settings are also referred to as ‘‘task sets’ ’ (see, e.g., Rogers & Monsell, 1995) and include all relevant components that enable us to perform a particular task (e.g., task relevant stimulus-categorisation rules, category-response rules, corresponding motor programs, etc.). Switching from one task set to another requires the activation of the relevant task set Correspondence should be addressed to Andrea M. Philipp, RTWH Aachen University