Memory Content Research Articles

Ukrainian testimonial-based comics in the mediatised space of war

ABSTRACT The article presents various strategies of temporality and documentation created by Ukrainian comic books during the war. The first stage of the war (2014–2021) updated the heroic narrative of military comics – the Kiborhy series and recreated the stories of victims and eyewitnesses (the graphic novel Crossroads: nine stories about war and violence). There was an emphasis on the destigmatisation of the tragic battle experience in war and social comics, reports and autobiographies. The intense mediatisation of the war after the full-scale invasion made it the most documented in history, with a powerful content of digital memories, life stories, testimonies of war crimes, interviews and recollections. The graphic reproduction of everyday wartime life is created in the new conditions of the chronotope – here and now – in an effort not to forget and lose, to leave a memory and a remembrance of life, deeds and death (web-magazine Inker). Comics respond to the events of war, trying to capture a fleeting sense of presence and emotional involvement, to reproduce the ‘voices of war’ in graphic language, to visualise the real stories of the living and to immortalise the deeds of the fallen. This combination of documentation, memorialisation and memory makes the experience of Ukrainian comics during the war unique.

Effect of exogenous β-hydroxybutyrate on BDNF signaling, cognition, and amyloid precursor protein processing in humans with T2D and insulin-resistant rodents.

People with type 2 diabetes (T2D) have a greater risk of developing neurodegenerative diseases, like Alzheimer's disease, in later life. Exogenous ketone supplements containing the ketone body β-hydroxybutyrate (β-OHB) may be a strategy to protect the brain as β-OHB can support cerebral metabolism and promote neuronal plasticity via expression of brain-derived neurotrophic factor (BDNF). Parallel human (ClinicalTrials.gov ID NCT04194450, ClinicalTrials.gov ID NCT05155410) and rodent trials were conducted to characterize the effect of acute and short-term exogenous ketone supplementation on indices of brain health. First, we aimed to investigate the effect of acute and short-term supplementation of exogenous ketone monoester on circulating BDNF and cognition in adults with T2D. There were no effects of ketone supplementation on plasma BDNF or cognition. Second, we aimed to investigate the mechanistic effects of acute and chronic β-OHB supplementation on cortical BDNF content and recognition memory in C57BL/6J mice with and without insulin resistance. Acutely, β-OHB did not alter recognition memory or BDNF content. Similarly, chronic β-OHB supplementation did not alter recognition memory or BDNF content. Collectively, our data demonstrates that ketone supplementation does not elevate BDNF content in humans or mice. Furthermore, our data does not support the involvement of BDNF in the potential cognitive benefits of β-OHB supplementation.NEW & NOTEWORTHY Ketone supplementation does not alter circulating BDNF levels or cognition in humans with T2D. Acute and chronic ketone supplementation in C57BL/6J mice did not change BDNF protein content or improve recognition memory. Ketone supplementation in C57BL/6J mice positively modulated β-site amyloid precursor protein cleaving enzyme 1 (BACE1) activity, providing a potential future therapeutic strategy.

The cognitive and emotional content of music-evoked autobiographical memories in older adults

The cognitive and emotional content of music-evoked autobiographical memories in older adults

Active noise cancellation using hybrid CNN-LSTM classification and genetic algorithm-based community detection extraction with LMS noise filtering process

Unwanted signals in information-bearing signal referred to as noise could degrade the strength of signals in terms of intelligibility and quality. Over the decade, various researchers developed algorithms to enhance speech signal quality and noise reduction. To address the issue, the study propounded the active noise cancellation method by using a hybridized convolutional neural network–long short-term memory (CNN-LSTM) approach and genetic algorithm (GA)-based community detection feature extraction enhanced with least mean square (LMS) noise filtering process. The quality filtered signals were extracted with feature correlation data and precise relevant features using genetic algorithm-based community detection. The selective parameters aid the classification performance, facilitated by hyperparameter fine-tuning of GA-based community detection. The results of incorporating LSTM will eliminate unnecessary memory content by correlating past information outcomes to classify new feature values. In this method, abnormal and normal signals are classified by our LSTM layers output. These classified outcomes aid in the denoise of active voice signals with a fast convergence rate. The efficiency of the proposed method was assessed in terms of its performance through comparative active noise cancellation (ANC) methods. The higher accuracy rate and low NMSE in the classification of audio signals evidenced the efficacy of the proposed ANC model.

