The task-switching paradigm offers enormous possibilities to study cognitive control as well as task interference. The current review provides an overview of recent research on both topics. First, we review different experimental approaches to task switching, such as comparing mixed-task blocks with singletask blocks, predictable task-switching and task-cuing paradigms, intermittent instructions, and voluntary task selection. In the 2nd part, we discuss findings on preparatory control mechanisms in task switching and theoretical accounts of task preparation. We consider preparation processes in two-stage models, consider preparation as an all-or-none process, address the question of whether preparation is switchspecific, reflect on preparation as interaction of cue encoding and memory retrieval, and discuss the impact of verbal mediation on preparation. In the 3rd part, we turn to interference phenomena in task switching. We consider proactive interference of tasks and inhibition of recently performed tasks indicated by asymmetrical switch costs and n-2 task-repetition costs. We discuss stimulus-based interference as a result of stimulus-based response activation and stimulus-based task activation, and response-based interference because of applying bivalent rather than univalent responses, response repetition effects, and carryover of response selection and execution. In the 4th and final part, we mention possible future research fields.Keywords: task switching, cognitive control, interference Human behavior is highly adaptive and flexible in response to changing environmental demands. This flexibility requires complex cognitive control processes, which allow humans to not only respond reactively but also to behave in a more proactive way to achieve goals and to perform tasks. The exploration of the proAndrea Kiesel, Department of Psychology, University of Wiirzburg, Wiirzburg, Germany; Marco Steinhauser, Department of Psychology, University of Konstanz, Konstanz, Germany; Mike Wendt, Experimental Psychology Unit, Helmut Schmidt University, Hamburg, Germany; Michael Falkenstein, Leibniz Research Centre for Working Environment and Human Factors, TU Dortmund, Dortmund, Germany; Kerstin Jost, Department of Psychology, University of Marburg, Marburg, Germany, and Department of Psychology, RWTH Aachen University, Aachen, Germany; Andrea M. Philipp and Iring Koch, Department of Psychology, RWTH Aachen University.This article was supported by the Deutsche Forschungsgemeinschaft (DFG) in the context of the priority program "Executive Functions" (Grants Fa 211115-1,2; Ho 1301/8-1,2,3; Hu 432/8-1,2,3; KI 488/6-1,2,3; Ko 2045/4-1,2,3; and Ro 529/17-1,2,3). We thank Stephen Monsell for very helpful comments on earlier versions of the article.Correspondence concerning this article should be addressed to Andrea Kiesel, Department of Psychology, University of Wiirzburg, Rontgenring 11, 97070 Wiirzburg, Germany, or to Iring Koch, Lehrstuhl fur Psycholo!,>ie I, RWTH Aachen University, Jiigerstrasse 17-19,52056 Aachen, Germany. ...

Response selection in task shifting was explored using a go/no-go methodology. The no-go signal occurred unpredictably with stimulus onset so that all trials required task preparation but only go trials required response selection. Experiment 1 showed that shift costs were absent after no-go trials, indicating that response processes are crucial for shift costs. In Experiment 2, backward inhibition was absent after no-go trials. Experiments 3 and 4 demonstrated that response selection, rather than execution, causes backward inhibition. All 4 experiments showed effects of preparation time in go trials, suggesting that advance preparation must have also occurred in no-go trials. The authors concluded that inhibition of irrelevant task sets arises only at response selection and that residual shift costs reflect such persisting inhibition.Portions of this research were supported by German Research Foundation Grant KO 2045/4-1 to Iring Koch. We thank Richard Carlson, Ulrich Mayr, and Nachshon Meiran for valuable comments on an earlier version of this article. We also thank Andrea Barrera and Silvija Mikerevic for conducting part of the experiments and Heidi John and Natalie Sebanz for stylistic suggestions.

No abstract

No abstract