Memory-Based Attentional Guidance: A Window to the Relationship between Working Memory and Attention by Emma Wu Dowd Department of Psychology & Neuroscience Duke University Date:_______________________ Approved: ___________________________ Tobias Egner, Supervisor ___________________________ Stephen R. Mitroff ___________________________ Scott A. Huettel ___________________________ Michael L. Platt Dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the Department of Psychology & Neuroscience in the Graduate School of Duke University i 2016 v ABSTRACT Memory-Based Attentional Guidance: A Window to the Relationship between Working Memory and Attention by Emma Wu Dowd Department of Psychology & Neuroscience Duke University Date:_______________________ Approved: ___________________________ Tobias Egner, Supervisor ___________________________ Stephen R. Mitroff ___________________________ Scott A. Huettel ___________________________ Michael L. Platt An abstract of a dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the Department of Psychology & Neuroscience in the Graduate School of Duke University i 2016 v Copyright by Emma Wu Dowd 2016 Abstract Attention, the cognitive means by which we prioritize the processing of a subset of information, is necessary for operating efficiently and effectively in the world. Thus, a critical theoretical question is how information is selected. In the visual domain, working memory (WM)—which refers to the short-term maintenance and manipulation of information that is no longer accessible by the senses—has been highlighted as an important determinant of what is selected by visual attention. Furthermore, although WM and attention have traditionally been conceived as separate cognitive constructs, an abundance of behavioral and neural evidence indicates that these two domains are in fact intertwined and overlapping. The aim of this dissertation is to better understand the nature of WM and attention, primarily through the phenomenon of memory-based attentional guidance, whereby the active maintenance of items in visual WM reliably biases the deployment of attention to memory-matching items in the visual environment. The research presented here employs a combination of behavioral, functional imaging, and computational modeling techniques that address: (1) WM guidance effects with respect to the traditional dichotomy of top-down versus bottom-up attentional control; (2) under what circumstances the contents of WM impact visual attention; and (3) the broader hypothesis of a predictive and competitive interaction between WM and attention. Collectively, these empirical findings reveal the importance of WM as a distinct factor in attentional control and support current models of multiple-state WM, which may have broader implications for how we select and maintain information. iv Dedication For my beloved Maisie. v Contents Abstract .............................................................................................................................. iv List of Tables ..................................................................................................................... xi List of Figures ................................................................................................................... xii Acknowledgements .......................................................................................................... xvi 1. General Introduction ....................................................................................................... 1 1.1 A Traditional Dichotomy of Attentional Selection ................................................. 3 1.2 Working Memory and Attention ............................................................................. 6 1.2.1 The Role of Attention in Working Memory ...................................................... 6 1.2.2 The Role of Working Memory in Attention ...................................................... 8 1.2.3 A Reconceptualization of Working Memory and Attention ............................ 10 1.3 Working Memory Guides Visual Attention .......................................................... 13 1.4 The Limits of Attentional Guidance by Working Memory .................................. 17 1.5 Aims of the Present Thesis ................................................................................... 21 2. Working Memory Guidance Overrides Bottom-Up Salience Cues .............................. 23 2.1 Introduction ........................................................................................................... 23 2.2 Current Goals ........................................................................................................ 26 2.3 General Method .................................................................................................... 28 2.3.1 Apparatus ......................................................................................................... 28 2.3.2 Stimuli .............................................................................................................. 28 2.3.3 Procedure ......................................................................................................... 29 2.3.4 Trial Conditions ............................................................................................... 31 vi 2.3.5 Data Analysis ................................................................................................... 32 2.4 Experiment 1A ...................................................................................................... 36 2.4.1 Results .............................................................................................................. 36 2.4.2 Discussion ........................................................................................................ 37 2.5 Experiment 1B ...................................................................................................... 39 2.5.1 Results .............................................................................................................. 39 2.5.2 Discussion ........................................................................................................ 40 2.6 Experiment 2 ......................................................................................................... 41 2.6.1 Verification of “Pop-Out”-Like Search ........................................................... 42 2.6.2 Results .............................................................................................................. 43 2.6.3 Discussion ........................................................................................................ 44 2.7 Experiment 3 ......................................................................................................... 45 2.7.1 Results .............................................................................................................. 46 2.7.2 Discussion ........................................................................................................ 46 2.8 General Discussion ............................................................................................... 47 2.8.1 Working Memory Guidance or Strategy? ........................................................ 49 2.8.2 Conclusion ....................................................................................................... 52 3. Top-Down Control Over Working Memory Guidance Operates Via Working Memory Accessibility ...................................................................................................................... 54 3.1 Introduction ........................................................................................................... 55 3.2 General Methods ................................................................................................... 61 3.2.1 Apparatus ......................................................................................................... 61 3.2.2 Procedure ......................................................................................................... 62 vii 3.2.3 Design .............................................................................................................. 64 3.2.4 Data Analysis ................................................................................................... 65 3.3 Experiment 1 ......................................................................................................... 68 3.3.1 Behavioral Results ........................................................................................... 69 3.3.2 Model Fitting and Comparison ........................................................................ 70 3.3.3 Discussion ........................................................................................................ 71 3.4 Experiment 2 ......................................................................................................... 73 3.4.1 Behavioral Results ........................................................................................... 74 3.4.2 Model Fitting and Comparison ........................................................................ 75 3.4.3 Discussion ........................................................................................................ 76 3.5 Comparison of Model Families ...........................................................................