Emotional Episodic Memory Research Articles

Psilocybin and 2C-B at Encoding Distort Episodic Familiarity

BackgroundAs research on psychedelics (hallucinogenic serotonin receptor 2A agonists) progresses, it is important to delineate the reliability of supposedly unique effects across this drug class. One such effect is how psychedelics impair the formation (i.e., encoding) of hippocampal-dependent recollections (retrieval of specific details) while potentially enhancing the encoding of cortical-dependent familiarity (a feeling of knowing that a stimulus has been previously experienced). MethodsIn a double-blind, placebo-controlled, within-participants study (N = 20), we tested the acute effects of 2 distinct psychedelics, psilocybin and 2C-B, on the encoding of emotional episodic memories. During acute drug effects, participants viewed negative, neutral, and positive pictures. The following day (while sober), participants completed 2 separate memory tests for these pictures. ResultsUsing computational models of memory confidence, we found trends for psilocybin and 2C-B at encoding to impair estimates of recollection that were supported by other measures/analyses. Surprisingly, psilocybin and 2C-B at encoding impaired estimates of familiarity, but these impairments were likely due to a misattribution of heightened familiarity, because both drugs at encoding selectively increased familiarity-based false alarms, especially for negative and positive stimuli. Psilocybin and 2C-B at encoding also tended to impair estimates of metamemory (understanding one’s own memory) for negative and neutral memories but enhanced estimates of metamemory for positive memories, although these effects were less reliable in additional analyses. ConclusionsDespite differences in their chemistry, pharmacology, and subjective effects, both psilocybin and 2C-B distorted episodic familiarity, suggesting a common neurocognitive mechanism across psychedelics that may drive other phenomena.

Context reexposure to bolster contextual dependency of emotional episodic memory

Contextual overgeneralization of emotional memory is a core aspect of anxiety disorders. Identifying methods to enhance contextual dependency of emotional memory is therefore of significant clinical interest. Animal research points to a promising approach: reexposure to the context in which fear is acquired reduces generalization to other contexts. However, the exact conditions for this effect are unknown, complicating translation to effective interventions. Most notably, exposure to a context that resembles—but is not identical to—the learning context may diminish contextual dependency of memory by integration of additional contextual cues. Here, we therefore assessed in a large-scale study (N = 180) whether context reexposure enhances contextual dependency of emotional episodic memory whereas exposure to a similar context impairs it. We also tested whether relatively strong memory retrieval during context (re)exposure amplifies these effects. We replicated prior research showing that correct recognition depends on context and contextual dependency is lower for emotional than neutral memories. However, exposure to the encoding context or a similar context did not affect contextual dependency of memory, and retrieval strength did not interact with such effects. Thorough insight into factors underlying the effects of context (re)exposure on contextual dependency seems key to eventually attain a memory recontextualization intervention.

One-week sleep hygiene education improves episodic memory in young but not in older adults during social isolation.

Memory formation is a dynamic process that comprises different phases, such as encoding, consolidation and retrieval. It could be altered by several factors such as sleep quality, anxiety, and depression levels. In the last years, due to COVID-19 pandemic, there was a reduction in sleep quality, an increase in anxiety and depressive symptoms as well as an impairment in emotional episodic memory encoding, especially in young adults. Taking into account the profound impact of sleep quality in daily life a series of rules has been developed that are conducive to consistently achieving good sleep, known as sleep hygiene education. These interventions have been shown to be effective in improving sleep quality and duration and reducing depressive and anxiety symptoms. Here we propose the implementation of a brief sleep hygiene education to improve sleep quality and memory performance as well as to diminish anxiety and depressive scores. For that, participants were divided into two groups: Sleep hygiene education and control group. After that, they were evaluated for anxiety, depression, and sleep quality levels and trained on an episodic memory task. They were tested immediately after (short-term test) and also 1 week later (long-term test). This procedure was also performed before the sleep hygiene education and was taken as baseline level. We found that episodic memory performance for young adults improved for the SHE group after intervention but not for older adults, and no improvements in emotional variables were observed. Despite not observing a significant effect of the intervention for young and older adults regarding the sleep quality scores, we consider that there may be an improvement in sleep physiology that is not subjectively perceived, but would also have a positive impact on memory processes. These results show that even a sleep hygiene education of 1 week could improve cognition in young adults when acute memory and sleep impairment occurs, in this case, due to the isolation by COVID-19 pandemic. However, we suggest that longer interventions should be implemented for older adults who already experience a natural decline in cognitive processes such as episodic memory formation.