On classifying memory contents at page-level granularity: machine-learning approach

On classifying memory contents at page-level granularity: machine-learning approach

Войны памяти и война с памятью, мемориальный суверенитет: подходы, концепции, разработки

The purpose of this article is to generalize the problems of socio-historical memory based on the material of social philosophy, as well as to attempt a balanced assessment of the current situation and strategies for preserving the genetic foundations of Russian culture. The research methodology is based on the idea of the complexity of open social systems and on a theoretical analysis of politico-sociological and socio-philosophical literature. A socio-philosophical interpretation of the conceptual distinction between social and historical memory is provided. Further, the paper describes the fundamental features of sociohistorical memory, which originates in the mechanism of reproduction of the genetic foundations of culture on the one hand, and in the specifics of the social structure of society on the other. The results of the study demonstrate that historical and social memory are inextricably linked, acting in relation to each other, firstly, as the content of memory, and secondly, as a way of organizing it, i.e. storing and broadcasting its content. In addition, the paper presents a brief overview of the current socio-philosophical issues of various aspects of sociohistorical memory and identifies the key modern actors of social memory and the problems of their interaction: memorial groups, memorial legislation, memory wars and the war on memory, as well as dilemmas about the understanding of the nature of conflict between various memory systems based on different value foundations. The authors note that historical memory is faced with challenges, overcoming which it undergoes a significant transformation by getting involved in the agenda of modern digital communication associated with a variety of new information phenomena that emerge due to the nature of the Internet. Taking into account the new conditions for socio-historical memory in Russia, the authors point out the vulnerability of classical methods of preserving and broadcasting memory. Thus, studying the experience of memory preservation and its adaptation to the new conditions of disseminating information becomes relevant. The authors conclude by outlining ways to solve the aforementioned problems.

Working memory updating in the macaque lateral prefrontal cortex.

Working memory updating is an important executive process. Here, we study the single-neuron mechanisms involved in updating versus protecting memory from distractors in the macaque prefrontal cortex. We recorded single-neuron activity from the lateral prefrontal cortex (LPFC) and prearcuate cortex (PAC) while male monkeys performed a task that required them to update their memory of target locations while ignoring distractors. Our findings revealed that neurons in the PAC signaled updated memory locations approximately ∼100 ms after stimulus onset, significantly faster than the ∼400 ms observed in the LPFC. Additionally, PAC neurons exhibited longer encoding of distractor information. Population decoding analyses further indicated that distractor information was maintained in orthogonal subspaces from target information in both regions, minimizing interference. These results demonstrate the distinct temporal dynamics in memory updating processes between the PAC and LPFC and highlight the interplay between robust memory maintenance and updating, suggesting that local neural mechanisms may contribute to these processes.Significance Statement Working memory is a fundamental cognitive function. It stored information in the short term, and this information can be manipulated to allow intelligent behaviors. The lateral prefrontal cortex is involved in this process, but the mechanisms of working memory manipulation remain unclear. Here, we studied one type of manipulation; working memory updating, which refers to the exchange of one memory for another. We found that two adjacent regions in the lateral prefrontal cortex show different updating times: while a posterior region updates memory content very fast, the more anterior region takes significantly longer. These results show that working memory updating may involve multiple operations, such as updating of memory or attention versus updating of motor plans.

