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Memory monitoring ability is essential for the effectiveness of learning processes. Judgment of Learning (JOL), a metacognitive judgment, is commonly used to measure this ability. An ongoing debate questions whether JOL is an outcome of an inferential or recollective experience, as suggested by different hypotheses regarding the underlying cognitive mechanisms of this judgment. To address this question through a neuroscientific perspective, we aimed to investigate the temporal dynamic of JOL adopting event-related potential (ERP) methodology. Seventy-two young adults participated in an episodic memory task involving word-pairs as stimuli. Their JOLs were obtained through categorical choices in a delayed condition. Additionally, their memory performance was tested in the recognition phase. ERP components were compared for different JOL levels, as well as for the hit responses in the recognition test according to their JOL levels. The analyses showed that JOL processes are observable within an early time window after stimulus presentation, as evidenced by elicitation of the P100, N100, P200, N200, and P300 components across all JOL levels. However, only the amplitude of the N100 varied among these levels. A negative ERP component with 330-500 ms latency was also evident for all JOL levels in the central and parietal electrodes, which did not differ in amplitude. The analyses of the recognition phase ERPs showed that the hit responses did not exhibit a significant difference in the familiarity-related mid-frontal old/new effect (FN400) amplitude; however, those with high level of JOL elicited recollection-related parietal old-new effect with a smaller amplitude. These findings support both hypotheses suggesting that JOL is influenced by heuristics and the retrievability of information., Competing Interests: Declaration of competing interest Soner Yücetepe and Metehan Irak have no conflict of interest., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

I outline the perspective that searching the contents of memory is a form of mental time travel (MTT) in non-humans that is relatively tractable because it focuses on the contents of memory. I propose that an animal model of MTT requires three elements: (i) the animal remembers multiple events using episodic memory, (ii) the order of events in time is included in the representation, and (iii) the sequence of events can be searched to find a target that occurred at a particular time. I review experiments suggesting that rats represent multiple items in episodic memory (element 1) in order of occurrence (element 2) and engage in memory replay to search representations in episodic memory in sequential order to find information at particular points in the sequence (element 3). The cognitive building blocks needed for MTT may be quite old in the evolutionary timescale.This article is part of the theme issue 'Elements of episodic memory: lessons from 40 years of research'.

Tulving's concept of mental time travel (MTT), and the related distinction of episodic and semantic memory, have been highly influential contributions to memory research, resulting in a wealth of findings and a deeper understanding of the neurocognitive correlates of memory and future thinking. Many models have conceptualized episodic and semantic representations as existing on a continuum that can help to account for various hybrid forms. Nevertheless, in most theories, MTT remains distinctly associated with episodic representations. In this article, we review existing models of memory and future thinking, and critically evaluate whether episodic representations are distinct from other types of explicit representations, including whether MTT as a neurocognitive capacity is uniquely episodic. We conclude by proposing a new framework, the Multidimensional Model of Mental Representations (MMMR), which can parsimoniously account for the range of past, present and future representations the human mind is capable of creating. This article is part of the theme issue 'Elements of episodic memory: lessons from 40 years of research'.

Episodic memories are experienced as belonging to a self that persists in time. We review evidence concerning the nature of human episodic memory and of the sense of self and how these emerge during development, proposing that the younger child experiences a persistent self that supports a subjective experience of remembering. We then explore recent research in cognitive architectures for robotics that has investigated the possibility of forms of synthetic episodic and autobiographical memory. We show that recent advances in generative modeling can support an understanding of the emergence of self and of episodic memory, and that cognitive architectures which include a language capacity are showing progress towards the construction of a narrative self with autobiographical memory capabilities for robots. We conclude by considering the prospects for a more complete model of mental time travel in robotics and the implications of this modeling work for understanding human episodic memory and the self in time. This article is part of the theme issue 'Elements of episodic memory: lessons from 40 years of research'.

In Tulving's initial characterization, episodic memory was one of multiple memory systems. It was postulated, in pursuit of explanatory depth, as displaying proprietary operations, representations and substrates such as to explain a range of cognitive, behavioural and experiential phenomena. Yet the subsequent development of this research programme has, paradoxically, introduced surprising doubts about the nature, and indeed existence, of episodic memory. On dominant versions of the 'common system' view, on which a single simulation system underlies both remembering and imagining, there are no processes unique to memory to support robust generalizations with inductive potential. Eliminativism about episodic memory seems to follow from the claim that it has no dedicated neurocognitive system of its own. After identifying this under-noticed threat, we push back against modern eliminativists by surveying recent evidence that still indicates specialized mechanisms, computations and representations that are distinctly mnemic in character. We argue that contemporary realists about episodic memory can retain lessons of the common system approach while resisting the further move to eliminativism. This article is part of the theme issue 'Elements of episodic memory: lessons from 40 years of research'.

Ever since Tulving's influential 1985 article 'Memory and consciousness', it has become traditional to think of autonoetic consciousness as necessary for episodic memory. This paper questions this claim. Specifically, it argues that the construct of autonoetic consciousness lacks validity and that, even if it was valid, it would still not be necessary for episodic memory. The paper ends with a proposal to go back to a functional/computational characterization of episodic memory in which its characteristic phenomenology is a contingent feature of the retrieval process and, as a result, open to empirical scrutiny. The proposal also dovetails with recent taxonomies of memory that are independent of conscious awareness and suggests strategies to evaluate within- and between-individual variability in the conscious experience of episodic memories in human and non-human agents. This article is part of the theme issue 'Elements of episodic memory: lessons from 40 years of research'.

Many recent artificial intelligence (AI) systems take inspiration from biological episodic memory. Here, we ask how these 'episodic-inspired' AI systems might inform our understanding of biological episodic memory. We discuss work showing that these systems implement some key features of episodic memory while differing in important respects and appear to enjoy behavioural advantages in the domains of strategic decision-making, fast learning, navigation, exploration and acting over temporal distance. We propose that these systems could be used to evaluate competing theories of episodic memory's operations and function. However, further work is needed to validate them as models of episodic memory and isolate the contributions of their memory systems to their behaviour. More immediately, we propose that these systems have a role to play in directing episodic memory research by highlighting novel or neglected hypotheses as pursuit-worthy. In this vein, we propose that the evidence reviewed here highlights two pursuit-worthy hypotheses about episodic memory's function: that it plays a role in planning that is independent of future-oriented simulation, and that it is adaptive in virtue of its contributions to fast learning in novel, sparse-reward environments. This article is part of the theme issue 'Elements of episodic memory: lessons from 40 years of research'.