Reward association impairs recognition of incidentally encoded negative information: Electrophysiological evidence

Previous studies investigating the effect of reward on emotional episodic memory have produced inconsistent results. In this study, through two experiments using event-related potentials (ERPs), we investigated the effect of reward association on the encoding and retrieval of incidentally encoded emotional information, and examined whether this effect changes over time. Participants in the two experiments were asked to discriminate the emotional valence of color images under reward or no-reward condition and incidentally encode them. Immediate (in Experiment 1) or 24-hour delayed (in Experiment 2) recognition after encoding was tested. In Experiments 1 and 2, reward (relative to no-reward) significantly improved the recognition of positive and neutral items, but significantly reduced the recognition of negative items. During encoding, the significant ERP reward effects (significantly more positive ERP amplitude for rewarded items than for non-rewarded ones) for positive and neutral images were widely distributed from 200 to 1500 ms after image onset, while those for negative stimuli occurred mainly from 200 to 500 ms. During retrieval, the significant ERP reward effects for positive and neutral items occurred in the two experiments, but the reversed ERP reward effects for negative items were found only in Experiment 1. The results of the present study suggest that reward association affects the encoding and retrieval of emotional images by enhancing memory processing efficiency of positive and neutral items, while impairing recognition of negative items, thus yielding a robust and sustained modulation over frontal/frontocentral or centroparietal/parietal areas where mechanisms of reward and emotion processing operate in conjunction.

Effects of non-invasive transcutaneous auricular vagus nerve stimulation (taVNS) on emotional episodic memory: a matter of timing?

Effects of non-invasive transcutaneous auricular vagus nerve stimulation (taVNS) on emotional episodic memory: a matter of timing?

Time-dependent emotional memory transformation: Divergent pathways of item memory and contextual dependency.

Emotional memory can persist strikingly long, but it is believed that not all its elements are protected against the fading effects of time. So far, studies of emotional episodic memory have mostly investigated retention up to 24h postencoding and revealed that central emotional features (items) are usually strengthened, while contextual binding of the event is reduced. However, even though it is known for neutral memories that central versus contextual elements evolve differently with longer passage of time, the time-dependent evolution of emotional memories remains unclear. Hypothetically, compared to neutral memories, emotional item memory becomes increasingly stronger, accompanied by accelerated decay of-already fragile-links with their original encoding contexts, resulting in progressive reductions in contextual dependency. Here, we tested these predictions in a large-scale study. Participants encoded emotional and neutral episodes, and were assessed 30 minutes (N = 40), 1 day (N = 40), 1 week (N = 39), or 2 weeks (N = 39) later on item memory, contextual dependency, and subjective quality of memory. The results show that, with the passage of time, emotional memories were indeed characterized by increasingly stronger item memory and weaker contextual dependency. Interestingly, analyses of the subjective quality of memories revealed that stronger memory for emotional items with time was expressed in familiarity, whereas increasingly smaller contextual dependency for emotional episodes was reflected in recollection. Together, these findings uncover the time-dependent transformation of emotional episodic memories, thereby shedding light on the ways healthy and maladaptive human memories may develop. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

The Effects of Hormonal Contraception on Auditory Emotional Memory

Emotional episodic memory is an important cognitive mechanism that has been extensively studied, however, auditory emotional memory in particular has yet to be thoroughly understood. In addition, sex hormones have been found to affect brain structure and regulate regions of the brain that support higher order cognitive functions. Considering the global usage of oral hormonal contraceptive pills, it is vitally important to investigate the effects of oral contraceptives on executive function, including memory. The aim of the present study was to investigate the extent to which oral contraceptives influence recall for an emotional auditory episodic memory compared to a neutral memory. Participants (N = 90; 45 on an oral contraceptive, 45 naturally cycling) performed a free recall task for an emotional and a neutral auditory story, and their recalls were categorized into gist and detail elements and rated for accuracy. Recall accuracy for an emotional or neutral auditory story was not different between women on oral hormonal contraceptives and women who were naturally cycling, however, both groups of women recalled more information regarding the neutral story compared to the emotional story. These findings inform how the use of hormonal contraceptive pills, combined with high emotional valence, may impact the content and accuracy of recalled episodic events.

