Publications by authors named "Verfaellie M"

Article Synopsis
  • The study explores the biological differences linked to PTSD by examining DNA methylation changes in blood, suggesting they could indicate susceptibility or effects of trauma.
  • Conducted by the Psychiatric Genomics Consortium, the research included nearly 5,100 participants to identify specific genetic markers associated with PTSD.
  • Results showed 11 significant CpG sites related to PTSD, with some also showing correlations between blood and brain tissue methylation, highlighting their potential role in understanding PTSD biology.
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Using narratives to reflect on experiences, emotions, and thoughts is associated with better health, enhanced mood, and improved symptoms of posttraumatic stress disorder (PTSD). Prior research examining narrative characteristics thought to reflect cognitive styles associated with PTSD has focused on trauma narratives, but the characteristics of nontrauma narratives in relation to PTSD are not fully understood. We reviewed the PTSD literature examining linguistic characteristics of nontrauma narratives, focusing on affective content, personal pronouns, and cognitive processing words.

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Previous studies have found that face perception deficits do not fully account for the severity of face recognition deficits in developmental prosopagnosia (DP). Researchers have begun identifying deficient memory mechanisms such as impaired face recollection, but these findings require replication, and further characterization of additional memory deficits is necessary. Our goals were to replicate prior findings of face recollection impairment in DP and extend these findings to assess different types of face associative memory.

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Article Synopsis
  • Researchers aimed to create and validate Methylation Risk Scores (MRS) using machine learning to identify individuals at risk for PTSD based on genomic and trauma exposure data.
  • The study developed three models: eMRS (which combines trauma exposure and methylation data), MoRS (which relies only on methylation data), and MoRSAE (which adjusts MoRS for trauma exposure).
  • The eMRS model showed the best performance with a 92% accuracy, and all models were able to predict post-deployment PTSD significantly, suggesting that including trauma exposure improves risk assessment.
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Face recognition is a highly developed and specialised human ability, distinct from other cognitive abilities. Previous studies examining individual differences in face recognition have focused on face perception and specialised perceptual mechanisms such as holistic face processing. However, the contribution of specific face memory processes to face recognition ability remains unclear.

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Article Synopsis
  • The study investigates the link between post-traumatic stress disorder (PTSD) and differences in DNA methylation, a type of gene regulation, in blood samples from individuals diagnosed with PTSD compared to trauma-exposed controls.
  • Researchers conducted a large-scale analysis involving over 5,000 participants from various civilian and military studies, using standardized procedures for PTSD assessment and DNA methylation testing.
  • The results revealed 11 specific DNA methylation sites associated with PTSD, and found similarities in methylation patterns between blood and brain tissues, suggesting a biological basis for the condition.
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Background And Objectives: Despite documented alterations in future thinking in posttraumatic stress disorder (PTSD), our understanding of how individuals with PTSD make future-oriented decisions is limited. We tested the hypothesis that increased discounting in association with PTSD reflects failure to spontaneously envision future rewarding situations.

Methods: Thirty-seven trauma exposed war-zone veterans completed a standard temporal discounting task as well as a temporal discounting task accompanied by episodic future thinking cues.

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Posttraumatic stress disorder (PTSD) is a heterogeneous disorder, and symptom severity varies over time. Neurobiological factors that predict PTSD symptoms and their chronicity remain unclear. This study investigated whether the volume of the hippocampus and its subfields, particularly cornu ammonis (CA) 1, CA3, and dentate gyrus, are associated with current PTSD symptoms and whether they predict PTSD symptom changes over 2 years.

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Article Synopsis
  • Humans often place more value on potential losses than gains due to a phenomenon called temporal discounting sign effect, which ties into emotional reactions to awaiting outcomes.
  • A study compared decision-making in people with hippocampal amnesia, who struggle with episodic thinking, to healthy controls, examining the impact of anticipated emotions on their choices.
  • Results indicated that both groups showed a similar sign effect, with less discounting of losses than gains, suggesting that the sign effect isn't reliant on the hippocampus or episodic memory, but rather on semantic future thinking and broader cognitive processes.
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Background: Incorporating genomic data into risk prediction has become an increasingly useful approach for rapid identification of individuals most at risk for complex disorders such as PTSD. Our goal was to develop and validate Methylation Risk Scores (MRS) using machine learning to distinguish individuals who have PTSD from those who do not.

Methods: Elastic Net was used to develop three risk score models using a discovery dataset (n = 1226; 314 cases, 912 controls) comprised of 5 diverse cohorts with available blood-derived DNA methylation (DNAm) measured on the Illumina Epic BeadChip.

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Research on the role of the hippocampus in memory acquisition has generally focused on active learning. But to understand memory, it is at least as important to understand processes that happen offline, during both wake and sleep. In a study of patients with amnesia, we previously demonstrated that although a functional hippocampus is not necessary for the acquisition of procedural motor memory during training session, it is required for its offline consolidation during sleep.

