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Purpose: The purpose of this review was to evaluate the effects of physical activity on children's free recall, cued recall, and recognition episodic memory and to explore potential moderating factors. Methods: The following databases were searched: PubMed, ERIC, APA Psych Info, CINHAL, SPORTDiscus, and Google Scholar. Studies were included if: (1) participants were aged 4–18 years, (2) participants were typically developed, (3) participants were randomized to groups, (4) interventions employed gross movements, (5) sedentary group was used for control, (6) memory tests were quantitative, and (7) employed acute or chronic intervention. Results: 14 studies met inclusion criteria resulting in the analysis of data from 7 free recall, 7 cued recall, and 8 recognition memory tests. Physical activity was found to have a positive influence on tests free (g = 0.56), cued recall (g = 0.67), and no influence on tests of recognition (g = 0.06). While some moderator analyses were significant, the authors do not consider these results to be meaningful in application. Conclusions: The effects of acute and chronic physical activity enhance specific aspects of long-term episodic memory. These findings suggest physical activity interventions developed for children may be expected to benefit some, but not all, types of memory processing. [ABSTRACT FROM AUTHOR]

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.

Some people exhibit impressive memory for a wide array of semantic knowledge. What makes these trivia experts better able to learn and retain novel facts? We hypothesized that new semantic knowledge may be more strongly linked to its episodic context in trivia experts. We designed a novel online task in which 132 participants varying in trivia expertise encoded "exhibits" of naturalistic facts with related photos in one of two "museums." Afterward, participants were tested on cued recall of facts and recognition of the associated photo and museum. Greater trivia expertise predicted higher cued recall for novel facts. Critically, trivia experts but not non-experts showed superior fact recall when they remembered both features (photo and museum) of the encoding context. These findings illustrate enhanced links between episodic memory and new semantic learning in trivia experts, and show the value of studying trivia experts as a special population that can shed light on the mechanisms of memory.

INTRODUCTION: The influence of hippocampal connectivity on memory performance is well established in individuals with high educational attainment. However, the role of hippocampal connectivity in illiterate populations remains poorly understood. METHODS: Thirty-five illiterate adults were administered a literacy assessment (Test of Functional Health Literacy in Adults [TOFHLA]), structural and resting state functional magnetic resonance imaging, and an episodic memory test (Free and Cued Selective Reminding Test). Illiteracy was defined as a TOFHLA score < 53. We evaluated the correlation between hippocampal connectivity at rest and both free recall and literacy scores. RESULTS: Participants were mostly female (57.1%) and self-declared as being Black individuals (84.8%), with a median age of 50 years. The median TOFHLA literacy score was 28.0 [21.0; 42.5] out of 100 points and the median free recall score was 30.0 [26.2; 35] out of 48 points. The median gray matter volume of both the left and right hippocampi was 2.3 [2.1; 2.4] cm3. We observed a significant connectivity between both hippocampi and the precuneus and the ventral medial prefrontal cortex. The right hippocampal connectivity positively correlated with the literacy scores (β = 0.58, P = 0.008). There was no significant association between episodic memory and hippocampal connectivity. Neither memory nor literacy scores correlated with hippocampal gray matter volume. DISCUSSION: Low literacy levels correlated with hippocampal connectivity in illiterate adults. The lack of association with memory scores might be associated with low brain reserve in this sample. HIGHLIGHTS: A significant link was found between health literacy and hippocampal connectivity.Enhanced hippocampus- ventromedial prefrontal cortex connectivity suggests potential cognitive reserve improvement.Higher cognitive reserve may protect against hippocampal atrophy and neurodegeneration.Health literacy improvements could help prevent cognitive impairment in illiterate populations.Study highlights importance of considering structural racism in brain connectivity research.

BackgroundChildhood disadvantage is a prominent risk factor for cognitive and brain aging. Childhood disadvantage is associated with poorer episodic memory in late midlife and functional and structural brain abnormalities in the default mode network (DMN). Although age-related changes in DMN are associated with episodic memory declines in older adults, it remains unclear if childhood disadvantage has an enduring impact on this later-life brain-cognition relationship earlier in the aging process. Here, within the DMN, we examined whether its cortical microstructural integrity-an early marker of structural vulnerability that increases the risk for future cognitive decline and neurodegeneration-is associated with episodic memory in adults at ages 56-66, and whether childhood disadvantage moderates this association.MethodsCortical mean diffusivity (MD) obtained from diffusion magnetic resonance imaging was used to measure microstructural integrity in 350 community-dwelling men. We examined both visual and verbal episodic memory in relation to DMN MD and divided participants into disadvantaged and nondisadvantaged groups based on parental education and occupation.ResultsHigher DMN MD was associated with poorer visual memory but not verbal memory (β = -0.11, p = .040 vs β = -0.04, p = .535). This association was moderated by childhood disadvantage and was significant only in the disadvantaged group (β = -0.26, p = .002 vs β = -0.00, p = .957).ConclusionsLower DMN cortical microstructural integrity may reflect visual memory vulnerability in cognitively normal adults earlier in the aging process. Individuals who experienced childhood disadvantage manifested greater vulnerability to cortical microstructure-related visual memory dysfunction than their nondisadvantaged counterparts who exhibited resilience in the face of low cortical microstructural integrity.