Investigating the effects of sleep and sleep loss on the different stages of episodic emotional memory: A narrative review and guide to the future.

For two decades, sleep has been touted as one of the primary drivers for the encoding, consolidation, retention, and retrieval of episodic emotional memory. Recently, however, sleep’s role in emotional memory processing has received renewed scrutiny as meta-analyses and reviews have indicated that sleep may only contribute a small effect that hinges on the content or context of the learning and retrieval episodes. On the one hand, the strong perception of sleep’s importance in maintaining memory for emotional events may have been exacerbated by publication bias phenomena, such as the “winner’s curse” and “file drawer problem.” On the other hand, it is plausible that there are sets of circumstances that lead to consistent and reliable effects of sleep on emotional memory; these circumstances may depend on factors such as the placement and quality of sleep relative to the emotional experience, the content and context of the emotional experience, and the probes and strategies used to assess memory at retrieval. Here, we review the literature on how sleep (and sleep loss) influences each stage of emotional episodic memory. Specifically, we have separated previous work based on the placement of sleep and sleep loss in relation to the different stages of emotional memory processing: (1) prior to encoding, (2) immediately following encoding during early consolidation, (3) during extended consolidation, separated from initial learning, (4) just prior to retrieval, and (5) post-retrieval as memories may be restructured and reconsolidated. The goals of this review are three-fold: (1) examine phases of emotional memory that sleep may influence to a greater or lesser degree, (2) explicitly identify problematic overlaps in traditional sleep–wake study designs that are preventing the ability to better disentangle the potential role of sleep in the different stages of emotional memory processing, and (3) highlight areas for future research by identifying the stages of emotional memory processing in which the effect of sleep and sleep loss remains under-investigated. Here, we begin the task of better understanding the contexts and factors that influence the relationship between sleep and emotional memory processing and aim to be a valuable resource to facilitate hypothesis generation and promote important future research.

Determinants of quality, specificity, and stability of emotional episodic memories in a fine-dining context

For theoretical and practical reasons, it is of great interest to understand how accurate and persistent episodic memories of enjoyable experiences are formed and maintained, for example, in the context of gastronomy and other instances of experience design. Here, we investigated factors that might affect the quality (a measure of coherence) of immediate and long-term emotional episodic memories of individual dishes of a long and complex dinner in a fine-dining restaurant. We also assessed long-term recognition memory for pictures of the dishes. Intra-class correlations revealed good immediate emotional episodic memory, which remained stable over three months. Contributing factors to these kinds of memory were assessed with path modelling. The quality of emotional episodic memory was enhanced by the hedonic intensity of the most valued dishes during the meal and was impaired with the hedonic intensity of the least valued dishes. Enjoying the final dish positively affects emotional memory after the experience. Interestingly, when diners reported to have been distracted from the meal, presumably by communicating with their meal companions about the food, it had a positive effect on the long-term emotional episodic memory. Personality traits of the diners had no substantial impact on either type of memory. Alcohol intake during the meal modestly affected recognition memory but – interestingly – had no statistically significant effect on emotional episodic memory. Altogether, this study provides novel information about the main determinants of the precision and temporal stability of emotional episodic memory and nonemotional recognition memory for a meal. These findings contribute to the psychological foundations of designing memorable experiences in gastronomy and other areas. Implications for gastronomyKnowing what factors may determine whether a gastronomic experience would be memorable to diners is the holy grail of any chef. The design of a gastronomic experience should provide intense emotional moments to the diners aiming to increase the quality of emotional memory of those moments. Different factors contribute to this stability, for instance, how the diner interacts with the food and the food itself. In this regard, serving in a dining course very tasty and less delicious dishes thereafter can enhance the memorability of the former, but not so much of the latter, as it may be disturbing for the diner. Critically, enjoying the final dish positively affects emotional memory after the experience. In addition, most gastronomic events are shared with companions. Far from being a distracting element, social relationships in a table seem to increase the memorability of the experience, as communication deeply elaborates and reinforces memory traces. In the reinforcement of emotional memories for foods, alcohol has a negligible effect. Although our findings have been obtained in a fine-dining context, the implications of our current findings might be generalizable to other, more standard contexts. The critical point is to focus on having positive specific episodes rather than having a positive global valuation. All these outcomes would converge to increase the probability of repeating the gastronomic experience, regardless of whether it is a high-level restaurant or a standard one.