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Using a future event fluency task, the current study sought to examine future event construction in PTSD and to identify clinical profiles associated with altered event construction. Thirty-eight trauma exposed war-zone veterans with (n=25) and without (n=13) PTSD generated within one minute as many positive and negative future events as possible in the near and distant future. The PTSD group generated fewer specific, but not generic, events than the no-PTSD group, a difference that was amplified for positive events as a result of comorbid depression.

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Emotional future thinking serves important functions related to goal pursuit and emotion regulation but has been scantly studied in posttraumatic stress disorder (PTSD). The current study sought to characterize emotional future thinking in PTSD and to identify clinical and neurocognitive profiles associated with potential alterations in the level of detail in narratives of imagined future events. Fifty-eight, trauma-exposed, war-zone veterans, who were classified into current PTSD, past PTSD, and no-PTSD groups, were asked to vividly imagine future events in response to positive and negative cue words occurring in the near and distant future.

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Article Synopsis
  • Temporal discounting (TD) refers to the tendency to value immediate rewards more highly than delayed ones, and the role of the hippocampus in this process is debated due to conflicting findings between animal and human studies.
  • While animals with hippocampal lesions show impaired TD, humans with similar lesions perform well on traditional intertemporal choice tasks where outcomes are hypothetical.
  • A study was conducted using amnesic participants with hippocampal lesions to measure their performance on experiential tasks involving real-time rewards, revealing that those with lesions struggled with immediate decision-making, indicating the hippocampus is important for TD when rewards are directly experienced rather than hypothetical.
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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.

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It is well established that the ventromedial prefrontal cortex (vmPFC) plays a critical role in memory consolidation and the retrieval of remote long-term memories. Recent evidence suggests that the vmPFC also supports rapid neocortical learning and consolidation over shorter timescales, particularly when novel events align with stored knowledge. One mechanism by which the vmPFC has been proposed to support this learning is by integrating congruent information into existing neocortical knowledge during memory encoding.

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Temporal information, including information about temporal order and duration, is a fundamental component of event sequence memory. While previous research has demonstrated that aging can have a detrimental effect on memory for temporal order, there has been limited insight into the effect of aging on memory for durations, particularly within the context of sequences. In the current study, neurologically healthy young and older participants were administered two temporal match-mismatch tasks: one in which they were instructed on each trial to compare the temporal order or duration information of stimulus sequences presented first in a study phase and then, after a short delay, in a test phase (event sequence task); and a second in which participants were required to compare single durations or sequences of durations across study and test phases of each trial (pinwheel task).

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Article Synopsis
  • This study explores the interaction between simple probabilistic reinforcement learning (RL) and observation-based learning (OL), highlighting the role of the hippocampus alongside the striatum in these processes.
  • A computational model was used to analyze neuroimaging data, revealing that OL and RL might not work independently but instead collaborate, especially in predicting and understanding discrepancies in expected and actual rewards.
  • Additionally, the study found that using OL more than RL could enhance error signaling in the anterior insula, suggesting a connection between the systems involved in monitoring learning errors.
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Autobiographical memory consists of distinct memory types varying from highly abstract to episodic. Self trait knowledge, which is considered one of the more abstract types of autobiographical memory, is thought to rely on regions of the autobiographical memory neural network implicated in schema representation, including the ventromedial prefrontal cortex, and critically, not the medial temporal lobes. The current case study introduces an individual who experienced bilateral posterior cerebral artery strokes resulting in extensive medial temporal lobe damage with sparing of the ventromedial prefrontal cortex.

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The volume of subcortical structures represents a reliable, quantitative, and objective phenotype that captures genetic effects, environmental effects such as trauma, and disease effects such as posttraumatic stress disorder (PTSD). Trauma and PTSD represent potent exposures that may interact with genetic markers to influence brain structure and function. Genetic variants, associated with subcortical volumes in two large normative discovery samples, were used to compute polygenic scores (PGS) for the volume of seven subcortical structures.

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Posttraumatic stress disorder (PTSD) is characterised by alterations in autobiographical memory for traumatic and non-traumatic events. Studies that focus on event construction - the ability to search for and identify a specific event - have documented overgeneral memory in PTSD. However, the quality of autobiographical memory also depends on the ability to elaborate on an event once constructed by providing additional details.

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Article Synopsis
  • The study examines how people value immediate rewards over future ones, a behavior called temporal discounting, specifically through real-time, experiential choices using artistic photographs as rewards.
  • A new task was created to evaluate these experiential decisions against traditional hypothetical scenarios, revealing that participants' choices in the two tasks were governed by distinct psychological mechanisms.
  • Results showed that while the experiential task triggered temporal discounting consistent with delays and rewards, anxiety levels influenced choice behavior differently in the two settings, suggesting differing cognitive processes at play.
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Theoretical accounts of moral decision making imply distinct ways in which episodic memory processes may contribute to judgments about moral dilemmas that entail high conflict between a harmful action and a greater good resulting from such action. Yet, studies examining the status of moral judgment in amnesic patients with medial temporal lobe (MTL) lesions have yielded inconsistent results. To examine whether and how episodic processes contribute to high conflict moral decisions, amnesic patients with MTL damage and control participants were asked to judge the moral acceptability of a harmful action across two conditions that differed in the framing of the moral question.

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