Context contributes to multiple aspects of human episodic memory including segmentation and retrieval. The present studies tested if, in adult male and female mice, context influences the encoding of odors encountered in a single unsupervised sampling session of the type used for the routine acquisition of episodic memories. The three paradigms used differed in complexity (single vs. multiple odor cues) and period from sampling to testing. Results show that males consistently encode odors in a context-dependent manner: the mice discriminated novel from previously sampled cues when tested in the chamber of initial cue sampling but not in a distinct yet familiar chamber. This was independent of the interval between cue encounters or the latency from initial sampling to testing. In contrast, female mice acquired both single cues and the elements of multi-cue episodes, but recall of that information was dependent upon the surrounding context only when the cues were presented serially. These results extend the list of episodic memory features expressed by rodents and also introduce a striking and unexpected sex difference in context effects.

INTRODUCTION: Virtually all people with Down syndrome (DS) develop neuropathology associated with Alzheimers disease (AD). Atrophy of the hippocampus and entorhinal cortex (EC), as well as elevated plasma concentrations of neurofilament light chain (NfL) protein, are markers of neurodegeneration associated with late-onset AD. We hypothesized that hippocampus and EC gray matter loss and increased plasma NfL concentrations are associated with memory in adults with DS. METHODS: T1-weighted structural magnetic resonance imaging (MRI) data were collected from 101 participants with DS. Hippocampus and EC volume, as well as EC subregional cortical thickness, were derived. In a subset of participants, plasma NfL concentrations and modified Cued Recall Test scores were obtained. Partial correlation and mediation were used to test relationships between medial temporal lobe (MTL) atrophy, plasma NfL, and episodic memory. RESULTS: Hippocampus volume, left anterolateral EC (alEC) thickness, and plasma NfL were correlated with each other and were associated with memory. Plasma NfL mediated the relationship between left alEC thickness and memory as well as hippocampus volume and memory. DISCUSSION: The relationship between MTL gray matter and memory is mediated by plasma NfL levels, suggesting a link between neurodegenerative processes underlying axonal injury and frank gray matter loss in key structures supporting episodic memory in people with DS.

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Background: Evidence on associations of remnant cholesterol (RC) and its variability with cognitive function is still lacking. Objective: To explore the association of RC and its variability with cognitive function. Methods: Participants were recruited from a population-based cohort, the China Health and Retirement Longitudinal Study (CHARLS). Cognitive function was assessed by a standardized questionnaire from CHARLS, with domains of episodic memory and mental intactness. A linear mixed effects model was used to analyze the association of RC with cognitive function, along with its variability (calculated as standard deviation [SD], coefficient of variation [CV], variability independent of the mean [VIM]), with results expressed as β (95%CI). Potential subgroup differences in the association of RC and its variability with cognitive function were also explored. Results: 4234 participants were eventually included, with mean (SD) age of 57.4 (8.0) years. Each 10 mg/dL increase in RC was associated with 0.053 (95%CI: 0.096, 0.009) points, 0.021 (95%CI: 0.042, 0.000) points, 0.032 (95%CI: 0.064, 0.001) points decrease in global cognitive function, episodic memory, and mental intactness scores, respectively. Compared with the first tertile (T1) group of RC variability (calculated as SD, VIM), T3 showed a lower level in global cognition and episodic memory after multivariate adjustment. The potential modification effects of educational level on RC and its variability in relation to cognitive function were also identified. Conclusions: Among Chinese middle-aged and older adults, higher RC level were associated with worse cognitive function. Greater RC variability was also associated with worse cognitive performance, especially in memory function. [ABSTRACT FROM AUTHOR]

ABSTRACT Virtual reality exposure therapy (VRE) has been used in the treatment of combat‐related PTSD since the late 1990s and was recently adapted to treat PTSD due to military sexual trauma (MST). With content specifically tailored to MST‐related contexts, we present the case study of a military veteran who participated in the open clinical trial examining the feasibility of VRE in the treatment of MST‐related PTSD (Loucks et al. 2019). We illustrate VRE's use in activating the trauma memory to facilitate therapeutic emotional processing across sessions and overall symptom reduction. The case study includes common challenges that may occur during VRE and relevant recommendations. The discussion will include lessons learned from the case study and the open clinical trial, recommendations for the flexible application of VRE, and the ongoing developments in the latest version of the VRE system, informed by feedback acquired from the clinicians and patients who experienced it in the initial clinical trial. [ABSTRACT FROM AUTHOR]