EPISODIC MEMORY PROCESSES FOR NEUTRAL STIMULI IN THE EMOTIONAL CONTEXT

Emotional stimuli are processed differently in memory with respect to neutral stimuli; because they are more distinct, salient, and biologically significant. Episodic memory is about remembering the events as related to each other. In everyday life, because of the nature of episodic memories, emotional and neutral stimuli are exposed together, not separately. Thus, emotional stimuli become related to nearby neutral stimuli and affect their processing. In the emotional episodic memory literature, how emotional stimuli affect episodic memory processes about neutral stimuli has been widely studied. In addition to the approaches arguing this effect is either enhancing or weakening, there are also other approaches suggesting that it is selective. This selective effect emphasizes that emotion might enhance or weaken the memory for neutral stimuli with respect to different occasions. In addition to the item memory for nearby neutral stimuli, emotional stimuli have effects on the associative memory established with these stimuli. Research has shown that emotional stimuli affect item and associative memory in different ways. In summary, this review tries to analyze emotional episodic memory literature in the scope of neutral stimuli. For this aim, how emotional stimuli affect episodic memory for nearby neutral stimuli is evaluated extensively. Keywords Emotional stimuli, neutral stimuli, episodic memory, item memory, associative memory

Establishment of Emotional Memories Is Mediated by Vagal Nerve Activation: Evidence from Noninvasive taVNS.

Emotional memories are better remembered than neutral ones, but the mechanisms leading to this memory bias are not well understood in humans yet. Based on animal research, it is suggested that the memory-enhancing effect of emotion is based on central noradrenergic release, which is triggered by afferent vagal nerve activation. To test the causal link between vagus nerve activation and emotional memory in humans, we applied continuous noninvasive transcutaneous auricular vagus nerve stimulation (taVNS) during exposure to emotional arousing and neutral scenes and tested subsequent, long-term recognition memory after 1 week. We found that taVNS, compared with sham, increased recollection-based memory performance for emotional, but not neutral, material. These findings were complemented by larger recollection-related brain potentials (parietal ERP Old/New effect) during retrieval of emotional scenes encoded under taVNS, compared with sham. Furthermore, brain potentials recorded during encoding also revealed that taVNS facilitated early attentional discrimination between emotional and neutral scenes. Extending animal research, our behavioral and neural findings confirm a modulatory influence of the vagus nerve in emotional memory formation in humans.SIGNIFICANCE STATEMENT Emotionally relevant information elicits stronger and more enduring memories than nonrelevant information. Animal research has shown that this memory-enhancing effect of emotion is related to the noradrenergic activation in the brain, which is triggered by afferent fibers of the vagus nerve (VN). In the current study, we show that noninvasive transcutaneous auricular VN stimulation enhances recollection-based memory formation specifically for emotionally relevant information as indicated by behavioral and electrophysiological indices. These human findings give novel insights into the mechanisms underlying the establishment of emotional episodic memories by confirming the causal link between the VN and memory formation which may help understand the neural mechanisms underlying disorders associated with altered memory functions and develop treatment options.

Exploring the Facets of Emotional Episodic Memory: Remembering “What,” “When,” and “Which”

Our memories can differ in quality from one event to the next, and emotion is one important explanatory factor. Still, the manner in which emotion impacts episodic memory is complex: Whereas emotion enhances some aspects of episodic memory—particularly central aspects—it dampens memory for peripheral/contextual information. Extending previous work, we examined the effects of emotion on one often overlooked aspect of memory, namely, temporal context. We tested whether emotion would impair memory for when an event occurred. Participants (N = 116 adults) watched videos wherein negative and neutral images were inserted. Consistent with prior work, results showed that emotion enhanced and impaired memory, respectively, for “what” and “which.” Unexpectedly, emotion was associated with enhanced accuracy for “when”: We found that participants estimated that neutral images occurred relatively later, but there was no such bias for negative images. By examining multiple features of episodic memory, we provide a holistic characterization of the myriad effects of emotion.