Competing working memory contents: perceptual over semantic prioritization and voluntary retrieval following retro-cueing

ABSTRACT This study investigated how voluntary and involuntary retrospective attention prioritize working memory (WM) representations of low-level visual features (perceptual dimension) and high-level categories (semantic dimension) using real-world objects. Reaction time and accuracy from two retro-cueing experiments were analyzed with a hierarchical drift-diffusion model to assess impacts on representation quality (drift rate) and retrieval time (non-decision time). Voluntariness of attention did not differentially affect perceptual and semantic WM contents. Drift rates showed stronger retro-cueing effects on perceptual compared to semantic contents, while non-decision times revealed retro-cueing effects only for voluntary attention. These findings suggest: (1) voluntariness does not differentiate between perceptual and semantic contents competing in WM; (2) attention prioritizes perceptual over semantic contents; and (3) voluntariness is critical for retrieving WM contents in advance of decision-making. This work highlights how WM content type and attentional voluntariness independently shape the effects of retrospective attention.

The virtual habits underlying the behavioural hallmarks of alloanimal episodic memory: a Peircean model

Abstract Experimental studies of animal episodic memory test the behavioural expression of a what-where-when ‘memory content’. This is to say, autobiographical memory in some species (mainly birds, rodents, and great apes) has been understood on the basis of how the subject’s actions demonstrate their long-term awareness of already enacted and yet-to-be enacted scenarios. However, such behavioural focus has come at the expense of discussing the interdependent role of two equally important episodic hallmarks: ‘memory structure’ (mental representations), and ‘memory flexibility’ (adaptive choice-making). This paper provides a semiotic characterization of those less discussed hallmarks, in terms of the Peircean concept of virtual habit or the mental enactment of non-present episodes. It is argued that the behavioural expression of a ‘memory content’ (as object in a process of semiosis) cannot be accounted for without understanding the phenomenological or experiential support of memory structure (as a representamen), and the teleological or purposeful self-control of memory flexibility (as interpretant). Based on this, a new cognitive model of animal episodic memory is proposed, consisting of interrelated modalities called Virtualiter, Habitualiter, and Actualiter. Capitalizing on multispecies evidence, possible applications and new directions of the model are suggested.

Time-Dependent Transcriptional Dynamics of Contextual Fear Memory Retrieval Reveals the Function of Dipeptidyl Peptidase 9 in Reconsolidation

Numerous studies on the formation and consolidation of memory have shown that memory processes are characterized by phase-dependent and dynamic regulation. Memory retrieval, as the only representation of memory content and an active form of memory processing that induces memory reconsolidation, has attracted increasing attention in recent years. Although the molecular mechanisms specific to memory retrieval-induced reconsolidation have been gradually revealed, an understanding of the time-dependent regulatory mechanisms of this process is still lacking. In this study, we applied a transcriptome analysis of memory retrieval at different time points in the recent memory stage. Differential expression analysis and Short Time-series Expression Miner (STEM) depicting temporal gene expression patterns indicated that most differential gene expression occurred at 48 h, and the STEM cluster showing the greatest transcriptional upregulation at 48 h demonstrated the most significant difference. We then screened the differentially-expressed genes associated with that met the expression patterns of those cluster-identified genes that have been reported to be involved in learning and memory processes in addition to dipeptidyl peptidase 9 (DPP9). Further quantitative polymerase chain reaction verification and pharmacological intervention suggested that DPP9 is involved in 48-h fear memory retrieval and viral vector-mediated overexpression of DPP9 countered the 48-h retrieval-induced attenuation of fear memory. Taken together, our findings suggest that temporal gene expression patterns are induced by recent memory retrieval and provide hitherto undocumented evidence of the role of DPP9 in the retrieval-induced reconsolidation of fear memory.

Attention-Driven Memory Network for Online Visual Tracking.

