Investigations on the Shielding Function of Task Sets and its Underlying Mechanism

............................................................................................................. 8 I. Theoretical Background .................................................................... 9 Cognitive Control ............................................................................................................ 10 An Introduction to Cognitive Control................................................................... 10 Cognitive Control and the Prefrontal Cortex ....................................................... 11 The Representation of Task Sets .......................................................................... 13 The Stability and Flexibility of Behavior ............................................................... 14 Task Switching ................................................................................................................ 16 The History of Task Switching .............................................................................. 16 Rediscovery of the Task Switching Paradigm ....................................................... 20 Typical Effects in the Task Switching Paradigm ................................................... 24 Task switching: A summary .................................................................................. 32 The Shielding Function of Task Sets ............................................................................... 32 Task Sets vs. Stimulus-Response-Mappings ......................................................... 33 Definitions ............................................................................................................ 37 First Findings on the Shielding Function .............................................................. 38 Relaxation of the Shielding Function ................................................................... 44 Scope of the Present Work .................................................................................. 45 II. The Shielding Function of Task Sets in the Presence of Task-Related Distracters ................................................................. 48 Introduction ................................................................................................................... 49 Experiment 1 .................................................................................................................. 52 Method ................................................................................................................ 52 Results .................................................................................................................. 55 Discussion............................................................................................................. 56 Experiment 2 .................................................................................................................. 58 Method ................................................................................................................ 58 Results .................................................................................................................. 61 Discussion............................................................................................................. 62 Experiment 3 .................................................................................................................. 64 Method ................................................................................................................ 64 Results .................................................................................................................. 65 Discussion............................................................................................................. 66 Experiment 4 .................................................................................................................. 67 Method ................................................................................................................ 67 Results .................................................................................................................. 67 Discussion............................................................................................................. 68 Conclusions .................................................................................................................... 68 III. Shielding in the Context of Random Task Switching ....................... 72 Introduction ................................................................................................................... 73 Experiment 5 .................................................................................................................. 77 Method ................................................................................................................ 77 Results .................................................................................................................. 80 Discussion............................................................................................................. 83 Experiment 6 .................................................................................................................. 85 Method ................................................................................................................ 86 Results .................................................................................................................. 88 Discussion............................................................................................................. 89 Conclusions .................................................................................................................... 90 IV. Shielding in the Context of Predictable Task Switching ................... 94 Introduction ................................................................................................................... 95 Experiment 7 .................................................................................................................. 97 Method ................................................................................................................ 97 Results .................................................................................................................. 98 Discussion........................................................................................................... 101 V. General Discussion ........................................................................ 104 Summary of the Current Findings ................................................................................ 105 Shielding and task-related distracters .......................................................................... 108 Shielding in a switching context ................................................................................... 109 The mechanism underlying the shielding function ................................................. 112 Implications of the shielding function .......................................................................... 117 Future Directions .......................................................................................................... 119 References ..................................................................................................... 122 Parts of the present thesis are published as: Reisenauer, R. & Dreisbach, G. (2013). The impact of task rules on distracter processing: automatic categorization of irrelevant stimuli. Psychological Research, 77, 128-138. Reisenauer, R. & Dreisbach, G. (2014). The shielding function of task sets in the context of task switching. Quarterly Journal of Experimental Psychology, 67, 358-376.