Contextual Memory Research Articles

Collective memory and trans history in the Italian context: Archival practices and the creation of the first trans archive in Italy

In recent years, there has been a growing scholarly interest in the relationship between history, memory, archiving and trans experiences. This body of work has shown how questioning the praxis of archiving from the vantage point of trans experiences has the potential to problematise cis-heteronormative assumptions around the body, time and space and to queer the epistemological premises around what constitutes archives and archival practices. In this article, we present the experience of the project ArchiviST* – Archivi Storia Trans (Trans History Archives) which aims to create the first archive exclusively dedicated to the history of trans lives and activism in contemporary Italy. The project has been promoted by Trans Identity Movement, the most influential and long-lived trans association in Italy. Since its birth in 1979, Trans Identity Movement informally collected a substantial documentary heritage concerning trans and LGBTQIA+ history as a political practice to preserve the counter-memories of its people and movements. The ArchiviST* project carries out the inventorying and digitising of the materials, together with the collection of original video-recorded interviews with pioneering activists of the trans movement. By presenting a reflection on the process of ‘reconstructing’ an archive in this context, we unpack and explore some of the key issues surrounding trans archiving and collective memories in the Italian context: what counts as collective memory? What types of relationships are established between trans memories and the documents present in the archive? What memories have (not) been told, and what voices and subjects have (not) emerged as protagonists? We encourage a reflexive attitude towards the practice of trans archiving to problematise established historiographical categories, such as time, private/public, political engagement, life history and memory and to recognise the ethical and methodological challenges that such a path poses to historiography and archive research in general.

Infants use contextual memory to attend and learn in naturalistic scenes.

Infants encounter new objects and learn about object features in relation to a rich and detailed visuospatial context. Using a contextual cueing task, recent work showed that 6- and 10-month-old infants search more efficiently for target objects in repeated rather than novel visuospatial contexts (i.e., arrays of shapes on a blank background). Here, we investigate whether infants' sensitivity to visuospatial context scales up to more complex and potentially more distracting, naturalistic scenes. In an eye-tracking task, 8-month-olds searched for a novel target object in colorful photographs of everyday environments (e.g., bedrooms and kitchens). Repeated ("Old") contexts co-varied with target locations, such that the target object appeared in exactly the same location on the same scene, while varying ("New") contexts contained target objects placed in different counterbalanced locations across a variety of scenes. Infants exhibited faster search times, more anticipation of target animation, and longer looking at targets that appeared in Old relative to New contexts. In a subsequent memory test, infants showed better recognition of label-object pairings for target objects that had appeared in Old, rather than New, contexts. These results indicate that infants can use visuospatial contextual information in complex naturalistic scenes to facilitate memory-guided attention and learning of object-paired labels.

Striatal μ-opioid receptor activation triggers direct-pathway GABAergic plasticity and induces negative affect.

Withdrawal from chronic opioid use often causes hypodopaminergic states and negative affect, which may drive relapse. Direct-pathway medium spiny neurons (dMSNs) in the striatal patch compartment contain μ-opioid receptors (MORs). It remains unclear how chronic opioid exposure and withdrawal impact these MOR-expressing dMSNs and their outputs. Here, we report that MOR activation acutely suppressed GABAergic striatopallidal transmission in habenula-projecting globus pallidus neurons. Notably, withdrawal from repeated morphine or fentanyl administration potentiated this GABAergic transmission. Furthermore, intravenous fentanyl self-administration enhanced GABAergic striatonigral transmission and reduced midbrain dopaminergic activity. Fentanyl-activated striatal neurons mediated contextual memory retrieval required for conditioned place preference tests. Importantly, chemogenetic inhibition of striatal MOR+ neurons rescued fentanyl withdrawal-induced physical symptoms and anxiety-like behaviors. These data suggest that chronic opioid use triggers GABAergic striatopallidal and striatonigral plasticity to induce a hypodopaminergic state, which may promote negative emotions and relapse.

Impaired cognitive performance in older adults is associated with deficits in item memory and memory for object features

Amnestic mild cognitive impairment (aMCI) is associated with damage to the perirhinal/entorhinal cortex, and consequently, deficits in item/object memory. However, cognitive assessments commonly used to identify individuals with aMCI require a clinician to administer and interpret the test. We developed a novel self-administered global cognitive assessment, called the Cognitive Assessment via Keyboard (CAKe). To assess the relationship between CAKe performance and perirhinal/entorhinal cortex-dependent memory function, participants completed the CAKe, a feature source memory task, and a context memory task. During the memory tasks, participants studied line drawings with either a green or orange internal color (feature memory runs) or external color (context memory runs) and then classified each item as old and previously presented with a “green” or “orange” color, or “new”. CAKe scores were correlated with item memory accuracies and source memory accuracies on both tasks. Participants with ‘impaired’ CAKe performance had worse item memory and worse feature source memory accuracies than those with ‘normal’ CAKe performance. These results demonstrate specific deficits in item memory and feature source memory and suggest that our assessments may be a valid predictor of aMCI memory deficits.