40 years ago, Endel Tulving published his hugely influential Elements of Episodic Memory (Oxford: Clarendon Press, 1983). For the first time, this discussed the details of episodic memory (i.e. the ability to remember personal past events), including a specific conscious experience. Ten years later, Tulving defined the ability to mentally project oneself in time to be the critical feature distinguishing episodic from semantic memory ('What is episodic memory?' Curr . Dir . Psychol . Sci . 2 , 67-70, doi:10.1111/1467-8721.ep10770899). In this conception, the conscious experience of episodic memory captures the experience of reliving a personal event as it was experienced in the past, while the same ability allows a potential symmetry between remembering the past, and our ability to project into an imagined future. With the recent passing of Endel Tulving, this theme issue offers an opportunity to question our understanding of mental time travel in full.This article is part of the theme issue 'Elements of episodic memory: lessons from 40 years of research'.

Mental time travel is often presented as a singular mechanism, but theoretical and empirical considerations suggest that it is composed of component processes. What are these components? Three hypotheses about the major components of mental time travel are commonly considered: (i) remembering and imagining might, respectively, rely on different processes, (ii) past- and future-directed forms of mental time travel might, respectively, rely on different processes, and (iii) the creation of episodic representations and the determination of their temporal orientation might, respectively, rely on different processes. Here, we flesh out the last of these proposals. First, we argue for 'representational continuism': the view that different forms of mental travel are continuous with regard to their core representational contents. Next, we propose an updated account of episodic recombination (the mechanism generating these episodic contents) and review evidence in its support. On this view, episodic recombination is a natural kind best viewed as a form of compositional computation. Finally, we argue that episodic recombination should be distinguished from mechanisms determining the temporal orientation of episodic representations. Thus, we suggest that mental travel is a singular capacity, while mental time travel has at least two major components: episodic representations and their temporal orientation. This article is part of the theme issue 'Elements of episodic memory: lessons from 40 years of research'.

While many aspects of cognition have been shown to be shared between humans and non-human animals, there remains controversy regarding whether the capacity to mentally time travel is a uniquely human one. In this paper, we argue that there are four ways of representing when some event happened: four kinds of temporal representation . Distinguishing these four kinds of temporal representation has five benefits. First, it puts us in a position to determine the particular benefits these distinct temporal representations afford an organism. Second, it provides the conceptual resources to foster a discussion about which of these representations is necessary for an organism to count as having the capacity to mentally time travel. Third, it enables us to distinguish stricter from more liberal views of mental time travel that differ regarding which kind(s) of temporal representation is taken to be necessary for mental time travel. Fourth, it allows us to determine the benefits of taking a stricter or more liberal view of mental time travel. Finally, it ensures that disagreement about whether some species can mentally time travel is not merely the product of unrecognized disagreement about which temporal representation is necessary for mental time travel. We argue for a more liberal view, on the grounds that it allows us to view mental time travel as an evolutionarily continuous phenomenon and to recognize that differences in the ways that organisms mentally time travel might reflect different temporal representations, or combinations thereof, that they employ. Our ultimate aim, however, is to create a conceptual framework for further discussion regarding what sorts of temporal representations are required for mental time travel.This article is part of the theme issue 'Elements of episodic memory: lessons from 40 years of research'.

Tulving's introduction of episodic memory and the metaphor of mental time travel has immensely enriched our understanding of human cognition. However, his focus on human psychology, with limited consideration of evolutionary perspectives, led to the entrenched notion that mental time travel is uniquely human. We contend that adopting a phylogenetic perspective offers a deeper insight into cognition, revealing it as a continuous evolutionary process. Adherence to the uniqueness of pre-defined psychological concepts obstructs a more complete understanding. We offer a concise natural history to elucidate how events that occurred hundreds of millions of years ago have been pivotal for our ability to mentally time travel. We discuss how the human brain, utilizing parts with ancient origins in a networked manner, enables mental time travel. This underscores that episodic memories and mental time travel are not isolated mental constructs but integral to our perception and representation of the world. We conclude by examining recent evidence of neuroanatomical correlates found only in great apes, which show great variability, indicating the ongoing evolution of mental time travel in humans.This article is part of the theme issue 'Elements of episodic memory: lessons from 40 years of research'.

In this article, we explore various arguments against the traditional distinction between episodic and semantic memory based on the metaphysical phenomenon of transitional gradation. Transitional gradation occurs when two candidate kinds A and B grade into one another along a continuum according to their characteristic properties. We review two kinds of arguments-from the gradual semanticization of episodic memories as they are consolidated, and from the composition of episodic memories during storage and recall from semantic memories-that predict the proliferation of such transitional forms. We further explain why the distinction cannot be saved from the challenges of transitional gradation by appealing to distinct underlying memory structures and applying our perspective to the impasse over research into 'episodic-like' memory in non-human animals. On the whole, we recommend replacing the distinction with a dynamic life cycle of memory in which a variety of transitional forms will proliferate, and illustrate the utility of this perspective by tying together recent trends in animal episodic memory research and recommending productive future directions. This article is part of the theme issue 'Elements of episodic memory: lessons from 40 years of research'.

Over the course of his research, Endel Tulving offered a number of somewhat different characterizations of episodic memory. Do they indicate that he changed his mind over time as to what episodic memory is, or did his core understanding of the nature of episodic memory stay the same? In this article, we offer some support for the latter claim, and in particular for thinking that, throughout his life, Tulving took as a defining feature of episodic memory the distinctive awareness of the self in time it involves. We argue that it is easier to see the continuities rather than the discontinuities in Tulving's writings once their historical context is taken into account, where this involves both the authors who influenced his thinking, as well as the intellectual climate at the different times he was writing. We also discuss two recent bodies of work on episodic memory that take aspects of Tulving's writings as their point of departure, but try to factor out into separate ingredients what he arguably saw as a unitary phenomenon. Considering aspects of the dialectic between them and Tulving's view might shed further light on some of the motivations behind the latter.This article is part of the theme issue 'Elements of episodic memory: lessons from 40 years of research'.

The best-known example of episodic memory in animals came from food-storing birds. One of the beauties of the food-storing system was that inherent in the behaviour were the elements that (at the time) made up episodic memory: what, where and when. While there were then already plenty of data on animals' ability to put together what and where, the addition of the time element in animals' memory and its testing was one that was both new and experimentally challenging. It has, however, led to an increasing variety of examples showing that animals can put together all three informational components. If episodic memories can be described as those memories that make any one of us who we are, why should non-human animals have such memories? Here, we argue that episodic memories play a significant functional role in the lives of real animals, in particular, enabling them to make decisions about how they might or should act in their future. We support our argument with data from a range of examples, focussing on data from the field.This article is part of the theme issue 'Elements of episodic memory: lessons from 40 years of research'.

