Selected Publications

Gaslighting is a form of psychological manipulation where victims are led to doubt their own thoughts, perception of reality, or memories. Despite thegrowing popularity of the term and purported harmful implications, empirical efforts to operationalize and define gaslighting remain sparse. This study aimed to define common features and themes of self-reported gaslighting experiences. Young adults (N=250) completed several questionnaires and open-ended prompts relating to gaslighting experiences. Using a variety of natural language processing techniques, we explore the gaslighting construct using a data-driven approach from the perspective of self-reported targets of gaslighting.These data confirmthat gaslighting is a type of interpersonal manipulation aimed at making a person feel 'crazy' or doubt their memories. Romantic partners were reported to be the most common perpetrators of gaslighting, and both beneficial (e.g., awareness of manipulative people) and detrimental (e.g., self-doubt) consequences of experiencing gaslighting appear to be long-lasting. Additionally, we found that more severe, frequent, and long-lastinggaslighting experiences are associated with broader subjective memory deficits, even extending to other memories outside of the gaslighting eventitself. This study highlights potential cognitive and psychological impacts of gaslighting, and underscores the need for further empirical research and informed clinical strategies.

Memories are pliable and can be biased by post-encoding information. In targeted memory reactivation (TMR) studies, participants encode information then sleep, during which time sounds or scents that were previously associated with the encoded images are re-presented in an effort to trigger reactivation of the associated memory traces. Upon subsequent testing, memory for reactivated items is often enhanced. Is sleep essential for this process? The literature on awake TMR is small and findings are mixed. Here, we asked English-speaking adults to learn Japanese vocabulary words. During a subsequent active rest phase, participants played Tetris while sound cues associated with the vocabulary words were presented. Results showed that when memories were reactivated, they were either disrupted (Experiment 1) or unaffected (Experiments 2, 3). These findings indicate that awake TMR is not beneficial, and may actually impair subsequent memory. These findings have important implications for research on memory consolidation and reactivation.

Threatening events influence memory systems in complex ways. While it was once believed that emotion enhanced all aspects of memory, recent evidence suggests that it improves recall of emotional central features, but not neutral peripheral details (Payne & Kensinger, 2011). Other studies show that emotion can enhance context, retroactively benefiting related neutral events over time (Dunsmoor et al., 2015). Notably, both effects emerge after sleep, indicating a role for memory consolidation. Recently, Cowan et al. (2021) proposed that consolidation not only strengthens salient information but also adaptively transforms memories via semanticization and integration. In this dissertation, we adopt this adaptive memory framework to investigate behavioral and neural markers of threat memory transformation. First, using free recall changes over a week as a behavioral measure of memory transformation, we show that higher subjective arousal predicts greater semanticization, with fewer episodic details retained over time. Next, functional connectivity analyses reveal a division between anterior and posterior hippocampus: the posterior hippocampus, in conjunction with the basolateral amygdala and sensory cortex during encoding, is linked to less memory semanticization, while the anterior hippocampus, coupled with the lateral occipital cortex and precuneus during post-encoding, predicts greater semanticization. Moreover, representational similarity analyses reveal that long-term memory reinstatement is strongest in the precuneus, resembling early encoding patterns, with both hippocampal regions shifting over time towards gist representations, albeit with varying granularity. Finally, we report a negative relationship between neural reinstatement in the lateral occipital cortex and memory semanticization, suggesting that detailed cortical representations help preserve event details over time. These findings support the adaptive memory model (Cowan et al., 2021), emphasizing the dynamic roles of the hippocampus, amygdala and cortex in threat memory transformation.

Systems consolidation theories posit that consolidation occurs primarily through a coordinated communication between hippocampus and neocortex (Moscovitch, M., & Gilboa, A., 2021; Kumaran, D., Hassabis, D., & McClelland, J. L., 2016; McClelland, J. L., & O’Reilly, R. C., 1995). Recent sleep studies in rodents have shown that hippocampus and visual cortex replay the same information at temporal proximity (“co-replay”; Lansink,C. S. et al., 2009; Peyrache, A. et al., 2009; Wierzynski,C.M. et al., 2009; Ji, D., & Wilson, 2007). We developed a novel repetition time (TR)-based co-reactivation analysis method to study hippocampal–cortical co-replays in humans using fMRI. Thirty-six young adults completed an image (face or scene) and location paired associate encoding task in the scanner, which were preceded and followed by resting state scans. We identified post-encoding rest TRs (± 1) that showed neural reactivation of each image–location trials in both hippocampus (HPC) and category-selective cortex (fusiform face area [FFA]). This allowed us to characterize temporally proximal coordinated reactivations (“co-reactivations”)between HPC and FFA. Moreover, we found that increased HPC–FFA co-reactivations were associated with incorrectly recognized trials after a 1-week delay ( p = .004). Finally, we found that these HPC–FFA co-reactivations were also associated with trials that were initially correctly recognized immediately after encoding but were later forgotten in 1-day ( p = .043) and 1week delay period ( p = .031). We discuss these results from a trace transformation perspective (Sekeres, M. J., Winocur, G., & Moscovitch, 2018; Winocur, G., & Moscovitch, 2011) and speculate that HPC–FFA co-reactivations may be integrating related events, at the expense of disrupting event-specific details, hence leading to forgetting.

Hippocampal impairments are reliably associated with post-traumatic stress disorder (PTSD); however, little research has characterized how increased threat sensitivity may interact with arousal responses to alter hippocampal reactivity, and further how these interactions relate to the sequelae of trauma-related symptoms. In a sample of individuals recently exposed to trauma (N = 116, 76 female), we found that PTSD symptoms at 2 weeks were associated with decreased hippocampal responses to threat as assessed with fMRI. Further, the relationship between hippocampal threat sensitivity and PTSD symptomology only emerged in individuals who showed transient, high threat-related arousal, as assayed by an independently collected measure of fear potentiated startle. Collectively, our finding suggests that development of PTSD is associated with threat-related decreases in hippocampal function because of increases in fear-potentiated arousal.