Reframing the Past: Role of Memory Processes in Emotion Regulation

The ability to modulate undesirable emotions is essential for maintaining mental health. Negative emotions can arise both while experiencing and remembering an unpleasant event, which presents a persistent emotion regulation challenge because emotional memories tend to be particularly vivid and enduring. Despite the central role that memories play in our affective lives, little is known about the memory processes supporting successful regulation of emotions associated with long-term memories, which we refer to as retrospective emotion regulation. In this paper, we review the literature on the mechanisms of memory modification, which may contribute to the success of retrospective emotion regulation. In particular, we review rodent and human studies that examine the modification of conditioned fear associations and emotional episodic memories. Based on this literature, we conclude that memory reactivation plays a crucial role in memory modification. We discuss further the potential role of memory reactivation in mediating the success of cognitive reappraisal, which may be considered a special case of memory modification. We propose that the completeness, or strength, of reactivation during retrospective emotion regulation will be related to the likelihood of updating an episodic memory, reducing its emotional impact upon later recall. Understanding the role of memory processes in emotion regulation can help to inform research on memory-based treatments for affective disorders.

Neural substrates of long-term item and source memory for emotional associates: An fMRI study

Since Tulving's influential work on the distinction between familiarity and recollection-based retrieval, numerous studies have found evidence for differential contribution of these retrieval mechanisms on emotional episodic memory. Particularly, retrieval advantage for emotional, compared to neutral, information has been related to recollection-, but not familiarity-mediated processes. Neuroimaging studies suggest that this recollection-based retrieval for emotional information is related to stronger engagement of regions in the medial temporal lobe (MTL), posterior parietal cortex (PPC), and prefrontal cortex (PFC). In the present study, we investigated neural correlates related to long-term memory of neutral information that has been associated with emotional and neutral contexts, using functional magnetic resonance imaging (fMRI). During encoding, different neutral objects integrated with emotional or neutral scenes were presented. One week later, the encoded objects were intermixed with new ones and participants had to indicate whether the objects were previously seen or not, using the Remember/Know procedure (item memory). Furthermore, memory for the correct scene background category was also tested (contextual source memory). First, replicating previous findings, we observed a preference for recollection-dependent memory retrieval versus familiarity-dependent memory retrieval for those neutral objects encoded in emotional compared to neutral contexts. Second, consistent with these behavioral effects, objects encoded with emotional, compared to neutral, scenes produced larger memory-related activity in recollection-sensitive brain regions, including PPC and PFC regions. Third, correctly retrieved emotional compared to neutral contextual information was associated with increased activity in these brain areas. Together, these results suggest that memory for information encoded in emotional contexts is remarkably robust over time and mediated by recollection-based processes.

Predictors of involuntary and voluntary emotional episodic memories of virtual reality scenarios in Veterans with and without PTSD

ABSTRACT This study investigated predictors of involuntary and voluntary memories of stressful virtual reality scenarios. Thirty-two veterans of the two Persian Gulf Wars completed verbal memory tests and diagnostic assessments. They were randomly assigned to a Recounting (16) or a Suppression (16) condition. After immersion in the VR scenarios, the Recounting group described the scenarios and the Suppression group suppressed thoughts of the scenarios. One week later, participants completed surprise voluntary memory tests and another thought suppression task. The best predictors of voluntary memory were verbal memory ability, dissociation, and to a lesser extent, physiological arousal before and after scenarios. Dissociation and physiological stress responses selectively affected memory for neutral elements. Higher distress during scenarios impaired voluntary memory but increased the frequency of involuntary memories. Physiological stress responses promoted more frequent involuntary memories immediately after the scenarios. More frequent initial involuntary memories, tonic physiological arousal, and stronger emotional responses to dangerous events predicted difficulty inhibiting involuntary memories at follow-up. The effects of thought suppression were transient and weaker than those of other variables. The findings suggest that posttraumatic amnesia and involuntary memories of adverse events are more related to memory ability and emotional and physiological stress responses than to post-exposure suppression.

