Examining the Nature of the Relationship Between Working Memory and Attention

ii DEDICATION This is dedicated to my family. Thank you for your enduring love and support through this journey, I could not have done it without all of you. iii ACKNOWLEDGEMENTS I would like to thank the members of my dissertation committee, Raja Parasuraman, Pamela Greenwood, and Craig McDonald. They spent countless hours providing me with helpful insights and guidance throughout the dissertation process. Their aid was truly invaluable. Others have also made significant contributions during my tenure as a doctoral student at George Mason University. James Thompson served on my comprehensive exam committee; I am grateful for his willingness to allocate his time to that process. Additionally, Karl Fryxell and Ming-Kuan Lin have provided me with knowledge and opportunities in an area outside of my specific field of study. Their patience allowed me to explore an area of interest to me that I would otherwise not have had an opportunity to pursue. Additionally, I would like to thank the research assistants that put so much effort into studies over the years—particularly Simon Stöckl and Justine Santos. Finally, I would like to thank my friends and classmates. They are inspiring people who were always willing to help me achieve my goals. Working memory (WM) and visuospatial attention (VA) are both cognitive constructs that are related to the processing of relevant information. While these processes are capable of functioning independently, there is significant evidence suggesting a relationship between the two. However, the exact nature of this relationship is not well understood, and no testable hypotheses have been advanced. In this dissertation, three experiments were conducted in an effort to uncover the nature of the relationship between WM and VA. It was hypothesized that when WM and VA are simultaneously deployed, a new process is formed (an integrated view). Based on this hypothesis, it was predicted that this new process would operate using the shared resources of WM and VA. This hypothesis was compared against the parallel view, which stated that WM and VA are separate processes that simply interact. The parallel view would not predict processing resources to be shared between WM and VA. The three experiments were designed to provide converging evidence to support one of these views by targeting different aspects of WM and VA and using various measurement techniques. x Results showed support for the integrated view. Specifically, it was demonstrated that manipulations in either WM or VA …