We know much about people’s problematic reactions—such as distressing intrusions—to negative, stressful, or traumatic past events. But emerging evidence suggests people react similarly to negative and potentially-traumatic future events. Given similar processes underlie remembering the past and imagining the future more generally, we wondered how similar involuntary memories, or intrusions, are for experienced vs. anticipated events. We focused primarily on intrusions because they are a transdiagnostic reaction to traumatic events. We asked subjects to report either a very stressful event they had experienced in the past 6 months, or one they anticipated they could experience in the next 6 months. We measured the frequency of intrusions about these reported events, and intrusions’ phenomenological characteristics (such as emotional intensity), negative appraisals about their meaning, and reactions to them more generally. Overall, we found intrusions about experienced vs. anticipated autobiographical events were similarly troubling. This pattern supports the idea that anticipating the future can be aversive and elicit post-traumatic-stress-like symptoms, just as remembering the past can. Our findings have implications for theoretical models of traumatic-stress and treatment of traumatic-stress symptoms. [ABSTRACT FROM AUTHOR]

From the earliest moments in their lives, infants begin to build memories about their past and accumulate knowledge about the world. In this article, we focus on the distinction between memory for specific events and memory for general information, and the ongoing debate about which type of memory provides the foundation for the development of the other. Some researchers argue that specific memory developmentally precedes general memory, whereas others support the opposite position. Our literature review suggests that the latter position is inconsistent with many empirical findings and theoretical principles of memory captured by computational models capable of accounting for these findings. We propose that just good enough mnemonic acuity could be a starting point for memory development, and that it can support both specific and generalized memories. [ABSTRACT FROM AUTHOR]

AbstractStress is known to be a risk factor for deficits in working memory creating profound cognitive disturbances resulting in lingering impairments and losses in social and occupational functioning. Although a body of research has identified mindfulness as a potential means of mitigating deficits in working memory, there is a paucity of studies on the association between mindfulness and deficits in working memory among those who have experienced COVID-19 traumatic stress. This exploratory cross-sectional study sought to examine the mitigating effect of mindfulness on COVID-19 stress impacting working memory. The sample included 484 college students in Israel and the USA. Correlation and multiple regression analyses indicated that COVID-19 stress had a modest, inverse association with both a self-report and task-based indicator of working memory. In separate models predicting the different operationalizations of working memory, results revealed different effects for Israeli and USA students. Mindfulness was significantly associated with task-based but not self-reported working memory. The results offered evidence for a small but significant effect of mindfulness as moderating the impact of COVID-19 stress on working memory deficits. This exploratory, cross-­sectional study, used a convenience sample limiting the generalizability and its ability to test causal effects, calling for replication. [ABSTRACT FROM AUTHOR]

Episodic memory is organized in both spatial and temporal contexts. The hippocampus is crucial for episodic memory and has been demonstrated to encode spatial and temporal information. However, how the representations of space and time interact in the hippocampal memory system is still unclear. Here, we recorded the activity of hippocampal CA1 neurons in mice in a variety of one-dimensional navigation tasks while systematically varying the speed of the animals. For all tasks, we found neurons simultaneously represented space and elapsed time. There was a negative correlation between the preferred space and lap duration, e.g., the preferred spatial position shifted more toward the origin when the lap duration became longer. A similar relationship between the preferred time and traveled distance was also observed. The results strongly suggest a competitive and integrated representation of space-time by single hippocampal neurons, which may provide the neural basis for spatiotemporal contexts. [Display omitted] • Hippocampal CA1 single neurons concurrently represent space and time • The preferred location of some cells shifts with lap duration • The preferred time of some cells shifts with lap distance • There is a competitive interaction between space and time To study how the representation of space and time interact in the episodic memory system, Chen et al. showed that hippocampal CA1 neurons simultaneously represented space and elapsed time, and the neuronal firing reflected a trade-off or competition between space and time by shifting their fields in space or time. [ABSTRACT FROM AUTHOR]