0111 Emotional Memory-Associated Voxel-Extent Reactivation During Episodic Memory Retrieval Varies as a Function of Post-Learning Sleep

Abstract Introduction Slow wave sleep (SWS) and rapid eye-movement (REM) sleep enhance neutral and emotional memory consolidation, respectively. Emotional episodic memory retrieval is also enhanced when encoding-specific functional brain patterns are reactivated at retrieval, especially in ventral visual stream and frontal brain regions as well as amygdala. Here we investigate how sleep impacts the association between memory-dependent brain pattern reactivation and episodic memory retrieval. Methods Healthy adults (N = 22; 11F, 11M; age: 19–29 years) were scanned during an incidental encoding task and a surprise recognition memory task 24h later. Overnight sleep was monitored with polysomnography. During encoding, participants viewed line drawings of negative, neutral, and positive images, each followed by their full-colored photo. At recognition, participants distinguished new from encoded line drawings. Brain reactivation was measured at the single-subject level as the percentage of voxels activated at encoding that were also activated during successful recognition (reactivation%); this metric was calculated independently in whole-brain and 3 ROI-based maps (inferior temporal lobe (ITL), medial prefrontal cortex, and amygdala). Multiple linear regression was performed to predict memory performance from functional brain reactivation and sleep physiology. Results In whole-brain analyses, the association between negative memory performance and reactivation% decreased with greater REM sleep amount. This interaction approached significance for positive, but was not significant for neutral, memory performance. Additionally, the association between neutral, but not emotional, memory performance and reactivation% decreased with greater amounts of SWS sleep. In ROI-based analyses, positive, but not negative or neutral, memory performance was independently predicted by REM sleep amount and ITL reactivation%. No effects of SWS amount were observed in ROI-based analyses. Conclusion Greater amounts of sleep decreased the association between brain reactivation and memory performance. Sufficient sleep may change cortical representations of episodic memories, resulting in less reliance on encoding-related reactivation during memory retrieval. Support NSF Grant BCS 1539361

Neural correlates of successful emotional episodic encoding and retrieval: An SDM meta-analysis of neuroimaging studies

Episodic memory for emotional events is typically enhanced and engages additional brain mechanisms relative to episodic memory for neutral events. Many functional magnetic resonance imaging (fMRI) studies have probed the neural basis of this emotional enhancement effect on encoding processes, while relatively fewer studies have examined retrieval. Neuroimaging meta-analysis methods can summarize the brain regions associated with emotional episodic memory that are consistently activated across multiple studies. A previous ALE (Activation Likelihood Estimation) meta-analysis identified consistent activations associated with successful encoding of episodic emotional memory in the amygdala, hippocampus, and in multiple neocortical regions (Murty et al., 2010). However, since that study, meta-analysis methods have improved, and many new relevant neuroimaging studies have been published. Moreover, although qualitative reviews have summarized brain activations related to the successful retrieval of emotional episodic memory, no corresponding quantitative meta-analyses have yet been reported. Here we conducted neuroimaging meta-analyses of successful emotional memory encoding and rretrieval using Seed-based d Mapping (SDM). Relevant neuroimaging studies reporting whole-brain fMRI correlates of successful encoding and retrieval of emotional episodic memory were selected for analysis. For successful emotional memory encoding, SDM activations were found bilaterally in the medial temporal lobe (amygdala, hippocampus, entorhinal cortex, perirhinal cortex, and parahippocampal cortex), bilaterally in visual processing regions (middle temporal, gyrus, fusiform gyrus and occipital cortex) and bilaterally in the temporal pole, orbitofrontal cortex, insula, putamen, and the inferior and middle temporal gyri. In contrast to the prior meta-analysis, SDM activations were not observed in the inferior frontal gyrus or in parietal regions. For successful emotional episodic memory retrieval, SDM activations were observed in the medial temporal lobe (bilateral amygdala, left hippocampus, and left entorhinal cortex and perirhinal cortex), visual processing regions (bilateral occipital cortex and right middle temporal gyrus), prefrontal cortex (bilateral orbitofrontal cortex, bilateral inferior frontal gyrus, bilateral precentral gyrus, left middle frontal gyrus, right frontal pole) and other regions in the left hemisphere including the temporal pole, insula, putamen, angular gyrus, and parietal opercular cortex. Considerable overlap was observed between the encoding and retrieval meta-analysis maps in the medial temporal lobe (bilateral amygdala, left hippocampus, entorhinal, and perirhinal cortex), visual processing regions (bilateral occipital cortex, right middle temporal gyrus), and other regions including the left orbitofrontal cortex, left insula, left putamen, left pallidum, and left temporal pole. The current findings add to current understanding of the role of the amygdala, hippocampus, and neocortical regions in the successful encoding and retrieval of emotional episodic memory, clarify and provide an important summary of the current literature in this area, and have implications for current theories of emotional episodic memory encoding and retrieval.

