Overestimating the intensity of negative feelings in autobiographical memory: evidence from the 9/11 attack and COVID-19 pandemic.

When recalling autobiographical events, people not only retrieve event details but also the feelings they experienced. The current study examined whether people are able to consistently recall the intensity of past feelings associated with two consequential and negatively valenced events, i.e. the 9/11 attack (N = 769) and the COVID-19 pandemic (N = 726). By comparing experienced and recalled intensities of negative feelings, we discovered that people systematically recall a higher intensity of negative feelings than initially reported - overestimating the intensity of past negative emotional experiences. The COVID-19 dataset also revealed that individuals who experienced greater improvement in emotional well-being displayed smaller biases in recalling their feelings. Across both datasets, the intensity of remembered feelings was correlated with initial feelings and current feelings, but the impact of the current feelings was stronger in the COVID-19 dataset than in the 9/11 dataset. Our results demonstrate that when recalling negative autobiographical events, people tend to overestimate the intensity of prior negative emotional experiences with their degree of bias influenced by current feelings and well-being.

Emotion language use in narratives of the 9/11 attacks predicts long-term memory.

Despite considerable cognitive neuroscience research demonstrating that emotions can influence the encoding and consolidation of memory, research has failed to demonstrate a relationship between self-reported ratings of emotions collected soon after a traumatic event and memory for the event over time. This secondary analysis of data from a multisite longitudinal study of memories of the September 11, 2001 terrorist attacks, asked the question of whether emotional language use could predict memory over time. In the 2 weeks following the 9/11 attacks, participants (N = 691; Mage = 36.8; 72% identifying as male; 76% identifying as white) wrote narratives about how they learned of the attacks and the impact of the attacks on them. Language features of these narratives were extracted using the Linguistic Inquiry Word Count program and used to predict three types of memory: (a) event memory accuracy, (b) flashbulb memory consistency, and (c) emotion memory consistency. These outcomes were assessed at the time of writing, 1, 3, and 10 years after the 9/11 attacks. Results of linear mixed-effects models indicate that greater use of negative emotion words in narratives predicts better event memory accuracy 3 and 10 years after the attacks and worse flashbulb memory consistency 10 years after the attacks. However, emotion word use does not predict emotion memory consistency across time. We also examine whether other exploratory linguistic predictors are associated with memory over time. These findings suggest that written language may serve as a potential early indicator of memory over time. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Human threat learning is associated with gut microbiota composition.

The ability to learn about threat and safety is critical for survival. Studies in rodent models have shown that the gut microbiota can modulate such behaviors. In humans, evidence showing an association with threat or extinction learning is lacking. Here, we tested whether individual variability in threat and extinction learning was related to gut microbiota composition in healthy adults. We found that threat, but not extinction learning, varies with individuals' microbiome composition. Our results provide evidence that the gut microbiota is associated with excitatory threat learning across species.

Implicit but not explicit extinction to threat-conditioned stimulus prevents spontaneous recovery of threat-potentiated startle responses in humans.

INTRODUCTION: It has long been posited that threat learning operates and forms under an affective and a cognitive learning system that is supported by different brain circuits. A primary drawback in exposure-based therapies is the high rate of relapse that occurs when higher order areas fail to inhibit responses driven by the defensive circuit. It has been shown that implicit exposure of fearful stimuli leads to a long-lasting reduction in avoidance behavior in patients with phobia. Despite the potential benefits of this approach in the treatment of phobias and posttraumatic stress disorder, implicit extinction is still underinvestigated. METHODS: Two groups of healthy participants were threat conditioned. The following day, extinction training was conducted using a stereoscope. One group of participants was explicitly exposed with the threat-conditioned image, while the other group was implicitly exposed using a continuous flash suppression (CFS) technique. On the third day, we tested the spontaneous recovery of defensive responses using explicit presentations of the images. RESULTS: On the third day, we found that only the implicit extinction group showed reduced spontaneous recovery of defensive responses to the threat-conditioned stimulus, measured by threat-potentiated startle responses but not by the electrodermal activity. CONCLUSION: Our results suggest that implicit extinction using CFS might facilitate the modulation of the affective component of fearful memories, attenuating its expression after 24 hr. The limitations of the CFS technique using threatful stimuli urge the development of new strategies to improve implicit presentations and circumvent such limitations. Our study encourages further investigations of implicit extinction as a potential therapeutic target to further advance exposure-based psychotherapies.

Targeted Memory Reactivation during Sleep Adaptively Promotes the Strengthening or Weakening of Overlapping Memories.