This prospective, randomized, placebo-controlled study assessed the effects of Ashwagandha root extract (ARE) on cognition, energy, and mood in adults with self-reported cognitive and energy problems. Healthy subjects aged 30–75 years were randomized to receive ashwagandha (Withania somnifera) root extract (ARE) 600 mg/day (n = 60)/identical placebo (n = 60) orally for 8 weeks. Cognitive function was assessed at baseline and week 8 using a Computerized Mental Performance Assessment System (COMPASS). Secondary outcomes were Profile of Mood States Abbreviated Version (POMS-A), Mental Fatigue Scale (MFS) and Behavior Rating Inventory of Executive Function-Adult (BRIEF-A) for effects on mood, mental fatigue and executive function, respectively, assessed at baseline, week 4 and 8. Greater improvement (p < .05) from baseline scores were seen with ARE as against placebo for COMPASS items episodic memory, working memory and accuracy of attention. ARE also improved the POMS-A, MFS and BRIEF-A scores from baseline suggesting an improvement in mood, vigor, and an increase in the executive functioning respectively with ARE. The herb was well tolerated and had a good patient compliance with no serious adverse events reported in either of the groups. This study suggests that a dose of 600 mg a day can improve cognition, energy, and mood in adults with self-reported cognitive and energy problems. [ABSTRACT FROM AUTHOR]

The hippocampus is a brain region that is essential for the initial encoding of episodic memories. However, the consolidation of these memories is thought to occur in the neocortex, under guidance of the hippocampus, over the course of days and weeks. Communication between the hippocampus and the neocortex during hippocampal sharp wave-ripple oscillations is believed to be critical for this memory consolidation process. Yet, the synaptic and circuit basis of this communication between brain areas is largely unclear. To address this problem, we perform in vivo whole-cell patch-clamp recordings in the frontal neocortex and local field potential recordings in CA1 of head-fixed mice exposed to a virtual-reality environment. In mice trained in a goal-directed spatial task, we observe a depolarization in frontal principal neurons during hippocampal ripple oscillations. Both this ripple-associated depolarization and goal-directed task performance can be disrupted by chemogenetic inactivation of somatostatin-positive (SOM+) interneurons. In untrained mice, a ripple-associated depolarization is not observed, but it emerges when frontal parvalbumin-positive (PV+) interneurons are inactivated. These results support a model where SOM+ interneurons inhibit PV+ interneurons during hippocampal activity, thereby acting as a disinhibitory gate for hippocampal inputs to neocortical principal neurons during learning. [ABSTRACT FROM AUTHOR]

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'. [ABSTRACT FROM AUTHOR]

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'. [ABSTRACT FROM AUTHOR]

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'. [ABSTRACT FROM AUTHOR]

One apparent feature of mental time travel is the ability to recursively embed temporal perspectives across different times: humans can remember how we anticipated the future and anticipate how we will remember the past. This recursive structure of mental time travel might be formalized in terms of a 'grammar' that is reflective of but more general than linguistic notions of absolute and relative tense. Here, I provide a foundation for this grammatical framework, emphasizing a bounded (rather than unbounded) recursive function that supports mental time travel to a limited temporal depth and to actual and possible scenarios. Anticipated counterfactual thinking, for instance, entails three levels of mental time travel to a possible scenario ('in the future, I will reflect on how my past self could have taken a different future action') and is centrally implicated in complex human decision-making. This perspective calls for further research into the mechanisms, ontogeny, functions and phylogeny of recursive mental time travel, and revives the question of links with other recursive forms of thinking such as theory of mind. This article is part of the theme issue 'Elements of episodic memory: lessons from 40 years of research'. [ABSTRACT FROM AUTHOR]

The concept of episodic memory (EM) faces significant challenges by two claims: EM might not be a distinct memory system, and EM might be an epiphenomenon of a more general capacity for mental time travel (MTT). Nevertheless, the observations leading to these arguments do not preclude the existence of a mechanically and functionally distinct EM system. First, modular systems, like cognition, can have distinct subsystems that may not be distinguishable in the system's final output. EM could be such a subsystem, even though its effects may be difficult to distinguish from those of other subsystems. Second, EM could have a distinct and consistent low-level function, which is used in diverse high-level functions such as MTT. This article introduces the scenario construction framework, proposing that EM crucially rests on memory traces containing the gist of an episodic experience. During retrieval, EM traces trigger the reconstruction of semantic representations, which were active during the remembered episode, and are further enriched with semantic information, to generate a scenario of the past experience. This conceptualization of EM is consistent with studies on the neural basis of EM and resolves the two challenges while retaining the key properties associated with EM. This article is part of the theme issue 'Elements of episodic memory: lessons from 40 years of research'. [ABSTRACT FROM AUTHOR]

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'. [ABSTRACT FROM AUTHOR]

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'. [ABSTRACT FROM AUTHOR]

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'. [ABSTRACT FROM AUTHOR]

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'. [ABSTRACT FROM AUTHOR]