A memory mechanism has attracted growing popularity in tracking tasks due to the ability of learning long-term-dependent information. However, it is very challenging for existing memory modules to provide the intrinsic attribute information of the target to the tracker in complex scenes. In this article, by considering the biological visual memory mechanisms, we propose the novel online tracking method via an attention-driven memory network, which can mine discriminative memory information and enhance the robustness and reliability of the tracker. First, to reinforce effectiveness of memory content, we design a novel attention-driven memory network. In the network, the long memory module gains property-level memory information by focusing on the state of the target at both the channel and spatial levels. Meanwhile, in reciprocity, we add a short-term memory module to maintain good adaptability when confronting drastic deformation of the target. The attention-driven memory network can adaptively adjust the contribution of short-term and long-term memories to tracking results under the weighted gradient harmonized loss. On this basis, to avoid model performance degradation, an online memory updater (MU) is further proposed. It is designed to mining for target information in tracking results through the Mixer layer and the online head network together. By evaluating the confidence of the tracking results, the memory updater can accurately judge the time of updating the model, which guarantees the effectiveness of online memory updates. Finally, the proposed method performs favorably and has been extensively validated on several benchmark datasets, including object tracking benchmark-50/100 (OTB-50/100), temple color-128 (TC-128), unmanned aerial vehicles-123 (UAV-123), generic object tracking -10k (GOT-10k), visual object tracking-2016 (VOT-2016), and VOT-2018 against several advanced methods.

Struggles over memory?

AbstractIn this contribution, I introduce decolonial memory activism as struggle over meaning (Deutungskampf). Decolonial memory activism is understood as a specific form of memory activism that calls for the decolonization of both memory culture and politics, which necessitates a confrontation with dynamics of violence, power, and oppression. Unlike research that has primarily focused on the contents of collective memory, I argue that decolonial memory activism seeks to fundamentally challenge and transform the epistemological foundations of collective memory itself. Grounded in decolonial theories and drawing from a shared resolution of decolonial memory activists across Germany, I illustrate three interwoven elements of hegemonic knowledge that are being challenged by decolonial memory activism: nationalism, temporality, and the storage model of memory. Through this lens, the paper suggests that an understanding of struggles over memory gains more depth by considering the epistemic dimensions of these struggles. Such an approach opens up new possibilities for peace and conflict research as well as for social and political transformations.

Acts of Remembering: From a Radically Enactive Point of View

ABSTRACT Cognitivists and radically enactivists understand acts of remembering in fundamentally different ways. It is a hallmark of cognitivism to seek to identify some independent component that puts the memory – the what’s remembered – into acts of remembering. Such a component is variably characterized as: a stored memory, a stored content, or stored information. Accordingly, and on this basis, cognitivists seek to distinguish memories from acts of remembering. This paper raises doubts about the very idea that we can make sense of the real, independent existence of stored memory contents or stored memory information and, in its place, motivates adoption of a radically enactivist approach to understanding various acts of remembering.

Adaptive memory reservation strategy for heavy workloads in the Spark environment.

The rise of the Internet of Things (IoT) and Industry 2.0 has spurred a growing need for extensive data computing, and Spark emerged as a promising Big Data platform, attributed to its distributed in-memory computing capabilities. However, practical heavy workloads often lead to memory bottleneck issues in the Spark platform. This results in resilient distributed datasets (RDD) eviction and, in extreme cases, violent memory contentions, causing a significant degradation in Spark computational efficiency. To tackle this issue, we propose an adaptive memory reservation (AMR) strategy in this article, specifically designed for heavy workloads in the Spark environment. Specifically, we model optimal task parallelism by minimizing the disparity between the number of tasks completed without blocking and the number completed in regular rounds. Optimal memory for task parallelism is determined to establish an efficient execution memory space for computational parallelism. Subsequently, through adaptive execution memory reservation and dynamic adjustments, such as compression or expansion based on task progress, the strategy ensures dynamic task parallelism in the Spark parallel computing process. Considering the cost of RDD cache location and real-time memory space usage, we select suitable storage locations for different RDD types to alleviate execution memory pressure. Finally, we conduct extensive laboratory experiments to validate the effectiveness of AMR. Results indicate that, compared to existing memory management solutions, AMR reduces the execution time by approximately 46.8%.

Going through the motions: Biasing of dynamic attentional templates.

