Publication Date


Document Type


First Advisor

Lilly, Michelle M.

Degree Name

Ph.D. (Doctor of Philosophy)

Legacy Department

Department of Psychology


Memory disorders; Psychic trauma; Episodic memory; Post-traumatic stress disorder


Trauma survivors who develop posttraumatic stress disorder (PTSD) often display symptoms of memory fragmentation such as an impaired ability to recall trauma memories. These observations are consistent with prominent theories of PTSD, which consider memory fragmentation as a central feature of PTSD. Correspondingly, most empirically-supported interventions for PTSD focus on addressing dysfunctional thoughts and behaviors and integrating fragmented memories of the event. More recently, this assumption has been challenged by research indicating that metamemory---one's subjective beliefs about their memory functioning and quality---may partially account for reported memory fragmentation among individuals with PTSD. Memory underconfidence, regardless of whether or not it is founded or wholly accurate, may lead to feelings of anxiety, especially in the process of recalling and making sense of one's trauma memory. Despite the intertwined nature of their relationship, the association between memory and metamemory has been understudied in the trauma literature. This dissertation investigated whether PTSD is a disorder of memory fragmentation, perceived memory fragmentation, or both by examining the association between memory and metamemory. A trauma analogue between-subjects experimental design was employed. Eighty four healthy participants were randomly assigned to receive either positive feedback or negative feedback after completing a standardized memory assessment. Despite the use of randomization, the manipulation groups systematically differed on both baseline memory ability and baseline memory confidence. Contrary to the first hypothesis, after controlling for the effect of baseline metamemory beliefs, the groups did not differ on their recall task performance, F(1,80) = .34, p = .56. The second hypothesis was partially supported, suggesting that both memory ability and subjective memory beliefs contribute to participants' subsequent performance on a verbal recall task. Controlling for significant covariate variables (baseline metamemory beliefs and metamemory group), memory ability negatively predicted objective memory fragmentation, β = - .02, t = -2.20, p = .03. Lastly, manipulating participants to believe their memory abilities are poor did not adversely impact their subjective memory fragmentation scores. Subjective memory fragmentation was predicted by baseline metamemory beliefs (β = .004, t = 2.86, p = .003) and memory ability (β = .001, p = .04), but not metamemory group (β = .007, p = .83). Further, all post-hoc analyses examining possible interaction effects between metamemory and memory fragmentation (objective and subjective) were non-significant. Overall, manipulating participants' memory confidence failed to produce anticipated outcomes. The effects of memory ability did not trump the effects of other important covariates in predicting objective memory fragmentation. Likewise, metamemory group failed to predict subjective memory fragmentation. Although the hypothesized role of low memory confidence in PTSD symptoms was not consistently supported in the current trauma analogue study, there were reservations regarding the criterion validity of various paradigms and measurements (i.e., trauma analogue, manipulation checks, and objective memory fragmentation). Most notably, the failed randomization may have led to reduced potency of the manipulation paradigm, and subsequently, reduced statistical power in detecting the treatment effect. To date, this study is the first known experimental study aimed at testing the hypothesized role of low memory confidence in PTSD directly using a memory confidence manipulation paradigm. The current findings reflect ongoing challenges in accurately quantifying memory impairments among trauma survivors in both research and clinical settings.


Advisors: Michelle M. Lilly.||Committee members: Joseph Magliano; Randy McCarthy; Holly Orcutt; Katja Wiemer; Kevin Wu.||Includes bibliographical references.


ix, 139 pages




Northern Illinois University

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