Mental time travel is the projection of the mind into the past or future, and relates to experiential aspects of episodic memory, and episodic future thinking. Framing episodic memory and future thinking in this way causes a challenge when studying memory in animals, where demonstration of this mental projection is prevented by the absence of language. However, there is good evidence that non-human animals pass tests of episodic memory that are based on behavioural criteria, meaning a better understanding needs to be had of the relationship between episodic memory and mental time travel. We argue that mental time travel and episodic memory are not synonymous, and that mental time travel is neither a requirement of, nor an irrelevance to, episodic memory. Mental time travel can allow improved behavioural choices based on episodic memory, and work in all species (including humans) should include careful consideration of the behavioural outputs being measured. This article is part of the theme issue 'Elements of episodic memory: lessons from 40 years of research'. [ABSTRACT FROM AUTHOR]

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'. [ABSTRACT FROM AUTHOR]

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'. [ABSTRACT FROM AUTHOR]

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'. [ABSTRACT FROM AUTHOR]

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'. [ABSTRACT FROM AUTHOR]

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'. [ABSTRACT FROM AUTHOR]

Prior research has used innovative paradigms to show that some non-human animal species demonstrate behavioural choices (i.e. foraging for a food item at a specific location, and at a time that guarantees it has not yet decayed), reflecting episodic-like or 'WWW' memory (memory for 'what' happened, 'where' and 'when'). These results raised the question of whether similar approaches could be used to examine memory in young children in order to reduce verbal demands. The present research examines the extent to which children's WWW memory aligns with memory-based choices in 3- to 5-year-olds (n = 95; study 1) and in 7- to 11-year-olds and adults (n = 168; study 2). Results indicate that preschoolers' struggle with choice-based tasks probably reflects difficulty integrating their WWW memory with an understanding that certain items decay over time. Moreover, a convergence between verbal recall measures and choice-based measures is observable in 7-year-olds and beyond, reflecting a stronger integration of memory signals, understanding of state transformation, and decision-making. This article is part of the theme issue 'Elements of episodic memory: lessons from 40 years of research'. [ABSTRACT FROM AUTHOR]

Children's episodic future-thinking is typically assessed using experimental tasks that measure whether children select an item with future utility. Although these tasks—inspired by Tulving's seminal 'spoon test' (Tulving E. 2005 Episodic memory and autonoesis: uniquely human? In The missing link in cognition: origins of self-reflective consciousness [eds HS Terrace, J Metcalfe], pp. 3–56. Oxford, UK: Oxford University Press. [doi:10.1093/acprof:oso/9780195161564.001.0001])—are passed around age 4, they tell us little about the functional significance of children's episodic future-thinking in their day-to-day lives. We highlight how a naturalistic approach can shed light on this issue, and present a small study where we recruited mothers to report on their children's (N = 12, 3- and 4-year-olds and 6- and 7-year-olds) future-thinking over a 7-day period. We used a thematic analysis to understand why children express future thoughts and derived the following themes: (1) expressing future desires and/or intentions, (2) future-oriented information-seeking, (3) connecting present actions with future outcomes, and (4) predicting future mental/physiological states. We compare these themes with recent accounts of the functional significance of future-thinking in adults and conclude that children largely express their future-thinking verbally to request information or support from their parent—likely because they do not yet possess enough control/autonomy to independently act for their own future. Our findings both complement and extend an experimental approach and further elucidate the functional significance of mental time travel in children. This article is part of the theme issue 'Elements of episodic memory: lessons from 40 years of research'. [ABSTRACT FROM AUTHOR]

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'. [ABSTRACT FROM AUTHOR]

Episodic memory involves the conscious recollection of personally experienced events and when absent, results in profound losses to the typical human conscious experience. Over the last 2.5 decades, the debate surrounding whether episodic memory is unique to humans has seen a lot of controversy and accordingly has received significant research attention. Various behavioural paradigms have been developed to test episodic-like memory; a term designed to reflect the behavioural characteristics of episodic memory in the absence of evidence for consciously experienced recall. In this review, we first outline the most influential paradigms that have been developed to assess episodic-like memory across a variety of non-human taxa (including mammals, birds and cephalopods), namely the what–where–when memory, incidental encoding and unexpected question, and source memory paradigms. Then, we examine whether various key features of human episodic memory are conceptually represented in episodic-like memory across phylogenetically and neurologically diverse taxa, identifying similarities, differences and gaps in the literature. We conclude that the evidence is mixed, and as episodic memory encompasses a variety of cognitive structures and processes, research on episodic-like memory in non-humans should follow this multifaceted approach and assess evidence across various behavioural paradigms that each target different aspects of human episodic memory. This article is part of the theme issue 'Elements of episodic memory: lessons from 40 years of research'. [ABSTRACT FROM AUTHOR]