A Ventromedial Prefrontal-to-Lateral Entorhinal Cortex Pathway Modulates the Gain of Behavioral Responding During Threat

BackgroundThe ability to correctly associate cues and contexts with threat is critical for survival, and the inability to do so can result in threat-related disorders such as posttraumatic stress disorder. The prefrontal cortex (PFC) and hippocampus are well known to play critical roles in cued and contextual threat memory processing. However, the circuits that mediate prefrontal-hippocampal modulation of context discrimination during cued threat processing are less understood. Here, we demonstrate the role of a previously unexplored projection from the ventromedial region of PFC (vmPFC) to the lateral entorhinal cortex (LEC) in modulating the gain of behavior in response to contextual information during threat retrieval and encoding. MethodsWe used optogenetics followed by in vivo calcium imaging in male C57/B6J mice to manipulate and monitor vmPFC-LEC activity in response to threat-associated cues in different contexts. We then investigated the inputs to, and outputs from, vmPFC-LEC cells using Rabies tracing and channelrhodopsin-assisted electrophysiology. ResultsvmPFC-LEC cells flexibly and bidirectionally shaped behavior during threat expression, shaping sensitivity to contextual information to increase or decrease the gain of behavioral output in response to a threatening or neutral context, respectively. ConclusionsGlutamatergic vmPFC-LEC cells are key players in behavioral gain control in response to contextual information during threat processing and may provide a future target for intervention in threat-based disorders.

The Chaining Method for Better Vocabulary Retention: Tunisian University Students as a Case Study

A major current focus in vocabulary instruction has been on how to foster autonomous learning and provide learners with techniques to deal with vocabulary retention. In view of this idea, numerous studies have been interested in investigating the effect of teaching such mnemonic strategies on learners’ ability to retain new items. Thus, this paper intends to focus on the concept of the narrative chain method as a memory vocabulary learning strategy that helps EFL learners to remember new vocabulary. It, therefore, aims at shedding light on the importance of learners’ active role in practising the method, creating and imagining the storyline, and reflecting on it at the end of the process. To reach this purpose, fifty first-year Tunisian EFL university students were randomly selected to complete memory vocabulary strategy training. An evaluation checklist was then held to gain more information about their attitudes toward the technique’s efficiency. Qualitative results have provided positive feedback concerning the narrative chain method treatment. The findings of the current study have led to crucial contributions to vocabulary teaching practices that should display the close connection between the active vocabulary learning/retention process and long-term memory in the Tunisian context.

Competitive lieux de memoire in a post-socialist dark tourism context: an explorative study of a Slovenian case

ABSTRACT This study sheds light on competitive lieux de memoire in the south-east of Slovenia that are directly related to significant social changes of the twentieth century. The aim is to evaluate the perceptions of influential domestic stakeholders, including experts and media, representing (different) perspectives of the transformation of sites of memory into national and transnational spaces of memory in the dark tourism context. We carried out 10 interviews and a qualitative inductive content analysis, and a subsequent qualitative deductive content analysis of 16 news media articles. Creating an Euler diagram, we compared real social and media-created reality and found inconsistencies: only three main categories are common. We found that development issues are highlighted within social reality, while the media mainly report on what was observed on the ground, at sites or events. Despite the polarised Slovenian post-socialist atmosphere, competitive memories gradually become multidirectional with the potential for the commodification of lieux de memoire within international dark tourism.

Collective memory: Collaborative recall synchronizes what and how people remember.

Memory researchers and theorists have long advanced the idea that the manner in which information is retrieved is critical. The way retrieval unfolds provides critical insights into how memories are organized and accessed-an important aspect of memory missed by focusing only on quantity. Cognitive studies of memory in social contexts, deploying the collaborative memory paradigm, have also noted the importance of such retrieval organization. Such memory studies often focus on how relative to "groups" that never collaborated, former members of collaborating groups recall more of the same material (collective memory) and they do so in a more synchronized fashion (collective retrieval organization). In this review, we leverage the diverse methodological and quantitative toolkits that have traditionally targeted individual retrieval to highlight the ways in which this social memory research has examined collective memory and collective retrieval organization. To that end, we consider how the collaborative memory paradigm has integrated methods, such as free recall, that afford rich assessments of retrieval organization. Likewise, we consider the application of metrics that characterize organization patterns in different contexts. With this background in mind, we discuss the important theoretical and broader implications of research on collective memory and collective retrieval organization. This article is categorized under: Psychology > Memory.