System memory consolidation is conceptualized as an active process whereby newly encoded memory representations are strengthened through selective memory reactivation during sleep. However, our learning experience is highly overlapping in content (i.e., shares common elements), and memories of these events are organized in an intricate network of overlapping associated events. It remains to be explored whether and how selective memory reactivation during sleep has an impact on these overlapping memories acquired during awake time. Here, we test in a group of adult women and men the prediction that selective memory reactivation during sleep entails the reactivation of associated events and that this may lead the brain to adaptively regulate whether these associated memories are strengthened or pruned from memory networks on the basis of their relative associative strength with the shared element. Our findings demonstrate the existence of efficient regulatory neural mechanisms governing how complex memory networks are shaped during sleep as a function of their associative memory strength.SIGNIFICANCE STATEMENT Numerous studies have demonstrated that system memory consolidation is an active, selective, and sleep-dependent process in which only subsets of new memories become stabilized through their reactivation. However, the learning experience is highly overlapping in content and thus events are encoded in an intricate network of related memories. It remains to be explored whether and how memory reactivation has an impact on overlapping memories acquired during awake time. Here, we show that sleep memory reactivation promotes strengthening and weakening of overlapping memories based on their associative memory strength. These results suggest the existence of an efficient regulatory neural mechanism that avoids the formation of cluttered memory representation of multiple events and promotes stabilization of complex memory networks.

Motivated encoding selectively promotes memory for future inconsequential semantically-related events.

Neurobiological models of long-term memory explain how memory for inconsequential events fades, unless these happen before or after other relevant (i.e., rewarding or aversive) or novel events. Recently, it has been shown in humans that retrospective and prospective memories are selectively enhanced if semantically related events are paired with aversive stimuli. However, it remains unclear whether motivating stimuli, as opposed to aversive, have the same effect in humans. Here, participants performed a three phase incidental encoding task where one semantic category was rewarded during the second phase. A memory test 24h after, but not immediately after encoding, revealed that memory for inconsequential items was selectively enhanced only if items from the same category had been previously, but not subsequently, paired with rewards. This result suggests that prospective memory enhancement of reward-related information requires, like previously reported for aversive memories, of a period of memory consolidation. The current findings provide the first empirical evidence in humans that the effects of motivated encoding are selectively and prospectively prolonged over time.

Updating fearful memories with extinction training during reconsolidation: a human study using auditory aversive stimuli.

Learning to fear danger in the environment is essential to survival, but dysregulation of the fear system is at the core of many anxiety disorders. As a consequence, a great interest has emerged in developing strategies for suppressing fear memories in maladaptive cases. Recent research has focused in the process of reconsolidation where memories become labile after being retrieved. In a behavioral manipulation, Schiller et al., (2010) reported that extinction training, administrated during memory reconsolidation, could erase fear responses. The implications of this study are crucial for the possible treatment of anxiety disorders without the administration of drugs. However, attempts to replicate this effect by other groups have been so far unsuccessful. We sought out to reproduce Schiller et al., (2010) findings in a different fear conditioning paradigm based on auditory aversive stimuli instead of electric shock. Following a within-subject design, participants were conditioned to two different sounds and skin conductance response (SCR) was recorded as a measure of fear. Our results demonstrated that only the conditioned stimulus that was reminded 10 minutes before extinction training did not reinstate a fear response after a reminder trial consisting of the presentation of the unconditioned stimuli. For the first time, we replicated Schiller et al., (2010) behavioral manipulation and extended it to an auditory fear conditioning paradigm.

Female degus (Octodon degus) monitor their environment while foraging socially.

Vigilance or scanning involves interruptions in foraging behavior when individuals lift their heads and conduct visual monitoring of the environment. Theoretical considerations assume that foraging with the "head down", and scanning ("head up") are mutually exclusive activities, such that foraging precludes vigilance. We tested this generalization in a socially foraging, small mammal model, the diurnal Chilean degu (Octodon degus). We studied spontaneous bouts of scanning of captive degus when foraging in pairs of female sibs and non-sibs. We examined the extent to which foraging (head down postures) and scanning (head up postures) were mutually exclusive in subjects exposed to none, partial, and complete lateral visual obstruction of their partners. In addition, we monitored the orientation of their bodies to examine the target of attention while foraging and scanning. Lastly, we examined the temporal occurrence of scanning events to assess the extent of scanning coordination, and whether this coordination is kin-biased. Visual obstruction had a significant influence on degu vigilance. Focal degus increased their quadrupedal and semi-erect scanning when foraging under a partially obstructed view of their partners. Degus oriented their bodies toward partners when foraging and scanning. Despite this, degus did not coordinate scanning bouts; instead, they scanned independently from one another. Relatedness among cage mates did not influence any aspect of degu behavior. Contrary to theoretical expectations, these results indicate that foraging and vigilance are not mutually exclusive, and that kinship per se does not influence scanning behavior and coordination.