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'. [ABSTRACT FROM AUTHOR]

Declarative memory encompasses episodic and semantic divisions. Episodic memory captures singular events with specific spatiotemporal relationships, whereas semantic memory houses context-independent knowledge. Behavioural and functional neuroimaging studies have revealed common and distinct neural substrates of both memory systems, implicating mesiotemporal lobe (MTL) regions such as the hippocampus and distributed neocortices. Here, we explored declarative memory system reorganization in patients with unilateral temporal lobe epilepsy (TLE) as a human disease model to test the impact of variable degrees of MTL pathology on memory function. Our cohort included 31 patients with TLE and 60 age- and sex-matched healthy controls, and all participants underwent episodic and semantic retrieval tasks during a multimodal MRI session. The functional MRI tasks were closely matched in terms of stimuli and trial design. Capitalizing on non-linear connectome gradient-mapping techniques, we derived task-based functional topographies during episodic and semantic memory states, in both the MTL and neocortical networks. Comparing neocortical and hippocampal functional gradients between TLE patients and healthy controls, we observed a marked topographic reorganization of both neocortical and MTL systems during episodic memory states. Neocortical alterations were characterized by reduced functional differentiation in TLE across lateral temporal and midline parietal cortices in both hemispheres. In the MTL, in contrast, patients presented with a more marked functional differentiation of posterior and anterior hippocampal segments ipsilateral to the seizure focus and pathological core, indicating perturbed intrahippocampal connectivity. Semantic memory reorganization was also found in bilateral lateral temporal and ipsilateral angular regions, whereas hippocampal functional topographies were unaffected. Furthermore, leveraging MRI proxies of MTL pathology, we observed alterations in hippocampal microstructure and morphology that were associated with TLE-related functional reorganization during episodic memory. Moreover, correlation analysis and statistical mediation models revealed that these functional alterations contributed to behavioural deficits in episodic memory, but again not in semantic memory in patients. Altogether, our findings suggest that semantic processes rely on distributed neocortical networks, whereas episodic processes are supported by a network involving both the hippocampus and the neocortex. Alterations of such networks can provide a compact signature of state-dependent reorganization in conditions associated with MTL damage, such as TLE. [ABSTRACT FROM AUTHOR]

Each collective trauma holds its own particularities and forms of horror. When the violence is exerted by the government responsible for the care of the population it is termed state terrorism. The traumatic experience and its subsequent negation create a profound dissociation between two narratives: the explicit, which conceals the true facts, and the implicit, which remains unconscious and unbridgeable. In the gap between the two, life becomes suspended. From a Jungian perspective, this can be understood as the interruption of the process of translation and integration (terms that I will explore in some depth) from implicit sensory phenomena to an explicit representational narrative. This profoundly affects the development of the ego‐self axis. In turn, it creates a special challenge for analytic technique that calls for new ways of listening to, and meeting the patient in, that non‐verbal, unrepresented territory. Drawing upon clinical material, an embodied perspective of Jungian clinical work is offered to show how the inclusion of the body of patient and analyst enables access to the non‐represented, though implicitly encoded, traumatic affective memories stored in the somatic unconscious. [ABSTRACT FROM AUTHOR]

The tendency of falsely remembering events that did not happen in the past increases with age. This is particularly evident in cases in which features presented at study are re-presented at test in a recombined constellation (termed rearranged pairs). Interestingly, older adults also express high confidence in such false memories, a tendency that may indicate reduced metacognitive efficiency. Within an existing cohort study, we aimed at investigating age-related differences in memory metacognitive efficiency (as measured by meta d' ratio) in a sample of 1522 older adults and 397 young adults. The analysis showed an age-related deficit in metacognition which was more pronounced for rearranged pairs than for new pairs. We then explored associations between cortical thickness and memory metacognitive efficiency for rearranged pairs in a subsample of 231 older adults. By using partial least square analysis, we found that a multivariate profile composed by ventromedial prefrontal cortex, insula, and parahippocampal cortex was uniquely associated with between-person differences in memory metacognitive efficiency. These results suggest that the impairment in memory metacognitive efficiency for false alarms is a distinct age-related deficit, above and beyond a general age-related decline in memory discrimination, and that it is associated with brain regions involved in metacognitive processes. [ABSTRACT FROM AUTHOR]

