Understanding Emotional Memory: Cognitive Factors A thesis submitted to The University of Manchester for the degree of Doctor of Philosophy in the Faculty of Medical and Human Sciences. 2015 Gemma Elizabeth Barnacle School of Psychological Sciences Table of Contents List of Figures ........................................................................................................................................................... 7 List of Tables ............................................................................................................................................................. 8 List of Abbreviations .............................................................................................................................................. 9 Abstract .................................................................................................................................................................... 11 Declaration.............................................................................................................................................................. 12 Copyright Statement ........................................................................................................................................... 13 Alternative Format Rationale .......................................................................................................................... 14 Acknowledgements ............................................................................................................................................. 15 The Author .............................................................................................................................................................. 16 1. General Introduction .................................................................................................................. 17 Overview ............................................................................................................................................................. 17 1.1. Definitions ................................................................................................................................................. 19 1.1.1. Emotion ............................................................................................................................................. 19 1.1.2. Memory ............................................................................................................................................. 21 1.1.3. Cognition and cognitive factors ............................................................................................... 22 1.2. How the modulation model explains the EEM effect: Consolidation................................. 25 1.3. Neuroimaging of the EEM effect ....................................................................................................... 29 1.3.1. Electroencephalography: The P300 and Late Positive Potential (LPP) .................. 30 1.3.2. Functional MRI ............................................................................................................................... 32 1.4. The EEM effect before consolidation: Cognitive effects. ......................................................... 34 1.4.1. Attention ........................................................................................................................................... 35 1.4.2. Semantic relatedness ................................................................................................................... 41 1.4.3. Distinctiveness processing ........................................................................................................ 45 1.5. Conclusion ................................................................................................................................................. 51 2. General Methodology ................................................................................................................. 53 2.1. Behavioural investigation of the emotional enhancement of memory ............................. 53 2.1.1. Paradigm overview ........................................................................................................................ 53 2.1.2. Using free recall to test memory .............................................................................................. 54 2.1.3. The subsequent memory paradigm and difference due to memory (Dm) ............. 56 2.2. Neuroscientific investigation of the emotional enhancement of memory ....................... 57 2.2.1. Electroencephalography and event-related potentials................................................... 57 2.2.2. Functional Magnetic Resonance Imaging ............................................................................. 58 2.2.3. Statistical Parametric Mapping................................................................................................. 59 2 2.3. Neuroimaging model specification and evaluation ................................................................... 60 3. Development of the Semantically Related Emotional and Neutral Stimuli Sets (SeRENS) .................................................................................................................................................. 64 Abstract ............................................................................................................................................................... 64 3.1. Introduction .............................................................................................................................................. 65 3.1.1. Semantic relatedness as a confound to empirical psychological investigation..... 66 3.1.2. Visual complexity as a confound to empirical psychological investigation ............ 68 3.2. Method ......................................................................................................................................................... 69 3.2.1. Participants ....................................................................................................................................... 69 3.2.2. Materials ............................................................................................................................................ 70 3.2.3. Procedure .......................................................................................................................................... 73 3.2.4. Analysis .............................................................................................................................................. 75 3.3. Results ......................................................................................................................................................... 80 3.3.1. Originals ............................................................................................................................................. 80 3.3.2. Duplicates .......................................................................................................................................... 80 3.3.3. Correlations ...................................................................................................................................... 81 3.4. Discussion .................................................................................................................................................. 82 3.4.1. Correlation of Arousal and Valence ........................................................................................ 83 3.4.2. Methodological evaluation ......................................................................................................... 84 3.4.3. Flexibility of stimuli selection for future studies ............................................................... 86 3.5. Conclusion .................................................................................................................................................. 87 4. Using EEG to investigate the contribution of distinctiveness processing to the immediate emotional enhancement of memory. ...................................................................... 89 Abstract ............................................................................................................................................................... 89 4.1. Introduction .............................................................................................................................................. 90 4.1.1. The influence of cognition on the EEM effect: Distinctiveness processing and semantic relatedness ..................................................................................................................................... 90 4.1.2. Electrophysiology of memory and the EEM ....................................................................... 93 4.1.3. Current design and hypotheses ............................................................................................... 96 4.2. Method ........................................................................................................................................................ 97 4.2.1. Participants ...................................................................................................................................... 97 4.2.2. Materials and equipment ..........................................................................................................