Metacognition as a Mediator for Posttraumatic Stress Symptoms Following Childhood Stressful Life Events: An Examination of the Construct Validity of the Metacognitions Questionnaire-Posttraumatic Stress Disorder.

Both cognitive and metacognitive theories implicate posttraumatic metacognition as an important factor in the maintenance of posttraumatic stress symptoms (PTSS) following stressful life events (SLEs). The Metacognitions Questionnaire-posttraumatic stress disorder (MCQ-PTSD; Wells, 2009) was previously developed to assess for metacognitions specific to SLEs and resulting PTSS. This study aimed to examine the construct validity of this measure in the context of childhood SLEs specifically. First, we confirmed the factor structure underlying the MCQ-PTSD in our sample. We then assessed whether the MCQ-PTSD would function as expected based on a theoretical model in which, controlling for posttraumatic cognitions, posttraumatic metacognitions were expected to mediate the relationship between childhood SLEs and PTSS. Using data from a racially diverse sample of undergraduate psychology students (N = 402; Agemean = 19.38 ± 1.81) at a large Midwestern university, the two-factor structure of the MCQ-PTSD was confirmed. Among participants who endorsed clinically significant experience of childhood SLEs (n = 203; Agemean = 19.49 ± 1.94), negative metacognitions mediated the relationships of emotional and sexual abuse with PTSS, when controlling for other posttraumatic cognitions. These relationships were not observed for positive metacognitions. These results are consistent with a metacognitive model for PTSD and suggest that the MCQ-PTSD may be a valid measure of posttraumatic metacognitions following childhood SLEs.

The Hippocampus Contributes to Temporal Discounting When Delays and Rewards Are Experienced in the Moment.

Temporal discounting (TD) represents the mental devaluation of rewards that are available after a delay. Whether the hippocampus is critical for TD remains unclear, with marked discrepancies between animal and human studies: although animals with discrete hippocampal lesions display impaired TD, human participants with similar lesions show intact performance on classic intertemporal choice tasks. A candidate explanation for this discrepancy is that delays and rewards are experienced in the moment in animal studies but tend to be hypothetical in human studies. We tested this hypothesis by examining the performance of amnesic participants with hippocampal lesions (one female, six males) on a novel experiential intertemporal choice task that used interesting photographs occluded by thick lines as rewards (Patt et al., 2021). Using a logistic function to model indifference points data, we compared performance to that on a classic intertemporal choice task with hypothetical outcomes. Participants with hippocampal lesions displayed impaired patterns of choices in the experiential task but not in the hypothetical task. Specifically, hippocampal lesions were associated with decreased amplitude of the delay-reward trade-off, with persistent choice of the delayed option despite delay increase. These results help explain previous discrepancies across animal and human studies, indicating that the hippocampus plays a critical role in temporal discounting when the outcomes of decisions are experienced in the moment, but not necessarily when they are hypothetical.SIGNIFICANCE STATEMENT Impaired temporal discounting (TD) has been related to maladaptive behaviors, including substance dependence and nonadherence to medical treatment. There is consensus that TD recruits the brain valuation network but whether the hippocampal memory system is additionally recruited remains unclear. This study examined TD in hippocampal amnesia, providing a unique opportunity to explore the role of the hippocampus in cognition. Whereas most human studies have used hypothetical outcomes, this study used a novel experiential task with real-time delays and rewards. Results demonstrated hippocampal involvement in the experiential task, but not in a classic hypothetical task administered for comparison. These findings elucidate previous discrepancies between animal and human TD studies. This reconciliation is critical as animals serve as models of human neurocognition.

Verbal recall in amnesia: Does scene construction matter?

The hippocampus plays a critical role in episodic memory and imagination. One theoretical model posits that the hippocampus is important for scene construction, namely, the ability to conjure and maintain a scene-based representation in one's mind. To test one idea put forth by this view, we examined whether amnesia is associated with more severe impairment in memory when the to-be-remembered content places high demands on scene construction. To do so, we examined free recall performance for abstract (i.e., low scene imagery) and concrete, high scene-imagery single words in seven amnesic patients with hippocampal lesions and concomitant scene-construction deficits, and compared their performance to demographically matched healthy controls. As expected, amnesic patients were severely impaired in their free recall performance; however, their impairment did not differ as a function of word type. That is, their impairment was equally severe for words that evoke high versus low scene imagery. These findings suggest that the role of the hippocampus in verbal memory extends to content that does not place high demands on scene construction. Theoretical implications of these findings are discussed.

Self-referential encoding does not benefit memory for prior remembering across changing contexts.

Changes in context across instances of memory retrieval have been shown to impair memory for acts of prior remembering. The present study examined how self-referential encoding influences memory for prior remembering that occurred with or without context change. At encoding, participants processed each target in cue-target word pairs in relation to themselves or another person. During an initial cued-recall test, targets were tested with either the studied cues or semantically related, but previously unseen cues. During a second cued-recall test, all targets were tested with the studied cues, and participants judged whether they remembered retrieving each target during the first test. Regardless of self/other-reference, semantic context change across the two tests impaired memory for prior remembering. Furthermore, the magnitude of this impairment was larger for strongly self-associated vs. other-associated targets. Our findings suggest that self-referential encoding does not benefit memory for prior remembering in the face of contextual change.

Temporal discounting when outcomes are experienced in the moment: Validation of a novel paradigm and comparison with a classic hypothetical intertemporal choice task.

When faced with intertemporal choices, people typically devalue rewards available in the future compared to rewards more immediately available, a phenomenon known as temporal discounting. Decisions involving intertemporal choices arise daily, with critical impact on health and financial wellbeing. Although many such decisions are "experiential" in that they involve delays and rewards that are experienced in real-time and can inform subsequent choices, most studies have focused on intertemporal choices with hypothetical outcomes (or outcomes delivered after all decisions are made). The present study focused on experiential intertemporal choices. First, a novel intertemporal choice task was developed and validated, using delays experienced in real time and artistic photographs as consumable perceptual rewards. Second, performance on the experiential task was compared to performance on a classic intertemporal choice task with hypothetical outcomes. Involvement of distinct processes across tasks was probed by examining differential relations to state and trait anxiety. A two-parameter logistic function framework was proposed to fit indifference point data. This approach accounts for individual variability not only in the delay at which an individual switches from choosing the delayed to more immediate option, but also in the slope of that switch. Fit results indicated that the experiential task elicited temporal discounting, with effective trade-off between delay and perceptual reward. Comparison with the hypothetical intertemporal choice task suggested distinct mechanisms: first, temporal discounting across the two tasks was not correlated; and second, state and trait anxiety both were associated with choice behavior in the experiential task, albeit in distinct ways, whereas neither was significantly associated with choice behavior in the hypothetical task. The engagement of different processes in the experiential compared to hypothetical task may align with neural evidence for the recruitment of the hippocampus in animal but not in classic human intertemporal choice studies.