Emotional memory bias in binge drinking women

BackgroundHeightened emotionality and overrepresentation of memories are typical features of adolescence. Binge drinking (BD) during emerging adulthood has been linked to cognitive difficulties such as deficits in episodic memory. Despite that impairments in emotional functioning have been associated with the development of alcohol use disorders, particularly in females, the emotional sphere has been relatively unexplored in BDs. Therefore, the purpose of this study is to examine the effects of BD in emotional episodic memory from a gender perspective. MethodsOne hundred and eighty (96 females) university students were followed during two years (18–20 years old) and their alcohol use was recorded. In the last assessment, participants completed an emotional list-learning task. Generalized linear mixed models were applied separately for males and females, in accordance with sex differences in the development of emotion circuitry. ResultsIn females, BD was associated with an emotional memory bias in favour of negative information and lower recall of positive and neutral words. In addition, females BDs showed more false alarms for negative distractors. Whereas in males, no alcohol-related effects were found. ConclusionsFemale BDs present a negative memory bias, poor learning and delayed episodic recall linked to the interference of negative content, which suggests difficulties in disengaging attention to salient negative stimuli and a reduction of inhibitory capacities. This might result in greater vulnerability to alcohol-related emotional disturbances among women. Further research is needed to understand the role of emotional regulation in the escalation of alcohol abuse from a gender perspective.

Role of Emotional Appraisal in Episodic Memory in a Sample of Argentinean Preschoolers.

Emotional processing and episodic memory are closely related throughout childhood development. With respect to emotional episodic memory, available evidence shows that the consolidation of information is accompanied by an arousal that generates longer duration and persistence of the memory representations. In the case of early stages of development (i.e., first 5 years), it is less clear how these associations emerge and are modulated by individual and environmental factors. In this study, 116 4- to 5-years old Argentinean children from different socio-environmental contexts (i.e., favorable or unfavorable living conditions at home), performed a task of visual emotional memory in which they observed a set of 15 images with variable emotional valences (negative, neutral, and positive). The child’s task was to appraise each image using one of the following three possible valences: (a) drawings of faces with smiles (positive valence), (b) drawings of faces with tears and round mouth with edges down (negative valence), or (c) drawings of faces with horizontal mouth (neutral valence). Five years-old children exhibited greater accuracy appraisal. Individual differences in emotional accuracy appraisal allowed us to observe different performances in free recall of negative visual images. Accuracy appraisal did not vary between children with respect to gender, living conditions at home, or language ability. Seven to ten days after the emotional appraisal children were asked to tell the experimenter all the images they remembered (variables of interest: free recall of negative, positive, or neutral images). Results showed individual (age) differences. Specifically, 5-years-old children evoked more images than 4-years-old children. These findings contribute to the understanding of emotional memory in early developmental stages and raise the need to include emotional appraisal in the assessment of episodic memory.

The role of the basolateral amygdala in dreaming

Neuroimaging studies have repeatedly shown amygdala activity during sleep (REM and NREM). Consequently, various theorists propose central roles for the amygdala in dreaming – particularly in the generation of dream affects, which seem to play a major role in dream plots. However, a causal role for the amygdala in dream phenomena has never been demonstrated. The traditional first step in determining this role is to observe the functional effects of isolated lesions to the brain structure in question. However, circumscribed bilateral amygdala lesions are extremely rare. Furthermore, the treatment of the amygdala as a unitary structure is problematic, as the basolateral and centromedial amygdala (BLA and CMA) may serve very different functions.We analysed 23 dream reports collected from eight adult patients with bilateral calcification of the BLA as a result of a very rare genetic condition called Urbach-Wiethe Disease (UWD). We compared these dream reports to 52 reports collected from 17 matched controls. Given that the BLA has been implicated in various affective processes in waking life, we predicted that the emotional content of the patients' dreams would differ from that of controls. Due to the exploratory nature of this research, a range of different dream characteristics were analysed.A principal components analysis run on all data returned three key factors, namely pleasantness, length and danger. The UWD patients' dream reports were significantly more pleasant and significantly shorter and less complex than control reports. No differences were found in levels of threat or danger.The results support some current hypotheses concerning the amygdala's role in dreaming, and call others into question. Future research should examine whether these UWD patients show generally impaired emotional episodic memory due to BLA damage, which could explain some of the current findings.