Attention must coordinate with memory to actively anticipate sensory input and guide action. Memory content may be biased away from veridical when it is functionally adaptive. So far, research has considered the biasing of still features in static displays. It is unknown whether the biasing of attentional templates can functionally adapt dynamic stimuli to facilitate search when targets and distractors compete within temporally extended contexts. Biasing of dynamic templates would require learning and modulatory mechanisms capable of abstracting over space and time to guide perception. Four experiments used a novel dynamic visual search task combined with a memory probe to test whether dynamic attentional templates can be biased. In Experiments 1-3, participants searched for a moving target among distractors that systematically moved either clockwise or counterclockwise relative to the target. On memory probe trials, participants recalled the target direction as biased away from the distractors. The distortion bias was adaptively changed (Experiment 2), grew over time (Experiment 2), and occurred even when motion direction was not the target-defining feature (Experiment 3). Experiment 4 manipulated the speed of targets and distractors to test the generalizability of the findings. Participants searched for a target of a given speed among faster or slower distractors. Memory probing revealed that participants remembered the target speed as biased away from that of distractors. Across different tasks, the magnitude of the biasing correlated positively with search performance. Our findings provide compelling evidence that dynamic stimulus attributes in attentional templates can become functionally biased when adaptive. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Goal Shifts Structure Memories and Prioritize Event-defining Information in Memory.

Every day, we encounter far more information than we could possibly remember. Thus, our memory systems must organize and prioritize the details from an experience that can adaptively guide the storage and retrieval of specific episodic events. Prior work has shown that shifts in internal goal states can function as event boundaries, chunking experiences into distinct and memorable episodes. In addition, at short delays, memory for contextual information at boundaries has been shown to be enhanced compared with items within each event. However, it remains unclear if these memory enhancements are limited to features that signal a meaningful transition between events. To determine how changes in dynamic goal states influence the organization and content of long-term memory, we designed a 2-day experiment in which participants viewed a series of black-and-white objects surrounded by a color border on a two-by-two grid. The location of the object on the grid determined which of two tasks participants performed on a given trial. To examine if distinct types of goal shifts modulate the effects of event segmentation, we changed the border color, the task, or both after every four items in a sequence. We found that goal shifts influenced temporal memory in a manner consistent with the formation of distinct events. However, for subjective memory representations in particular, these effects differed by the type of event boundary. Furthermore, to examine if goal shifts lead to the prioritization of goal-relevant features in longer lasting memories, we tested source memory for each object's color and grid location both immediately and after a 24-hr delay. On the immediate test, boundaries enhanced the memory for all concurrent source features compared with nonboundary items, but only if those boundaries involved a goal shift. In contrast, after a delay, the source memory was selectively enhanced for the feature relevant to the goal shift. These findings suggest that goals can adaptively structure memories by prioritizing contextual features that define a unique episode in memory.

Attentional Refreshing in Working Memory and Its Interplay with Long-term Memory: A Behavioral and EEG Study.

Despite the growing interest in the study of attentional refreshing, the functioning of this working memory maintenance mechanism, including its cerebral underpinnings, is still debated. In particular, it remains unclear whether refreshing promotes long-term memory and whether it, in return, depends on long-term memory content to operate. Here, we used direct maintenance instructions and measured brain activity to investigate working memory maintenance with two objectives: (1) test if different behavioral and oscillatory patterns could be observed when participants were instructed to use attentional refreshing versus verbal rehearsal, and (2) observe whether and how refreshing is modulated when maintaining novel (pseudowords) versus familiar (words) memoranda. We conducted an EEG experiment using a modified Brown-Peterson task, in which we manipulated the type of maintenance engaged through explicit instructions (verbal rehearsal vs. refreshing), the type of memoranda (words vs. pseudowords), and the memory load (2 vs. 6). Using scalp EEG, we measured both neural oscillations during working memory maintenance and ERPs during the concurrent parity judgment task. For words, we showed that verbal rehearsal benefited more short-term recall whereas refreshing benefited more delayed recall. In keeping with these behavioral differences between maintenance instructions, frontal-midline theta power increased with memory load only when using verbal rehearsal, whereas occipito-parietal alpha desynchronization was larger with refreshing than verbal rehearsal. When maintaining pseudowords, verbal rehearsal also benefitted short-term recall more than refreshing. However, no long-term memory benefit of refreshing was observed for pseudowords, and oscillatory activity was not different under the two maintenance instructions. Our results provide new evidence supporting the independence between attentional refreshing and verbal rehearsal, and bring new insight into refreshing functioning. We discuss the possible interpretations of these results and the implications for the attentional refreshing literature.