The view that human memory is constructive implies that recollections are not necessarily an accurate reproduction of past events. An approach to study this constructive nature of memory is by examining memory errors. In this regard, conjunction errors-i.e. incorrect recollection of new stimuli integrated by components from two previously studied stimuli-have attracted important attention in human memory research. Do animals other than humans make conjunction errors? To investigate this issue, a choice task in which training was not involved was used. Bees experienced two to-be-remembered stimuli. At the test, they were presented with four stimuli: one of the original items (i.e. old), an item made by combining two features of the original items (i.e. conjunction), an item containing a previously presented feature and a new one (i.e. feature), and an item integrated solely by new features (i.e. new). Bumblebees remembered the old items. Importantly, when making memory errors, bumblebees selected conjunction and feature lures more often than new items. These results indicate that bumblebees, like humans, spontaneously make memory conjunction errors and suggest that invertebrates' memories might also be constructive in nature. I suggest that focusing on memory errors is a solid avenue to investigate episodic (like) memory in animals.This article is part of the theme issue 'Elements of episodic memory: lessons from 40 years of research'.

The predictive processing framework posits that one of the main functions of the brain is to anticipate the incoming information. Internal models facilitate interactions with the world by predicting future states against which actual evidence is compared. The difference between predicted and actual states, the prediction error (PE), signals novel information. However, how PE affects cognitive processing downstream is not fully understood: one such aspect pertains to how PE influences episodic memories, and whether those effect on memory differ across the lifespan. We examine the relationship between PE and episodic memory in children, young and older adults. We use a novel paradigm whereby rich visual narratives are used to build action schemas that enable probing different mnemonic aspects. To create different levels of PE, we manipulate the story endings to be either expected, neutral or unexpected with respect to the unfolded action. We show that (i) expected endings are better encoded than neutral endings and (ii) unexpected endings improve the encoding of mismatching events and other aspects of the narrative. These effects are differentially modulated across the lifespan with PE-driven encoding being more prominent in children and young adults and with schema integration playing a larger role on memory encoding in older adults. These results highlight the role of predictions by enriching past experiences and informing future anticipations.This article is part of the theme issue 'Elements of episodic memory: lessons from 40 years of research'.

Background: Semantic and short-term episodic memory are impaired in some brain disorders including Alzheimer's disease., Objective: Development and validation of an almost self-administered, but cognitively demanding four-minute test identifying very mild cognitive impairment (vMCI)., Methods: The innovative hedgehog PIC ture N aming and I mmediate R ecall ( PICNIR ) consisted of two parts. The first task was to write down the names of 20 black-and-white pictures to evaluate long-term semantic memory and language. The second task involves immediate recall and writing the names of as many previously named pictures as possible in one minute. The PICNIR is assessed using the number of naming errors (NE) and correctly recalled picture names (PICR). The PICNIR and a neuropsychological battery were administered to 190 elderly individuals living independently in the community. They were divided into those with vMCI (n = 43 with Montreal Cognitive Assessment (MoCA) 24 ± 3 points) and sociodemographically matched cognitively normal (CN) individuals (n = 147 with MoCA 26 ± 3). Both subgroups had predicted mean Mini-Mental State Examination scores of 28-29 points., Results: Compared to CN, vMCI participants made more NE (0.3 ± 0.6 versus 0.6 ± 0.9; p = 0.02) and recalled fewer PICR (8.9 ± 2.2 versus 6.8 ± 2.2; p  < 0.000001). Discriminative validity was satisfactory using the area under the ROC curve (AUC): 0.76 for PICR, 0.74 for MoCA, 0.67 for MoCA-five-word recall, and 0.59 for NE. The AUCs of PICR and MoCA were comparable and larger than those of MoCA five-point recall or NE. Logical Memory scores, RAVLT scores, Digit symbol, and animal fluency correlated with PICR., Conclusions: The picture-based PICNIR is an ultra-brief, sensitive cognitive test valid for assessing very mild cognitive impairment. Its effectiveness should be validated for other languages and cultures., Competing Interests: Declaration of conflicting interestsAles Bartos developed the PICNIR test. Sofie Diondet has no conflict of interest to report.

Deficits in memory, language, and other cognitive domains that impact an individual's ability to perform necessary tasks of daily living are symptoms of dementia, which is a major cause of death and disability in older adults. As the global population continues to age, deepening our understanding of dementia is crucial. Alzheimer's disease is the leading cause of dementia and accounts for between 60% and 80% of total dementia cases. Declines in episodic memory are considered a hallmark of Alzheimer's disease and occur early in disease progression. The cognitive effects of Alzheimer's disease differ from the cognitive changes expected in nonpathological or normal aging. While some cognitive changes are expected as a part of the aging processes, the declines in cognition associated with Alzheimer's disease are to a degree that the individual diagnosed with the disease is unable to function independently in activities of daily living. In this review, we will discuss how cognition is impacted by both normal and pathological aging, with a focus on Alzheimer's disease. We describe the progressive nature of Alzheimer's disease, as well as the effects of each stage of the disease on cognition., (© 2024. The Author(s), under exclusive license to Springer Nature Switzerland AG.)

Background: The relationship between obesity and episodic memory (i.e., conscious memory for specific events) is hypothesized to be bidirectional. Indeed, studies have shown that metabolic and bariatric surgery (MBS) is associated with episodic memory improvement, and better memory is associated with better postsurgical weight-loss outcomes. However, direct tests of the hypothesized bidirectional association between episodic memory and body mass index (BMI) in MBS are lacking, as few studies have employed repeated, prospective assessments of memory in conjunction with bidirectional modeling techniques., Objectives: The present study used latent change score analysis to examine the bidirectional longitudinal associations between episodic memory and BMI in the 2 years following MBS., Setting: University hospital; public practice., Methods: Episodic memory function and BMI were assessed in adults prior to MBS, and at 1, 6, 12, 18, and 24-months postsurgery., Results: A total of 124 participants (41% lost at 2-year follow-up) showed, on average, favorable weight-loss and episodic memory outcomes following MBS. Crucially, presurgery episodic memory predicted initial change in BMI at 1-month postsurgery, and postsurgery episodic memory at 1- and 6-months predicted change in BMI at 6- and 12-months postsurgery. No evidence was found for pre- and postsurgery BMI predicting changes in episodic memory., Conclusions: Results supported a unidirectional prospective relationship between episodic memory and weight change following MBS, such that better memory pre- and postsurgery predicted improved weight-loss outcomes. These findings highlight the likely importance of episodic memory function for weight change and support the potential benefit of targeting memory processes to improve weight-loss outcomes., (Copyright © 2024 American Society for Metabolic and Bariatric Surgery. Published by Elsevier Inc. All rights reserved.)

