THE ROLE OF WORKING MEMORY CAPACITY IN FALSE MEMORY A Thesis Presented to the faculty of the Department of Psychology California State University, Sacramento Submitted in partial satisfaction of the requirements for the degree of MASTER OF ARTS in Psychology by Lilian Edith Cabrera SUMMER 2016 © 2016 Lilian Edith Cabrera ALL RIGHTS RESERVED ii THE ROLE OF WORKING MEMORY CAPACITY IN FALSE MEMORY A Thesis by Lilian Edith Cabrera Approved by: __________________________________, Committee Chair Jianjian Qin, Ph.D. __________________________________, Second Reader Lawrence S. Meyers, Ph.D. __________________________________, Third Reader Jeffrey Calton, Ph.D. ____________________________ Date iii Student: Lilian Edith Cabrera I certify that this student has met the requirements for format contained in the University format manual, and that this thesis is suitable for shelving in the Library and credit is to be awarded for the thesis. __________________________, Graduate Coordinator ___________________ Lisa M. Bohon, Ph.D. Date Department of Psychology iv Abstract of THE ROLE OF WORKING MEMORY CAPACITY IN FALSE MEMORY by Lilian Edith Cabrera The present study examined the effect of working memory capacity in false memory elicited by the DRM paradigm in two experiments (Experiment 1: N = 31, 80.6% female, age M = 21.29 years, SD = 4.26; Experiment 2: N = 29, 72.4% female, age M = 20.28 years, SD = 3.02). A concurrent digit load task was introduced to reduce available working memory capacity for the DRM task. The results of Experiment 1 revealed that false recall of critical lures was marginally higher when participants had a concurrent digit load task. While the initial increase in the digit load increased false recognition of critical lures, a further increase in the digit load reduced false recognition. In Experiment 2, participants were forewarned about the tendency of associative lists to elicit false memory of critical lures. Results from Experiment 2 demonstrated that while the concurrent digit load task did not affect false memory, warning instructions significantly reduced false recognition of critical lures. _______________________, Committee Chair Jianjian Qin, Ph.D. _______________________ Date v ACKNOWLEDGEMENTS First, I would like to express my sincerest gratitude to my graduate advisor, Dr. Jianjian Qin, for the immeasurable amount of support, guidance, and immense knowledge that he provided throughout the completion of my thesis. His guidance throughout my thesis research and graduate education has been pivotal to my growth as a student. I would also like to thank my committee members, Dr. Lawrence Meyers and Dr. Jeff Calton for their support in completing my thesis. Finally, I would like to thank my mother, father, and sisters, for their unconditional love, support, and encouragement. They have been a great source of motivation to continue my academic journey. I would also like to acknowledge my best friend and partner in life, Joshua Haro, who has been an invaluable source of support and encouragement during this significant chapter in my life. vi TABLE OF CONTENTS Page Acknowledgements ............................................................................................................ vi List of Tables ..................................................................................................................... ix List of Figures .................................................................................................................... xi Chapter 1. INTRODUCTION ........................................................................................................ 1 False Memory Research .......................................................................................... 3 Proposed Mechanisms for False Memory ............................................................. 12 The Role of Working Memory Capacity in False Memory .................................. 18 The Present Study ................................................................................................. 23 Hypotheses ............................................................................................................ 25 2. EXPERIMENT ONE .................................................................................................. 27 Method .................................................................................................................. 27 Materials ............................................................................................................... 28 Procedure .............................................................................................................. 30 Results ................................................................................................................... 32 Discussion ............................................................................................................. 45 3. EXPERIMENT TWO ................................................................................................. 48 Method .................................................................................................................. 48 Results ................................................................................................................... 49 Discussion ............................................................................................................. 62 vii 4. GENERAL DISCUSSION ......................................................................................... 65 Appendix A. DRM Word Lists ....................................................................................... 73 Appendix B. Participant Information Questionnaire ...................................................... 76 Appendix C. Inventory of Memory Experience ............................................................. 77 Appendix D. Warning Instructions ................................................................................. 83 References ......................................................................................................................... 84 viii LIST OF TABLES Tables Page 1. The Effect of Concurrent Digit Load on Recall Performance .............................. 36 2. The Effect of Concurrent Digit Load on Recognition Memory ........................... 36 3. The Effects of Concurrent Digit Load and WMC on False Alarm Rate for Critical Lures ........................................................................................................ 38 4. The Effect of Concurrent Digit Load on Sensitivity and Response Bias ............. 40 5. The Effects of Concurrent Digit Load and Word Type on Response Time (ms) . 42 6. Correlations between Memory Performance and Measures of Individual Differences ............................................................................................................ 43 7. Correlations between SDT Indices and Measures of Individual Differences ....... 45 8. The Effect of Concurrent Digit Load on Recall Performance .............................. 51 9. The Effects of Concurrent Digit Load, Warning Instructions, and WMC on False Recall of Critical Lures ............................................................................... 53 10. The Effect of Concurrent Digit Load on Recognition Memory ........................... 54 11. The Effects of Concurrent Digit Load, Warning Instructions, and WMC on False Alarm Rate for Critical Lures ...................................................................... 56 12. The Effect of Concurrent Digit Load on Sensitivity and Response Bias ............. 58 13. The Effects of Concurrent Digit Load and Word Type on Response Time (ms) . 59 14. Correlations between Memory Performance and Measures of Individual Differences ............................................................................................................ 60 ix 15. Correlations between SDT Indices and Measures of Individual Differences ....... 62 x LIST OF FIGURES Figure Page 1. Flow chart of the study procedure.. ...................................................................... 31 xi 1 Chapter 1 INTRODUCTION Memory plays a crucial role in numerous aspects of everyday life. Our memory provides us with the ability to remember a range of information from day-to-day tasks to life events, allowing us to create a history of events that occur throughout our lifetime. Although we can often trust the accuracy of our memory, memory can also be flawed. Two general ways that memory can fail include failing to remember something (omission memory error), or remembering incorrectly (commission memory error) (Roediger & McDermott, 2000; Schacter, 2001). In the past few decades, a substantial amount of research has emerged examining false memory, a memory of an event that never occurred but that an individual mistakenly identifies as an event that happened (Lampinen, Neuschatz, & Payne, 1997). To understand the occurrence of false memory, researchers have devised several procedures to elicit false memory. The most commonly employed procedure is the Deese-Roediger-McDermott paradigm (DRM; Roediger & McDermott, 1995). The DRM paradigm has been adopted in a variety of domains, including neuroimaging, development, aging, and individual differences to examine the mechanisms underlying false memory and factors that influence false memory susceptibility. For example, previous research has demonstrated that older adults are at risk of experiencing lower levels of veridical memory and higher