Author: Lucy Matson
Matson, Lucy, 2024 Stuck on disgust: Investigating disgust’s memorability, Flinders University, College of Education, Psychology and Social Work
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People remember disgust better (e.g., more frequently and accurately) than other negative and arousing emotions, like fear (termed disgust memory enhancement). However, the existing literature examining disgust memory enhancement focuses on voluntary recall and recognition in a laboratory setting. My thesis aimed to address gaps in the literature by examining whether disgust memory enhancement extends to various forms of episodic memory (particularly those relevant to traumatic experiences and Posttraumatic Stress Disorder; PTSD), across a combination of laboratory and real-world settings.
First, I examined disgust’s memorability in the context of intrusions (or, involuntary memories) in response to personal traumatic events (Chapter 3) and an analogue trauma (i.e., images; Chapter 4). I found that the extent to which people reported feeling disgust was associated with higher intrusion severity (i.e., intrusion persistence) and problematic intrusion characteristics (e.g., distress) to a comparable extent to feelings of fear (Chapter 3). Disgust reactions uniquely predicted intrusion symptoms (i.e., over-and-above fear). Participants also experienced a similar number of intrusions for disgust images (relative to fear images; Chapter 4), and disgust intrusions became more emotionally intense than fear intrusions over time. My findings emphasise disgust’s unique role in trauma-related intrusions and suggest disgust memory enhancement extends to intrusions in some ways (enhanced emotional intensity of these intrusions) but not others (intrusion frequency).
Second, I explored whether disgust memory enhancement extends to more accurate memory (Chapter 5). The existing memory recognition literature has found consistently low false memory rates for disgust and fear images, likely due to various methodological limitations. For example, in some of these studies the disgust (and fear) image lures matched the emotion category but not the specific content of previously seen (old) images (i.e., the lures were unrelated). I addressed this limitation by matching each disgust image lure’s content to an ‘old’ disgust image and did the same for the fear images: these lures were related. Participants experienced a similar rate of false memories for disgust and fear when lures were related, and fewer false memories for disgust than fear when lures were unrelated. Thus, disgust is not particularly susceptible to false remembering. Rather, consistent with prior research, participants had enhanced memory accuracy (i.e., higher correct recognition rates and better memory sensitivity) for disgust relative to fear.
Finally, I explored memory for feelings of disgust (Chapter 6), addressing an overarching limitation of past research, which focuses exclusively on memory for disgust content (e.g., stimuli, event details). Whilst participants’ disgust and fear reactions to a recent traumatic event similarly persisted in intensity over time (longitudinally), participants retrospectively remembered more persistent feelings of disgust than fear. Therefore, disgust memory enhancement extends to persistent feelings.
Taken together, my thesis extends a growing body of literature showing disgust is particularly ‘sticky’ in memory. Overall, my findings provide some support for disgust memory enhancement (relative to fear) and in other cases, suggest disgust is comparably memorable to fear. Theoretically, my findings fit with both dimensional and discrete accounts of emotion. Clinically, given disgust’s durability in memory following traumatic events, disgust should not be overlooked in cognitive models, diagnostic tools and treatments for PTSD.
Keywords: memory, disgust, emotion, fear, intrusions, trauma, PTSD, post traumatic stress disorder, clinical cognition
Subject: Psychology thesis
Thesis type: Doctor of Philosophy
Completed: 2024
School: College of Education, Psychology and Social Work
Supervisor: Professor Melanie Takarangi