The retrosplenial cortex (RSC) is a key component of the brain's memory systems, with anatomical connections to the hippocampus, anterior thalamus, and entorhinal cortex. This circuit has been implicated in episodic memory and many of these structures have been shown to encode temporal information, which is critical for episodic memory. For example, hippocampal time cells reliably fire during specific segments of time during a delay period. Although RSC lesions are known to disrupt temporal memory, time cells have not been observed there. In this study, we reanalyzed archival RSC neuronal firing data during the intertrial delay period from two previous experiments involving different behavioral tasks, a blocked alternation task and a cued T-maze task. For the blocked alternation task, rats were required to approach the east or west arm of a plus maze for reward during different blocks of trials. Because the reward locations were not cued, the rat had to remember the goal location for each trial. In the cued T-maze task, the reward location was explicitly cued with a light and the rats simply had to approach the light for reward, so there was no requirement to hold a memory during the intertrial delay. Time cells were prevalent in the blocked alternation task, and most time cells clearly differentiated the east and west trials. We also found that RSC neurons could exhibit off-response time fields, periods of reliably inhibited firing. Time cells were also observed in the cued T-maze, but they were less prevalent and they did not differentiate left and right trials as well as in the blocked alternation task, suggesting that RSC time cells are sensitive to the memory demands of the task. These results suggest that temporal coding is a prominent feature of RSC firing patterns, consistent with an RSC role in episodic memory., (© 2024 Wiley Periodicals LLC.)

It has been hypothesized that differential processing occurs along the longitudinal (anterior-posterior) axis of the hippocampus. One hypothesis is that spatial memory (during both encoding and retrieval) is associated with the posterior hippocampus. An alternative hypothesis is that memory encoding (either spatial or nonspatial) is associated with the anterior hippocampus and memory retrieval is associated with the posterior hippocampus. Of importance, during spatial memory encoding, the spatial-posterior hypothesis predicts posterior hippocampal involvement, whereas the encoding-retrieval hypothesis predicts anterior hippocampal involvement. To distinguish between these hypotheses, we conducted a coordinate-based fMRI activation likelihood estimation (ALE) meta-analysis of 26 studies (with a total of 435 participants) that reported hippocampal activity during spatial memory encoding and/or spatial memory retrieval. Both spatial memory encoding and spatial memory retrieval produced extensive activity along the longitudinal axis of the hippocampus as well as the entorhinal cortex, the perirhinal cortex, and the parahippocampal cortex. Critically, the contrast of spatial memory encoding and spatial memory retrieval produced activations in both the anterior hippocampus and the posterior hippocampus. That spatial memory encoding produced activity in both the anterior and posterior hippocampus can be taken to reject strict forms of the spatial-posterior hypothesis, which stipulates that all forms of spatial memory produce activity in the posterior hippocampus, and the encoding-retrieval hypothesis, which stipulates that all forms of encoding versus retrieval produce activity in only the anterior hippocampus. Our results indicate that spatial memory encoding can involve the anterior hippocampus and the posterior hippocampus., (© 2024 Wiley Periodicals LLC.)

In this research article, a spiking neural network-based simulation of the hippocampus is performed to model the functionalities of episodic memory. The purpose of the simulation is to find a computational model through the biological architecture of the hippocampus and correct values for their architectural biological parameters to support the episodic memory functionalities. The episodic store of the model is represented by the collection of events, where each event is further subdivided into coactive activities of experience. The model has tried to mimic the three functionalities of episodic memory, which are pattern separation, pattern association, and their recallings. In pattern separation model used the dentate biological connectivity to generate almost different output patterns corresponding to similar input patterns to reduce interference between two similar memory traces so that ambiguity can be reduced during recalling. In pattern association, an STDP based event encoding and forgetting mechanism are used to mimic the encoding function of the CA3 region in which the coactive activities get associated with each other. A decoder is proposed based on CA1, which can answer the stored event related queries. Along with these functionalities model also supports recalling and encoding based forgetting. Experimental work is performed on the model for the given set of events to check for the pattern separation efficiency, pattern completion efficiency and to check the capability of decoding the answer. An empirical analysis of the results is done and compared with the SMRITI model of episodic memory.

Introduction: Widowhood and divorce are extremely stressful life events that are associated with dementia, but the neurobiological underpinnings of this risk remain unknown. Amyloid beta (Aβ) load may explain influences of chronic stress, commonly seen in disruptive marital transitions, on cognitive decline., Methods: We examined whether Aβ quantified by tracer uptake on positron emission tomography mediates associations between marital dissolution and executive functioning and episodic memory performance using data from 543 cognitively normal (CN) participants from the Alzheimer's Disease Neuroimaging Initiative., Results: Marriage dissolution was associated with increased Aβ burden ( β  = 0.56; P  = 0.015) and worse memory performance ( β  = -0.09; P  = 0.003). Aβ levels were a significant mediator for the relationship between marriage dissolution and memory (average causal mediation effect = -0.007; P  = 0.029)., Discussion: Findings suggest that stressful life events, such as the dissolution of one's marriage, might exert an effect on Alzheimer's disease proteinopathy, which may subsequently influence poor cognition. Highlights: Marital dissolution was associated with increased amyloid beta (Aβ) and memory declines.Aβ burden mediated associations between marital dissolution and memory.Findings were robust to potential non-linear influences of age.Mediation results were not observed when stratifying marital groups by sex., Competing Interests: S.W. has received funding from UKRI Innovate UK. Professor C.R.M. has received research grant funding from NIHR, Innovate UK, Michael J. Fox Foundation, Alzheimer's Research UK, and Tom and Sheila Springer Charity. A.C., R.A., P.P., and L.J.S. declare no conflicting interests related to this work. Author disclosures are available in the supporting information., (© 2024 The Author(s). Alzheimer's & Dementia: Diagnosis, Assessment & Disease Monitoring published by Wiley Periodicals LLC on behalf of Alzheimer's Association.)

The hippocampus is functionally specialized along its longitudinal axis with intricate interactions with cortical systems, which is crucial for understanding development and cognition. Using a well-established connectopic mapping technique on two large resting-state functional MRI datasets, we systematically quantified topographic organization of the hippocampal functional connectivity (hippocampal gradient) and its cortical interaction in developing brains. We revealed hippocampal functional hierarchy within the large-scale cortical brain systems, with the anterior hippocampus preferentially connected to an anterior temporal (AT) pathway and the posterior hippocampus embedded in a posterior medial (PM) pathway. We examined the developmental effects of the primary gradient and its whole-brain functional interaction. We observed increased functional specialization along the hippocampal long axis and found a general whole-brain connectivity shift from the posterior to the anterior hippocampus during development. Using phenotypic predictive modeling, we further delineated how the hippocampus is differentially integrated into the whole-brain cortical hierarchy underlying episodic memory and identified several key nodes within PM/AT systems. Our results highlight the importance of hippocampal gradient and its cortical interaction in development and for supporting episodic memory., Competing Interests: Competing interests statement:The authors declare no competing interest.