The precuneus as a central node in declarative memory retrieval.

Both, the hippocampal formation and the neocortex are contributing to declarative memory, but their functional specialization remains unclear. We investigated the differential contribution of both memory systems during free recall of word lists. In total, 21 women and 17 men studied the same list but with the help of different encoding associations. Participants associated the words either sequentially with the previous word on the list, with spatial locations on a well-known path, or with unique autobiographical events. After intensive rehearsal, subjects recalled the words during functional magnetic resonance imaging (fMRI). Common activity to all three types of encoding associations was identified in the posterior parietal cortex, in particular in the precuneus. Additionally, when associating spatial or autobiographical material, retrosplenial cortex activity was elicited during word list recall, while hippocampal activity emerged only for autobiographically associated words. These findings support a general, critical function of the precuneus in episodic memory storage and retrieval. The encoding-retrieval repetitions during learning seem to have accelerated hippocampus-independence and lead to direct neocortical integration in the sequentially associated and spatially associated word list tasks. During recall of words associated with autobiographical memories, the hippocampus might add spatiotemporal information supporting detailed scenic and contextual memories.

The cortisol switch between vulnerability and resilience.

In concert with neuropeptides and transmitters, the end products of the hypothalamus-pituitary-adrenal (HPA) axis, the glucocorticoid hormones cortisol and corticosterone (CORT), promote resilience: i.e., the ability to cope with threats, adversity, and trauma. To exert this protective action, CORT activates mineralocorticoid receptors (MR) and glucocorticoid receptors (GR) that operate in a complementary manner -as an on/off switch- to coordinate circadian events, stress-coping, and adaptation. The evolutionary older limbic MR facilitates contextual memory retrieval and supports an on-switch in the selection of stress-coping styles at a low cost. The rise in circulating CORT concentration after stress subsequently activates a GR-mediated off-switch underlying recovery of homeostasis by providing the energy for restraining the primary stress reactions and promoting cognitive control over emotional reactivity. GR activation facilitates contextual memory storage of the experience to enable future stress-coping. Such complementary MR-GR-mediated actions involve rapid non-genomic and slower gene-mediated mechanisms; they are time-dependent, conditional, and sexually dimorphic, and depend on genetic background and prior experience. If coping fails, GR activation impairs cognitive control and promotes emotional arousal which eventually may compromise resilience. Such breakdown of resilience involves a transition to a chronic stress construct, where information processing is crashed; it leads to an imbalanced MR-GR switch and hence increased vulnerability. Novel MR-GR modulators are becoming available that may reset a dysregulated stress response system to reinstate the cognitive flexibility required for resilience.

Effects of intra-hippocampal corticosterone and sleep on consolidation of memories of aversive experience in rats

Formation and consolidation of memories for highly stressful (traumatic) events is a complex process that involves interplay between multiple memory systems and has implications for etiology and treatment of stress- and trauma-related disorders. Here we study effects of sleep/wake states and high intra-hippocampal corticosterone on consolidation of aversive contextual memories, as well as consolidation of association between auditory unpaired phasic background cues and fear response in rats. Animals were implanted with EEG and EMG electrodes for sleep assessment and cannulas for intra-hippocampal corticosterone application. They were familiarized to a “safe box” and then trained in a fear conditioning paradigm in a distinct “shock box” with a prominent unpaired phasic background auditory cue. Immediately after conditioning, animals received bilateral intra-hippocampal saline (1 μl) or corticosterone (10 ng in 1 μl) injection and were either allowed to sleep or were kept awake for a following two-hour consolidation period. Memory tests 24 h later revealed that the saline-injected animals that slept during consolidation had significantly stronger fear responses in the shock box compared to the safe box as well as increased fear response in response to the auditory cue. Lack of sleep during the consolidation period in saline injected animals led to generalization of the fear response to the safe context, while association between auditory cue and fear response was preserved. High intra-hippocampal corticosterone levels during memory consolidation led to generalization of fear response to the safe context, regardless of sleep/wake state, while enhancement of response to auditory cue was not observed. Our results show how manipulation of conditions during consolidation can lead to greatly variable memories for an aversive episode with distinct behavioral outcomes. Observed overgeneralization of fear to safe context and altered fear response to background phasic cue has implications for understanding etiology of pathological memory alternations in stress-related conditions e.g., in posttraumatic stress disorder in humans.

