An investigation of our ability to control unwanted autobiographical memories of past morally relevant actions: EEG and behavioural evidence

We are often faced with reminders of unpleasant memories from our past that triggers a discomforted state of being. Attempts to avoid such reminders would be futile. Fortunately, a large body of research indicates that the unwanted memories and emotions elicited by these reminders can be controlled to improve our mental state. However, our understanding of this memory control is based on simpler memories such as words or pictures. So, the present thesis aimed to explore our ability to control memories of complex autobiographical memories, and its consequences on memory and emotion. Memories of past morally wrong actions were specifically observed as they are theorised to be particular motivators to engage control processes. In the first experiment (Chapter 3), evidence from real-time behavioural, ERP, and EEG oscillation measures indicated that autobiographical memories can be successfully avoided using direct suppression. Moreover, morally wrong memories were rated as more difficult to suppress than morally right memories. Importantly, repeated attempts at memory control improved the ability to reduce unwanted intrusions of memory contents (Chapter 3), and ameliorated the immediate negative emotions associated with morally wrong memories (Chapter 5). Both strategies of substituting negative thoughts with positive imagery, and upward counterfactual thinking, provided a distinct advantage over direct suppression for regulation of immediate emotions. The experiment reported in Chapter 4 found that suppression was not effective at beating the EEG-based forensic concealed-information test for either immoral and personal, or lab-created, autobiographical memories. The thesis thus provides new evidence that suppression may not be effective at avoiding incrimination from this forensic test for real-world emotional autobiographical memories. Overall, memory control can be useful for reducing intrusive thoughts and negative emotions associated with unpleasant autobiographical memories of past immoral actions. The thesis has implications for theories of memory control, emotion regulation and forensic practice.