Context has long been regarded as an important element of long-term memory, and episodic memory in particular. The ability to remember not only the object or focus of a memory but also contextual details allow us to reconstruct integrated representations of events. However, despite its prevalence in the memory literature, context remains difficult to define and identify, with different studies using context to refer to different sets of stimuli or concepts. These varying definitions of context have not prevented it from being a key element of many models of memory. Within these models, context is usually explicitly encoded as an element of an event and processed through different neural pathways to other elements of the event, such as objects. Here we challenge the notion that context in memory is encoded. We offer an alternative where context in memory takes a variety of forms depending on the question being asked. We propose events are simply encoded, but the focus of retrieval (object) and context are not defined until recall., (Copyright © 2024. Published by Elsevier Ltd.)

Background: Episodic memory naturally deteriorates with age, and its deficits are widely recognized as the most significant feature and the most sensitive indicator of cognitive decline. It has been suggested that adopting a healthy lifestyle can play a protective role in preserving episodic memory. This study aimed to systematically examine the relationship between lifestyle factors (social activities, leisure activities, physical activities, internet use, smoking, alcohol drinking, and sleep quality) and episodic memory in middle-aged and older adults., Methods: The current study included 10,392 participants from the Chinese Health and Retirement Longitudinal Survey. A linear mixed model was used to explore the associations between lifestyle factors and episodic memory performance and the age- and sex-specific effects of the association., Results: Low-frequency alcohol drinking, higher engagement in social, leisure, and physical activities, increased internet use, and improved sleep quality were associated with better episodic memory performance in middle-aged and older adults. Stratified analyses demonstrated that internet use significantly correlated with episodic memory performance in middle-aged adults but not in older adults. On the other hand, sleep quality showed a significant association with episodic memory performance in women but not in men., Conclusions: This study highlights the association between various lifestyle factors and episodic memory performance, with variations observed based on age and sex. Adopting healthy lifestyle factors can have positive effects on episodic memory in middle-aged adults, emphasizing the importance of adhering to healthy lifestyles from middle age onwards to counteract episodic memory decline., (© 2024. The Author(s).)

Episodic autobiographical memory (EAM) is a long-term memory system of personally experienced events with their context - what, where, when - and subjective elements, e.g., emotions, thoughts, or self-reference. EAM formation has rarely been studied in a controlled, real-life-like paradigm, and there is no predictive model of long-term retrieval from self-rated subjective experience at encoding. The present longitudinal study, with three surprise free recall memory tests immediately, one-week and one-month after encoding, investigated incidental encoding of EAM in an immersive virtual environment where 30 participants either interacted with or observed specific events of varying emotional valences with simultaneous physiological recordings. The predictive analyses highlight the temporal dynamics of the predictors of EAM from subjective ratings at encoding: common characteristics related to sense of remembering and infrequency of real-life encounter of the event were identified over time, but different variables become relevant at different time points, such as the emotion and mental imagery or prospective aspects. This dynamic and time-dependent role of memory predictors challenges traditional views of a uniform influence of encoding factors over time. Current evidence for the multiphasic nature of memory formation points to the role of different mechanisms at play during encoding but also consolidation and subsequent retrieval., (© 2024. The Author(s).)

The purpose of the present study was to examine the acute effect of a single aerobic or strength training session on memory of cognitively preserved older adults. In this randomized controlled clinical trial, in the first visit the participants (52.2% men, aged 68.65 ± 2.81 years-old, BMI 26.94 ± 4.09), were randomly allocated in one of three groups: AG (aerobic exercise group), SG (strength exercise group, submitted to five exercises with 15 repetitions each), and CG (control group). Participants had a short-term memory assessment (word list memory test) followed by a single exercise session, and were retested immediately after. 24 h later, participants were submitted to a long-term memory assessment about the story that was presented in the previous day. Results showed that the SG group had a significant improvement in the word list test, when comparing pre- and post-intervention scores, suggesting that a single strength training session significantly enhances short-term memory in this population., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Endel Tulving defined episodic memory as consisting of a spatiotemporal context. It enables us to recollect personal experiences of people, things, places, and situations. In other words, it is made up of what, where, and when components. However, this definition does not include arguably the most important aspect of episodic memory: the why. Understanding why we remember has important implications to better understand how our memory system works and as a potential target of intervention for memory impairment. The intrinsic and extrinsic factors related to why some experiences are better remembered than others have been widely investigated but largely independently studied. How these factors interact with one another to drive an event to become a lasting memory is still unknown. This review summarizes research examining the why of episodic memory, where we aim to uncover the factors that drive core features of our memory. We discuss the concept of episodic memory examining the what, where, and when, and how the why is essential to each of these key components of episodic memory. Furthermore, we discuss the neural mechanisms known to support our rich episodic memories and how a why signal may provide critical modulatory impact on neural activity and communication. Finally, we discuss the individual differences that may further drive why we remember certain experiences over others. A better understanding of these elements, and how we experience memory in daily life, can elucidate why we remember what we remember, providing important insight into the overarching goal of our memory system., (© 2024. The Author(s).)

The (re-)construction of past and future personal experiences, termed mental time travel (MTT), is highly adaptive and contributes to self-related beliefs and attitudes. Mounting evidence suggests that self-efficacy (SE), the belief that one can overcome obstacles on their own account, is functionally related to MTT. In the present study, we used novel methods for the analysis of MTT narratives based on natural language processing (NLP) to investigate the relation between SE and MTT. We demonstrated that self-efficacious participants remembered and imagined experiences which were semantically less similar and contained a wider variety of contents. Additionally, increased SE was related to a positive reappraisal of personal episodes and reports of a more active role within mental scenarios. In conclusion, NLP appears to be a valuable method to quantify changes to the (re-)construction of personal experience that might support cognitive and emotional functioning., (© 2024. The Author(s).)

As the internet is becoming more and more accessible and prevalent, there has been growing interest in determining the effect of internet use on human cognition, particularly memory. However, much less is known about how internet use frequency is related to episodic memory, which refers to the memory of past events as opposed to facts (i.e., semantic memory). Episodic memory is very relevant to the internet because of the notion that the internet is a form of transactive memory, which requires people to retrieve how information was accessed (i.e., episodic memory) rather than the information itself (i.e., semantic memory). By analyzing data from 36, 542 participants with 44.06% females and a mean age of 46.63 years old from the Understanding Society using multivariate and univariate analysis of variances (ANOVA), the current study found that the frequency of internet use is positively related to episodic memory (assessed using the immediate recall and delayed word recall tasks). These results provide support to the notion that the internet is a form of transactive memory and the "use it, or lose it" theory., (© 2024. The Author(s).)