Moving Towards Centers: Re-Ranking With Attention and Memory for Re-Identification

Re-ranking utilizes contextual information to optimize the initial ranking list of person or vehicle re-identification (re-ID), which boosts the retrieval performance at post-processing steps. This paper proposes a re-ranking network to predict the correlations between the probe and top-ranked neighbor samples. Specifically, all the feature embeddings of query and gallery images are expanded and enhanced by a linear combination of their neighbors, with the correlation prediction serves as discriminative combination weights. The combination process is equivalent to moving independent embeddings toward the identity centers, improving cluster compactness. For correlation prediction, we first aggregate the contextual information for probes k-nearest neighbors via the Transformer encoder. Then, we distill and refine the probe-related features into the Contextual Memory cell via attention mechanism. Like humans that retrieve images by not only considering probe images but also memorizing the retrieved ones, the Contextual Memory produces multiview descriptions for each instance. Finally, the neighbors are reconstructed with features fetched from the Contextual Memory, and a binary classifier predicts their correlations with the probe. Experiments on six widely-used person and vehicle re-ID benchmarks demonstrate the effectiveness of the proposed method. Especially, our method surpasses the state-of-the-art re-ranking approaches on large-scale datasets by a significant margin, i.e., with an average 3.08% CMC@1 and 7.46% mAP improvements on VERI-Wild, MSMT17, and VehicleID datasets.

An Extended Spatiotemporal Contextual Learning and Memory Network Model for Hardware Implementation

A spatiotemporal contextual learning and memory network (STCLMN) model was proposed based on the hippocampal CA1 network using the difference equations suitable for digital computer simulations. However, the inherent capability of handling and processing of continuous-time asynchronous signals (spikes) cannot be fully employed in the STCLMN model. Furthermore, digital circuit implementation of the STCLMN is not suitable for real-time edge applications, wherein small size, low power consumption, and real-time learning capability are necessary. Therefore, this study extends the original STCLMN model using a set of differential equations to overcome the above problems encountered by STCLMN for asynchronous circuit implementation. The minimum accuracy required for a compact and low-power hardware implementation of the proposed model is then investigated. The validity and feasibility of the proposed model are confirmed through numerical simulations and experiments with a small mixed analog/digital circuit based on the investigated accuracy. In this study, LIF neurons are used because of their ease of circuit implementation. The proposed eSTCLMN model would enable an efficient circuit implementation of an asynchronous spiking neural network with spatiotemporal contextual one-shot learning and memory.

Tecnologias Digitais da Informação e Comunicação na Preservação da Memória e da Identidade Cultural de Comunidades Tradicionais

The present paper aimsto identify the use of Digital Technologies of Information and Communication –DTIC in the preservation of memory and cultural identity of traditional communities in the scientific productions of Information Science in Brazil. The methodology adopted is the Systematic Literature Review with qualitative approach, in which therewere researched journals indexed by the Reference Database of Journal Articles in Information Science (BRAPCI) published from 2016 to 2021. Therewere analyzed the journals which presented in the title, abstract and/or keywords themes about preservation of memory/identity related to the use of the DTIC/TIC and the traditional peoplesand communities of Brazil. The results point that therewere recovered few papersthat aretotally related to the preservation of memory, traditional communities and the use of DTIC/TIC. However, it was possible to note that the DTIC have been used with the purpose of preservation of memory in several contexts. Moreover, despite of the preservation of memory and cultural identity, the used DTIC still haveas a purpose the dissemination and visibility of these peoples, in order to require the due respect and the full exercise of their citizenship fromthe State and the Society.

Memory discrimination is promoted by the expression of the transcription repressor WT1 in the dentate gyrus.

The hippocampus is critical for the precise formation of contextual memories. Overlapping inputs coming from the entorhinal cortex are processed by the trisynaptic pathway to form distinct memories. Disruption in any step of the circuit flow can lead to a lack of memory precision, and to memory interference. We have identified the transcriptional repressor Wilm's Tumor 1 (WT1) as an important regulator of synaptic plasticity involved in memory discrimination in the hippocampus. In male mice, using viral and transgenic approaches, we showed that WT1 deletion in granule cells of the dentate gyrus (DG) disrupts memory discrimination. With electrophysiological methods, we then identified changes in granule cells' excitability and DG synaptic transmission indicating that WT1 knockdown in DG granule cells disrupts the inhibitory feedforward input from mossy fibers to CA3 by decreasing mIPSCs and shifting the normal excitatory/inhibitory (E/I) balance in the DG → CA3 circuit in favor of excitation. Finally, using a chemogenetic approach, we established a causal link between granule cell hyperexcitability and memory discrimination impairments. Our results suggest that WT1 enables a circuit-level computation that drives pattern discrimination behavior.