True and false memories recruit a number of shared brain regions; however, they are not completely overlapping. Extensive sex differences have been identified in the brain during true memories and, recently, we identified sex differences in the brain during false memories. In the current fMRI study, we sought to determine whether sex differences existed in the location and extent of overlap between true and false memories. True and false memories activated a number of shared brain regions. Compared to females, males produced a greater number of overlapping brain regions (8 versus 2 activations for males and females, respectively) including the prefrontal cortex, parietal cortex, and early/late visual processing cortices (including V1) in males and prefrontal and parietal cortices in females. Males had significantly higher similarity between true and false memory activation maps, revealed by our novel multi-voxel pattern correlation analysis. Moreover, higher similarity between true and false memory activation maps was associated with higher false memory rates. The current results suggest that true and false memories are more similar in males than females. The significant brain–behavior relationship also suggests that males may be more susceptible to false memory errors due to their highly similar true memory–false memory cortical representations. [ABSTRACT FROM AUTHOR]

False memories during testimony are an enormous challenge for criminal trials. Exposure to post-event misinformation can lead to inadvertent creation of false memories, known as the misinformation effect. We investigated anodal transcranial direct current stimulation (tDCS) on the left inferior parietal lobe (IPL) during recall testing to enhance accurate recall while addressing the misinformation effect. Participants (N = 60) watched a television series depicting a fictional terrorist attack, then received an audio recording with misinformation, consistent information, and control information. During cued recall testing, participants received anodal or sham tDCS. Results revealed a robust misinformation effect in both groups, with participants falsely recalling on average 26.6% of the misinformed items. Bayesian statistics indicated substantial evidence in favour of the null hypothesis that there was no difference between groups in the misinformation effect. Regarding correct recall however, the anodal group exhibited significantly improved recall for items from the original video. Together, these results demonstrate that anodal tDCS of the left IPL enhances correct recall of the episodes from the original event without affecting false recall of misinformation. The findings support the IPL's role in recollection and source attribution of episodic memories. [ABSTRACT FROM AUTHOR]

Objectives The present study used a cross-lagged panel design with longitudinal data to test if there is a reciprocal relationship between cognitive control beliefs and cognition (e.g. executive functioning and episodic memory) over 10 years, whether frequency of engaging in stimulating cognitive activities mediated this relationship, and if these relationships varied by age. Methods Data were collected as part of the second (M2, 2004–2005) and third (M3, 2013–2014) waves of the Midlife in the United States Study. The analysis sample included 2,532 participants with all variables at M2 and M3. Participants' ages ranged from 33 to 83 (M  = 54.92, standard deviation = 11.13) at M2. Results There was a reciprocal relationship between cognitive control beliefs and executive functioning. Higher executive functioning was related to greater maintenance of cognitive control beliefs for older, not younger, adults. Higher cognitive control beliefs were related to less decline in executive functioning. Though cognitive control beliefs predicted 10-year changes in episodic memory, the inverse relationship was not supported. Frequency of engaging in stimulating cognitive activities mediated the relationship between executive functioning and 10-year changes in cognitive control beliefs, but not cognitive control beliefs and 10-year changes in cognition. Conclusions Cognitive control beliefs are a promising mechanism to help protect against age-related declines in both executive functioning and episodic memory. Moreover, executive functioning also affects cognitive control beliefs. Specifically, those with higher executive functioning engage more frequently in stimulating cognitive activities, which helps maintain higher cognitive control beliefs. [ABSTRACT FROM AUTHOR]

This article analyses the ways in which the memory of transnational traumatic events of war and conflict of the past have been represented at Wellington's waterfront and whether the site, with its multitude of memorial plaques, can be read as a lieu de mémoire. The study focuses on three commemorative plaques: the memorial plaque to those New Zealanders who took part in the Spanish Civil War (2011); the commemorative plaque to the Polish children of Pahīatua (2004); and the memorial plaque commemorating the arrival of the United States Marine Corps to New Zealand (1951/2000). It, first, examines the memory entrepreneurs behind the commemoration of the events the plaques depict and analyse whether these agents engaged in bottom-up or top-down mnemonic practices and activities (or a mixture of these). Second, it analyses the significance of these memorials in the collective memory of contemporary Aotearoa/New Zealand. [ABSTRACT FROM AUTHOR]