Memory retrieval has been extensively studied in relation to the encoding processes that precede access to stored information. Event related potentials (ERP) research has compared brain potentials elicited during the study phase of successful and unsuccessful retrieval, finding greater activation for the subsequent retrieval information. In this work we were interested in exploring the neural markers associated to subsequent recognition when similar memories are subsequently encoded. We used a Subsequent Memory paradigm in which we manipulated the number of similar items within a category (2 or 6) that participants encoded. Manipulating the number of similar encoded items within a category allowed us to test whether encoding markers of subsequent recognition depend solely on memory trace strength or, on the contrary, successful recognition is influenced by subsequently presented similar memories, and consequently may not be reflected in higher activation in such cases. After a 20-minute period, participants performed a recognition task providing one of a three-option judgement: "old", "similar" and "new", which allowed us to test if the amplitude of ERP waveforms varied based on the similarity judgement of the unrecognized encoded item. We did not observe a significant parietal subsequent memory effect, however, old hits and similar false alarms were both significantly different from similar correct rejections and old false alarms in ERP retrieval. These findings suggest that differences in brain responses between conditions are specifically related to the retrieval process and not the encoding process, indicating potential differential effects on memory during retrieval. Moreover, it is also possible that differences in brain responses develop or change over the rest time between phases, influencing how these conditions manifest across different stages of information processing., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Emerging evidence suggests that autobiographical memory (ABM) is altered in Huntington's disease (HD). While these impairments are typically attributed to frontostriatal dysfunction, the neural substrates of ABM impairment in HD remain unexplored. To this end, we assessed ABM in 30 participants with genetically confirmed HD (18 premanifest, 12 manifest) and 24 age-matched healthy controls. Participants completed the Autobiographical Interview to assess free and probed ABM recall and underwent structural brain imaging. Whole-brain voxel-based morphometry (VBM) was used to explore voxel-wise associations between ABM performance and grey matter intensity (False Discovery Rate corrected at q = 0.05). Relative to controls, HD participants displayed significantly less detailed ABM retrieval across free and probed recall conditions, irrespective of disease stage. Recall performance did not differ significantly between manifest and premanifest HD groups. VBM analyses indicated that poorer ABM performance was associated with atrophy of a distributed cortico-subcortical network. Key regions implicated irrespective of ABM condition included the bilateral occipital cortex, left precuneus, right parahippocampal gyrus and right caudate nucleus. In addition, probed ABM recall was associated with the superior and inferior frontal gyri, frontal pole, right hippocampus, nucleus accumbens, paracingulate gyrus and cerebellum. Overall, our findings indicate that ABM impairments in HD reflect the progressive degeneration of a distributed cortico-subcortical brain network comprising medial temporal, frontal, striatal and posterior parietal cortices. Our findings advance our understanding of the neurocognitive profile of HD, providing an important foundation for future interventions to support memory function in this population., (© 2024 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.)

Different cortical systems to the hippocampus were activated using fMRI during different types of episodic memory task. For object with scene location episodic memory, the activations were high in cortical systems involved in spatial processing, including the ventromedial visual and medial parahippocampal system. These activations for the medial parahippocampal system were higher in the right hemisphere. The activations in the face and object processing ventrolateral visual cortical stream regions FFC, PIT, V8 and TE2p were higher in the object-location in scene task than the reward-location task, and were higher in the right hemisphere. For reward-location in scene episodic memory, activations were also high in the ventromedial visual cortical spatial stream to the hippocampus, but were also selectively high in storage in key reward cortical regions (ventromedial prefrontal 10r, 10v, 10d; pregenual anterior cingulate d32, p24, p32, s32; and medial orbitofrontal cortex reward-related pOFC, 11l, OFC). For word-pair episodic memory, activations were lower in the ventromedial visual and medial parahippocampal spatial cortical stream, and were higher in language-related regions in Broca's area (44, 45, 47l), and were higher in the left hemisphere for these regions and for the many highly connected inferior frontal gyrus regions in the left hemisphere. Further, effective connectivity analyses during the episodic memory tasks showed that the direction of connectivity for these systems was from early visual cortical regions V2-V4 to the ventromedial visual cortical regions VMV1-3 and VVC for spatial scene processing; was from the pregenual anterior cingulate and orbitofrontal cortex reward systems to the hippocampal system; and was from the FFC/V8/PIT system to TE2p in the visual inferior temporal visual cortex, which has connectivity to lateral parahippocampal TF, which in turn has forward effective connectivity to the hippocampus., (© 2024 The Author(s). Human Brain Mapping published by Wiley Periodicals LLC.)

Previous research has established that the brain uses episodic memories to make continuous predictions about the world and that prediction errors, so the mismatch between generated predictions and reality, can lead to memory updating. However, it remains unclear whether prediction errors can stimulate updating in memories for naturalistic conversations. Participants encoded naturalistic dialogues, which were later presented in a modified form. We found that larger modifications were associated with increased learning of the modified statement. Moreover, memory for the original version of the statement was weakened after medium-strong prediction errors, which resulted from the interplay of modification extent and strength of previous memory. After strong prediction errors, both original and modification were well-remembered. Prediction errors thus play a role in keeping representations of statements and therefore socially relevant knowledge about others up to date.

During ongoing narratives, event boundaries trigger processes relevant for subsequent memory. Previous work has shown that novel, unrelated input presented at an event boundary can retroactively interfere with short-term retention of the preceding event. This interference was attributed to a perturbation of offset-related processes taking place within seconds after encoding and supporting the binding of elements into a coherent event memory. However, the temporal specificity of this memory interference and whether its impact extends to longer retention delays has not been addressed. Here, participants viewed either individual or pairs of short narrative movie clips. Susceptibility to interference at event boundaries was probed by presenting the second clip either immediately after the first, or with a 2s encoding delay. In free and cued recall, after 20 min and 24 h, only memory for movie clips that were immediately followed by a second clip was reduced compared to clips shown in isolation. Intact offset-related processes (as indexed by successful recall of the first movie) did not negatively affect encoding of the subsequent clip. Together, these results indicate that the 2s time-window immediately after an event is relevant for successful consolidation and long-term retention of memory.

Background: The neural correlates underlying late-life depressive symptoms and cognitive deterioration are largely unclear, and little is known about the role of chronic physical conditions in such association. This research explores both concurrent and longitudinal associations between late-life depressive symptoms and cognitive functions, with examining the neural substrate and chronic vascular diseases (CVDs) in these associations., Methods: A total of 4109 participants (mean age = 65.4, 63.0% females) were evaluated for cognitive functions through various neuropsychological assessments. Depressive symptoms were assessed by the Geriatric Depression Scale and CVDs were self-reported. T1-weighted magnetic resonance imaging (MRI), diffusion tensor imaging, and functional MRI (fMRI) data were acquired in a subsample ( n = 791)., Results: Cognitively, higher depressive symptoms were correlated with poor performance across all cognitive domains, with the strongest association with episodic memory ( r = ‒0.138, p < 0.001). Regarding brain structure, depressive symptoms were negatively correlated with thalamic volume and white matter integrity. Further, white matter integrity was found to mediate the longitudinal association between depressive symptoms and episodic memory ( indirect effect = -0.017, 95% CI -0.045 to -0.002) and this mediation was only significant for those with severe CVDs ( β = -0.177, p = 0.008)., Conclusions: This study is one of the first to provide neural evidence elucidating the longitudinal associations between late-life depressive symptoms and cognitive dysfunction. Additionally, the severity of CVDs strengthened these associations, which enlightens the potential of managing CVDs as an intervention target for preventing depressive symptoms-related cognitive decline.