Olive Oil and Basketball: On Collective Memory and America’s Troubled Alliances with the Philippines and Thailand

United States’ alliances in Southeast Asia are troubled. This paper argues that dominant frameworks for understanding alliance dynamics, which assume that rational calculation and bargaining are the primary sources of alliance dynamics, are inadequate for explaining the fragility of US alliances with Thailand and the Philippines. It proposes that a constructivist perspective, emphasising identity, emotion, and collective memory, offers a useful supplementary lens for explaining why some alliances experience turbulence. The paper sets out the theoretical case for examining collective memory in an alliance context, together with a methodology for practical application. The paper finds that in the US-Thai alliance, the domestic politics of collective memory has constrained commemoration of highpoints in the longstanding US-Thai military partnership, leaving the alliance with weaker public support and more vulnerable to strains than would otherwise have been the case. In the Philippines, state sanctioned narratives recognising shared sacrifice during the Second World War are counterbalanced by traumatic memories of the United States-Philippines colonial war, producing a deep ambivalence. These results point to the need for more systematic analysis of collective memory as an important variable in international politics.

Neocortical synaptic engrams for remote contextual memories

While initial encoding of contextual memories involves the strengthening of hippocampal circuits, these memories progressively mature to stabilized forms in neocortex and become less hippocampus dependent. Although it has been proposed that long-term storage of contextual memories may involve enduring synaptic changes in neocortical circuits, synaptic substrates of remote contextual memories have been elusive. Here we demonstrate that the consolidation of remote contextual fear memories in mice correlated with progressive strengthening of excitatory connections between prefrontal cortical (PFC) engram neurons active during learning and reactivated during remote memory recall, whereas the extinction of remote memories weakened those synapses. This synapse-specific plasticity was CREB-dependent and required sustained hippocampal signals, which the retrosplenial cortex could convey to PFC. Moreover, PFC engram neurons were strongly connected to other PFC neurons recruited during remote memory recall. Our study suggests that progressive and synapse-specific strengthening of PFC circuits can contribute to long-term storage of contextual memories.

Increased histone acetylation levels or a serotonin precursor reinstate the context memory impaired by the serotonin receptor blocker methiothepin

Increased histone acetylation levels or a serotonin precursor reinstate the context memory impaired by the serotonin receptor blocker methiothepin

A search pattern for the engram.

Roy and colleagues (Nature Communications, 13.1, 1-16, 2022) examined neuronal ensembles associated with contextual fear conditioning memory across multiple brain regions, referred to as a unified engram complex. Their four-step approach incorporating brain-wide mapping of activated neurons, engram indexing, and optogenetic and chemogenetic manipulations could offer a novel, holistic approach to implement in our continued search for the engram.

Selective Menin Deletion in the Hippocampal CA1 Region Leads to Disruption of Contextual Memory in the MEN1 Conditional Knockout Mouse: Behavioral Restoration and Gain of Function following the Reintroduction of MEN1 Gene.

Cholinergic neuronal networks in the hippocampus play a key role in the regulation of learning and memory in mammals. Perturbations of these networks, in turn, underlie neurodegenerative diseases. However, the mechanisms remain largely undefined. We have recently demonstrated that an in vitro MEN1 gene deletion perturbs nicotinic cholinergic plasticity at the hippocampal glutamatergic synapses. Furthermore, MEN1 neuronal conditional knockout in freely behaving animals has also been shown to result in learning and memory deficits, though the evidence remains equivocal. In this study, using an AVV viral vector transcription approach, we provide direct evidence that MEN1 gene deletion in the CA1 region of the hippocampus indeed leads to contextual fear conditioning deficits in conditional knockout animals. This loss of function was, however, recovered when the same animals were re-injected to overexpress MEN1. This study provides the first direct evidence for the sufficiency and necessity of MEN1 in fear conditioning, and further endorses the role of menin in the regulation of cholinergic synaptic machinery in the hippocampus. These data underscore the importance of further exploring and revisiting the cholinergic hypothesis that underlies neurodegenerative diseases that affect learning and memory.