No evidence that visual impulses enhance the readout of retrieved long-term memory contents from EEG activity

Abstract The application of multivariate pattern analysis (MVPA) to electroencephalography (EEG) data allows neuroscientists to track neural representations at temporally fine-grained scales. This approach has been leveraged to study the locus and evolution of long-term memory contents in the brain, but a limiting factor is that decoding performance remains low. A key reason for this is that processes such as encoding and retrieval are intrinsically dynamic across trials and participants, and this runs in tension with MVPA and other techniques that rely on consistently unfolding neural codes to generate predictions about memory contents. The presentation of visually perturbing stimuli may experimentally regularize brain dynamics, making neural codes more stable across measurements to enhance representational readouts. Such enhancements, which have repeatedly been demonstrated in working memory contexts, could offer a tool to improve decoding in long-term memory tasks. In this study, we evaluated whether visual perturbations—or pings—improve our ability to predict the category of retrieved images from EEG activity during cued recall. Overall, our findings suggest that while pings evoked a prominent neural response, they did not reliably produce improvements in MVPA-based classification across several analyses. We discuss possibilities that could explain these results, including the role of experimental and analysis parameter choices and mechanistic differences between working and long-term memory.

Discrimination of mnemonic similarity is associated with short-term and long-term memory precision.

Remembering specific memories with precision relies on the differentiation of similar memory contents - a process commonly referred to as pattern separation and behaviorally operationalized as lure discrimination in the mnemonic similarity task. Although pattern separation is typically investigated in the context of long-term memory (LTM), recent research extends these findings to short-term memory (STM) within a mixture model framework, emphasizing the distinction between memory quality and quantity. According to this framework, pattern separation is associated with memory precision across STM and LTM, regardless of the overall memory likelihood. However, these associations among memory quality measures may persist without the mixture model assumption. In an alternative model, a unitary memory strength measure quantified as a discrimination score (d') may also capture the association between pattern separation and memory quality, as pattern separation has been previously linked with strength-based memory performance. We tested these possibilities based on individual differences among 132 participants who underwent tasks measuring mnemonic pattern separation and STM/LTM quality. We found that behavioral estimates of pattern separation are significantly correlated with STM and LTM precision, irrespective of the likelihood of STM/LTM recall success. However, these associations are absent when considering the correlation between pattern separation and memory strength under a unitary model framework. By leveraging individual differences to constrain our understanding of cognitive models, our data unravel the intricate relationship between pattern separation and memory quality across timescales. These findings may therefore contribute to identifying sensitive behavioral measures for detecting subtle memory deficits in older adults or clinical populations.

Active maintenance of working memory contents affects functioning of attentional filtering.

Salient objects are well known to capture attention. Furthermore, a stimulus associated with the attention-capturing objects could infiltrate into working memory. This was recently formulated as filter disruption theory. In the present study, we asked whether such disruption of filter and incidental encoding of irrelevant information into working memory could be prevented. We hypothesized that an active maintenance of information could activate top-down control, thereby preventing the incidental infiltration of irrelevant information into working memory. In experiments, participants performed two consecutive visual searches while maintaining a visual item in working memory. In the first search, one of nontarget items was associated with a salient distractor. Importantly, the color of the nontarget item related to the salient distractor was incidentally encoded into working memory, exerting memory-driven attentional capture in the second search. However, such incidental encoding of irrelevant information into working memory did not occur when participants had to maintain a single color in working memory. This provides novel evidence that while the attentional filter is subject to perceptual distraction, active maintenance of information in working memory can prevent such disruption of the filter.