Autonoetic consciousness (ANC), the ability to re-experience personal past events links episodic memory and self-consciousness by bridging awareness of oneself in a past event (i.e., during its encoding) with awareness of oneself in the present (i.e., during the reliving of a past event). Recent neuroscience research revealed a bodily form of self-consciousness, including the sense of agency (SoA) and the sense of body ownership (SoO) that are based on the integration of multisensory bodily inputs and motor signals. However, the relation between SoA and/or SoO with ANC is not known. Here, we used immersive virtual reality technology and motion tracking and investigated the potential association of SoA/SoO with ANC. For this, we exposed participants to different levels of visuomotor and perspectival congruency, known to modulate SoA and SoO, during the encoding of virtual scenes and collected ANC ratings 1 week after the encoding session. In a total of 74 healthy participants, we successfully induced systematic changes in SoA and SoO during encoding and found that ANC depended on the level of SoA experienced during encoding. Moreover, ANC was positively associated with SoA, but only for the scene encoded with preserved visuomotor and perspectival congruency, and such SoA-ANC coupling was absent for SoO and control questions. Collectively, these data provide behavioral evidence in a novel paradigm that links a key subjective component of bodily self-consciousness during encoding, SoA, to the subjective reliving of those encoded events from one's past, ANC., Competing Interests: The authors declare no competing financial interests., (Copyright © 2024 Meyer et al.)

The landscape of human memory and event cognition research has witnessed a transformative journey toward the use of naturalistic contexts and tasks. In this review, we track this progression from abrupt, artificial stimuli used in extensively controlled laboratory experiments to more naturalistic tasks and stimuli that present a more faithful representation of the real world. We argue that in order to improve ecological validity, naturalistic study designs must consider the complexity of the cognitive phenomenon being studied. Then, we review the current state of "naturalistic" event segmentation studies and critically assess frequently employed movie stimuli. We evaluate recently developed tools like lifelogging and other extended reality technologies to help address the challenges we identified with existing naturalistic approaches. We conclude by offering some guidelines that can be used to design ecologically valid cognitive neuroscience studies of memory and event cognition., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Disgust is a basic emotion that promotes pathogen avoidance and can contaminate nearby neutral stimuli. This study investigates how neutral stimuli, which have acquired disgust value through classical conditioning, are processed in episodic memory. The Category Conditioning paradigm was utilised to assign emotional significance to neutral stimuli, followed by a recognition test conducted immediately or 24 h after conditioning (Experiment 1). The results revealed that neutral stimuli that acquired disgust value were recognised with greater accuracy and higher liberal bias compared to other neutral stimuli in the recognition test conducted after 24 h, but not immediately. Present study also indicates that the memory enhancement observed with disgust did not manifest in the context of fear (Experiment 2). Additionally, the results varied when neutral stimuli associated with disgust were presented with disgusting stimuli in recognition test (Experiment 3). Thus, the present study demonstrates that the memory advantage of disgust extends to associated stimuli when they are presented in a list without disgusting stimuli.

On what basis do researchers posit that humans and other animals share cognitive capacities? We argue that such claims are not based on inherent, pre-existing similarities, but rather emerge through a two-step process, which we will call 'anthropofabrication'. In the initial stage, embodied action-based strategies and environmental context in human studies are ignored owing to the need for measurement and quantification. Consequently, cognitive terms become disconnected from the context to which we apply them, and human classificatory cognitive terms are transformed into broad explanatory terms, assumed to be 'species-neutral'. The second phase entails translating and applying these generalized explanatory terms to specific nonverbal animals in ways that serve to further cloak differences between animals and other species. Here, again, researchers selectively discard contextual information to facilitate the comparison with humans. To limit anthropofabrication, we should (re)acknowledge that cognitive abilities are not species-neutral and cannot be detached from embodied action, perception and their context of occurrence. We illustrate our points about anthropofabrication using the example of memory research. This article is part of the theme issue 'Minds in movement: embodied cognition in the age of artificial intelligence'.

Context: Limited data provides evidence-based insights on the association between comprehensive metrics of high-density lipoproteins (HDL) and cognitive performance, especially in midlife women for whom benefit might be the greatest., Objective: To assess the associations of serum HDL metrics including HDL lipid content [HDL cholesterol, phospholipid (HDL-PL), triglyceride], proteins/subclasses [apolipoprotein A-1 (apoA-1); small, medium, large, total HDL particle (HDL-P); and HDL size], and cholesterol efflux capacity with cognitive performance in midlife women., Methods: This prospective cohort study was conducted among 503 midlife women (1234 observations) from the Study of Women's Health Across the Nation HDL ancillary study. Joint models were applied to examine associations of HDL metrics assessed at midlife (50.2 ± 2.9 years, baseline of the current study) and their changes over midlife (6.1 ± 3.9 years of duration) with subsequent cognitive performance [working memory (Digit Span Backward Test), processing speed (Symbol Digit Modalities Test), and episodic memory immediate and delayed recall (East Boston memory test)] assessed repeatedly (maximum 5 times) 1.5 ± 1 years later over 7.72 ± 4.10 years of follow up., Results: Higher total HDL-P and smaller HDL size at midlife were associated with a better subsequent immediate recall, delayed recall and/or processing speed. Greater increase in HDL-PL, apoA-1, medium HDL-P, and total HDL-P and less increase in HDL size over midlife were associated with a better subsequent immediate and/or delayed recall., Conclusions: Enhancing specific serum HDL metrics during midlife could be promising in cognitive restoration, particularly memory, the initial and predominant symptom of Alzheimer's disease., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Endocrine Society. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com. See the journal About page for additional terms.)