Background: Idiopathic normal pressure hydrocephalus (iNPH) can present with both episodic amnestic syndrome and biomarkers of Alzheimer's disease (AD) pathology. Objective: To examine the associations between amnestic syndrome and cerebrospinal fluid (CSF) AD biomarkers in iNPH and the CSF tap test response in iNPH patients with amnestic syndrome. Methods: We used the Free and Cued Selective Reminding Test to divide iNPH into amnestic and non-amnestic patients. We compared their clinical, biological, and radiological characteristics and examined the reversibility of gait spatiotemporal parameters and neuropsychological performances after a CSF tap test. Univariate and multiple linear regression models examined the association between memory performance and clinical-biological characteristics. Results: Sixty-two non-amnestic patients (mean age 77.0±7.0 years, 38.7% female) and thirty-eight amnestic patients (mean age 77.0±5.9 years, 36.8% female) presented similar levels of AD biomarkers and clinical-radiological profiles. Global cognition and education levels were lower in the amnestic iNPH group. We found no association between AD biomarkers and memory performances (total tau: β= –4.50; 95% CI [–11.96;2.96]; p = 0.236; amyloid-β (1–42): β= 8.60, 95% CI [–6.30;23.50]; p = 0.240). At baseline, amnestic iNPH patients performed worse on executive functions, attention, and gait speed but improved similarly to the non-amnestic iNPH patients after the tap test. Conclusions: In our clinical sample of iNPH patients, we confirm the lack of specificity of the amnestic profile for predicting AD pathology. Clinicians should not preclude amnestic iNPH patients from undergoing an invasive procedure of CSF derivation. [ABSTRACT FROM AUTHOR]

Despite bilateral hippocampal damage dating to the perinatal or early childhood period and severely impaired episodic memory, patients with developmental amnesia continue to exhibit well‐developed semantic memory across the developmental trajectory. Detailed information on the extent and focality of brain damage in these patients is needed to hypothesize about the neural substrate that supports their remarkable capacity for encoding and retrieval of semantic memory. In particular, we need to assess whether the residual hippocampal tissue is involved in this preservation, or whether the surrounding cortical areas reorganize to rescue aspects of these critical cognitive memory processes after early injury. We used voxel‐based morphometry (VBM) analysis, automatic (FreeSurfer) and manual segmentation to characterize structural changes in the brain of an exceptionally large cohort of 23 patients with developmental amnesia in comparison with 32 control subjects. Both the VBM and the FreeSurfer analyses revealed severe structural alterations in the hippocampus and thalamus of patients with developmental amnesia. Milder damage was found in the amygdala, caudate, and parahippocampal gyrus. Manual segmentation demonstrated differences in the degree of atrophy of the hippocampal subregions in patients. The level of atrophy in CA‐DG subregions and subicular complex was more than 40%, while the atrophy of the uncus was moderate (−24%). Anatomo‐functional correlations were observed between the volumes of residual hippocampal subregions in patients and selective aspects of their cognitive performance, viz, intelligence, working memory, and verbal and visuospatial recall. Our findings suggest that in patients with developmental amnesia, cognitive processing is compromised as a function of the extent of atrophy in hippocampal subregions. More severe hippocampal damage may be more likely to promote structural and/or functional reorganization in areas connected to the hippocampus. In this hypothesis, different levels of hippocampal function may be rescued following this variable reorganization. Our findings document not only the extent, but also the limits of circuit reorganization occurring in the young brain after early bilateral hippocampal damage. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

This paper tackles the issue of the diversity of déjà experiences. According to the standard view in the neuropsychological literature, they should all be defined by means of a psychological criterion, by which they are experiences triggered by a perceived item and consist of a conscious clash between a first-order feeling of familiarity about the item and a second-order evaluation that assesses the first-order feeling as erroneous. This paper dismisses the standard view and contends there are two types of déjà experiences, labeled déjà vu and déjà vécu respectively. But it also takes issue with the rare proponents of a distinct déjà vécu type. Contrary to their achievement view, it argues that recollection is not involved in déjà vécu experiences as an actual mental state or a component thereof. In our ability view, déjà vécu involves the feeling that one could recollect past occurrences of a currently lived episode of experience. [ABSTRACT FROM AUTHOR]

Although the role of the medial temporal lobe (MTL) and the hippocampus in episodic memory is well established, there is emerging evidence that these regions play a broader role in cognition, specifically in temporal processing. However, despite strong evidence that the hippocampus plays a critical role in sequential processing, the involvement of the MTL in timing per se is poorly understood. In the present study, we investigated whether patients with MTL damage exhibit differential performance on a temporal distance memory task. Critically, we manipulated context shifts, or boundaries, which have been shown to interfere with associative binding, leading to increases in subjective temporal distance. We predicted that patients with MTL damage would show impaired binding across boundaries and thus fail to show temporal expansion. Consistent with this hypothesis, unilateral patients failed to show a temporal expansion effect, and bilateral patients actually exhibited the reverse effect, suggesting a critical role for the MTL in binding temporal information across boundaries. Furthermore, patients were impaired overall on both the temporal distance memory task and recognition memory, but not on an independent, short-timescale temporal perception task. Interestingly, temporal distance performance could be independently predicted by performance on recognition memory and the short temporal perception task. Together, these data suggest that distinct mnemonic and temporal processes may influence long interval temporal memory and that damage to the MTL may impair the ability to integrate episodic and temporal information in memory. [ABSTRACT FROM AUTHOR]