Impaired episodic memory is the primary feature of early Alzheimer's disease (AD), but not all memories are equally affected. Patients with AD and amnestic Mild Cognitive Impairment (aMCI) remember pictures better than words, to a greater extent than healthy elderly. We investigated neural mechanisms for visual object recognition in 30 patients (14 AD, 16 aMCI) and 36 cognitively unimpaired healthy (19 in the "preclinical" stage of AD). Event-related brain potentials (ERPs) were recorded while participants performed a visual object recognition task. Hippocampal occupancy (integrity), amyloid (florbetapir) PET, and neuropsychological measures of verbal & visual memory, executive function were also collected. A right-frontal ERP recognition effect (500-700 ms post-stimulus) was seen in cognitively unimpaired participants only, and significantly correlated with memory and executive function abilities. A later right-posterior negative ERP effect (700-900 ms) correlated with visual memory abilities across participants with low verbal memory ability, and may reflect a compensatory mechanism. A correlation of this retrieval-related negativity with right hippocampal occupancy (r = 0.55), implicates the hippocampus in the engagement of compensatory perceptual retrieval mechanisms. Our results suggest that early AD patients are impaired in goal-directed retrieval processing, but may engage compensatory perceptual mechanisms which rely on hippocampal function., (© The Author(s) 2024. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Introduction: The role of information processing speed (IPS) on relationships between episodic memory (EM) and central remodeling features in amnestic mild cognitive impairment (aMCI) was investigated., Methods: Neuropsychological evaluations and multimodal magnetic resonance imaging were performed on 48 patients diagnosed with aMCI and 50 healthy controls (HC). Moderation models explored the moderating effect of IPS on associations between EM and imaging features at single-region, connectivity, and network levels., Results: IPS significantly enhanced the positive correlations between recall and cortical thickness of left inferior temporal gyrus. IPS also notably amplified negative correlations between recognition and functional connectivity (FC) of left inferior parietal lobe and right occipital, as well as between recall/recognition and nodal clustering coefficient of left anterior cingulate cortex., Discussion: IPS functioned as a moderator of associations between recall and neuroimaging metrics at the "single region-connectivity-network" level, providing new insights for cognitive rehabilitation in aMCI patients., Highlights: aMCI patients exhibited brain functional and structural remodeling alterations. IPS moderated relations between episodic memory and brain remodeling metrics. Therapy targeted at IPS can be considered for improving episodic memory in aMCI., (© 2024 The Author(s). Alzheimer's & Dementia published by Wiley Periodicals LLC on behalf of Alzheimer's Association.)

Music is a powerful medium that influences our emotions and memories. Neuroscience research has demonstrated music's ability to engage brain regions associated with emotion, reward, motivation, and autobiographical memory. While music's role in modulating emotions has been explored extensively, our study investigates whether music can alter the emotional content of memories. Building on the theory that memories can be updated upon retrieval, we tested whether introducing emotional music during memory recollection might introduce false emotional elements into the original memory trace. We developed a 3-day episodic memory task with separate encoding, recollection, and retrieval phases. Our primary hypothesis was that emotional music played during memory recollection would increase the likelihood of introducing novel emotional components into the original memory. Behavioral findings revealed two key outcomes: 1) participants exposed to music during memory recollection were more likely to incorporate novel emotional components congruent with the paired music valence, and 2) memories retrieved 1 day later exhibited a stronger emotional tone than the original memory, congruent with the valence of the music paired during the previous day's recollection. Furthermore, fMRI results revealed altered neural engagement during story recollection with music, including the amygdala, anterior hippocampus, and inferior parietal lobule. Enhanced connectivity between the amygdala and other brain regions, including the frontal and visual cortex, was observed during recollection with music, potentially contributing to more emotionally charged story reconstructions. These findings illuminate the interplay between music, emotion, and memory, offering insights into the consequences of infusing emotional music into memory recollection processes., (© 2024. The Psychonomic Society, Inc.)

Background: As 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)., Methods: In 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., Results: Using 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., Conclusions: Despite 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., (Copyright © 2024 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.)

The long-term fate of to-be-remembered information depends in part on the conditions of initial learning, including mental operations engaged via working memory. However, the mechanistic role of working memory (WM) processes in subsequent episodic memory (EM) remains unclear. Does re-exposure to word-pairs during WM recognition testing improve EM for those associations? Are benefits from WM re-exposure greater after an opportunity for retrieval practice compared to mere re-exposure to the memoranda? These questions are addressed in three experiments (N = 460) designed to assess whether WM-based recognition testing benefits long-term associative memory relative to WM-based restudying. Our results show null or negative benefits of WM recognition testing minutes later when initial WM accuracy was not considered. An EM benefit of WM recognition testing only emerges when the analyses are limited to pairs responded to correctly during WM. However, even when compared with accurate WM recognition, restudying can lead to similar associative EM benefits in specific experimental conditions. Taken together, the present results suggest that while WM re-exposure to studied pairs is beneficial to long-term associative memory, successful retrieval on initial tests may be a necessary but insufficient condition for the emergence of a "WM-based testing effect." We consider these results in relation to several hypotheses proposed to explain the testing effect in long-term memory (LTM). In view of empirical parallels with the LTM testing effect, we propose that similar processes influence the benefits of practice tests administered within the canonical boundaries of WM, suggesting continuities in memory over the short and long term., (© 2024. The Psychonomic Society, Inc.)

Many experiences unfold predictably over time. Memory for these temporal regularities enables anticipation of events multiple steps into the future. Because temporally predictable events repeat over days, weeks, and years, we must maintain-and potentially transform-memories of temporal structure to support adaptive behavior. We explored how individuals build durable models of temporal regularities to guide multistep anticipation. Healthy young adults (Experiment 1: N = 99, age range = 18-40 years; Experiment 2: N = 204, age range = 19-40 years) learned sequences of scene images that were predictable at the category level and contained incidental perceptual details. Individuals then anticipated upcoming scene categories multiple steps into the future, immediately and at a delay. Consolidation increased the efficiency of anticipation, particularly for events further in the future, but diminished access to perceptual features. Further, maintaining a link-based model of the sequence after consolidation improved anticipation accuracy. Consolidation may therefore promote efficient and durable models of temporal structure, thus facilitating anticipation of future events.

Background: Spectral features of human electroencephalographic (EEG) recordings during learning predict subsequent recall variability., New Method: Capitalizing on these fluctuating neural features, we develop a non-invasive closed-loop (NICL) system for real-time optimization of human learning. Participants play a virtual navigation-and-memory game; recording multi-session data across days allowed us to build participant-specific classification models of recall success. In subsequent closed-loop sessions, our platform manipulated the timing of memory encoding, selectively presenting items during periods of predicted good or poor memory function based on EEG features decoded in real time., Results: The induced memory effect (the difference between recall rates when presenting items during predicted good vs. poor learning periods) increased with the accuracy of neural decoding., Comparison With Existing Methods: This study demonstrates greater-than-chance memory decoding from EEG recordings in a naturalistic virtual navigation task with greater real-world validity than basic word-list recall paradigms. Here we modulate memory by timing stimulus presentation based on noninvasive scalp EEG recordings, whereas prior closed-loop studies for memory improvement involved intracranial recordings and direct electrical stimulation. Other noninvasive studies have investigated the use of neurofeedback or remedial study for memory improvement., Conclusions: These findings present a proof-of-concept for using non-invasive closed-loop technology to optimize human learning and memory through principled stimulus timing, but only in those participants for whom classifiers reliably predict out-of-sample memory function., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)