Memory Research Articles

Hepatitis B virus-specific human stem cell memory T cells differentiate into cytotoxic T cells and eradicate HBV-infected hepatocytes in mice.

Chronic infection with the hepatitis B virus (HBV) induces progressive hepatic impairment. Achieving complete eradication of the virus remains a formidable challenge. Cytotoxic T lymphocytes, specific to viral antigens, either exhibit a numerical deficiency or succumb to an exhausted state in individuals chronically afflicted with HBV. The comprehension of the genesis and dissemination of stem cell memory T cells (TSCMs) targeting HBV remains inadequately elucidated. We identified TSCMs in subjects with chronic HBV infection and scrutinized their efficacy in a murine model with human hepatocyte transplants, specifically the TK-NOG mice. TSCMs were discerned in all subjects under examination. Introduction of TSCMs into the HBV mouse model precipitated a severe necro-inflammatory response, resulting in the elimination of human hepatocytes. TSCMs may constitute a valuable tool in the pursuit of a remedial therapy for HBV infection.

Percentage of using formulaic language in media discourseA comparison between the visual media and the written press

the language we use daily; A product of society, but each of us embodies it in his  way. Therefore, the speaker produces the language, but there is another aspect of the language, which is ready-made linguistic pieces, used directly by the individual owned by the linguistic group. Formulaic language is a general term for ready-made phrases in the language that have previously been produced and stored in human memory. This language usually has a fixed grammatical formula and a special meaning according to the situation and context in which it is presented. The use of this language leads to the coordination of sentences in the process of writing and communication, as well as adopting the eloquence of the sender and can influence the recipient more and convince him of his ideas, as well as help in logical intentions, automatic translation, and smart answers. This research, titled "Percentage of using formulaic language in media discourse: A comparison between the visual media and the written press", sheds light on the intensity of the formal language in the visual media and the written press. In the beginning, the formulaic language was explained, and then its use in the Kurdish media was explained. The importance of research in linking the media discourse with  formal language, the purpose of which is to know the percentage of using this language on the one hand, and on the other hand, to know the percentage of its use between the two types. To conduct the research, (18) interviews and articles were taken from the visual media and the written press. After that, six components of the grammatical language were extracted, which are (linguistic accompaniment, coins (expressions), metaphor, proverbs, phrasal verbs, and lexical expressions) according to (Wadi), and the use of each one of them was indicated in a table.

Методы сетевого моделирования структуры семантической памяти: теоретический обзор

The article is aimed at considering the network modeling methods for human semantic memory structure. The work provides an analytical review of existing approaches to modeling the structure of human semantic memory, as a result of which the most methodologically optimal way of modeling semantic memory is estab-lished – based on the construction and analysis of semantic networks. The authors study various methods of network modeling of semantic memory structure: verbal fluency problem, snowball problem, semantic connec-tivity problem. In addition, examples of using these methods in psychological research are given, and their methodological advantages and disadvantages are highlighted. The results of the present work can be useful in the formation of new methods for network modeling of the structure of human semantic memory, as well as in the creation of intelligent systems that process graph data.

A neural decision signal during internal sampling from working memory in humans.

How humans transform sensory information into decisions that steer purposeful behaviour is a central question in psychology and neuroscience that is traditionally investigated during the sampling of external, environmental signals. The decision-making framework of gradual information sampling toward a decision has also been proposed to apply when sampling internal sensory evidence from working memory. However, neural evidence for this proposal remains scarce. Here we show (using scalp-EEG in male and female human volunteers) that sampling internal visual representations from working memory elicits a scalp-EEG potential associated with gradual evidence accumulation - the Central Parietal Positivity (CPP). Consistent with an evolving decision process, we show how this signal (i) scales with the time participants require to reach a decision about the cued memory content and (ii) is amplified when having to decide among multiple contents in working memory. These results bring the electrophysiology of decision making into the domain of working memory and suggest that variability in memory-guided behaviour may be driven (at least in part) by variations in the sampling of our inner mental contents.Significance Statement A foundational question in the study of mind and brain is how we transform sensory information into decisions that steer adaptive behaviour. This is traditionally investigated during the sampling of external, environmental signals. Here, we demonstrate that a canonical EEG marker of decision making from the human perception literature - the CPP - also tracks gradual decision making when selecting and accessing internally stored visual information from working memory. These findings bridge the literatures on decision making and working memory and suggest that trial-to-trial variability in memory-guided behaviour is driven, at least in part, by variations in the sampling of our inner mental contents.

Replication study on the role of dopamine-dependent prefrontal reactivations in human extinction memory retrieval

Even after successful extinction, conditioned fear can return. Strengthening the consolidation of the fear-inhibitory safety memory formed during extinction is one way to counteract return of fear. In a previous study, we found that post-extinction L-DOPA administration improved extinction memory retrieval 24 h later. Furthermore, spontaneous post-extinction reactivations of a neural activation pattern evoked in the ventromedial prefrontal cortex (vmPFC) during extinction predicted extinction memory retrieval, L-DOPA increased the number of these reactivations, and this mediated the effect of L-DOPA on extinction memory retrieval. Here, we conducted a preregistered replication study of this work in healthy male participants. We confirm that spontaneous post-extinction vmPFC reactivations predict extinction memory retrieval. This predictive effect, however, was only observed 90 min after extinction, and was not statistically significant at 45 min as in the discovery study. In contrast to our previous study, we find no evidence that L-DOPA administration significantly enhances retrieval and that this is mediated by enhancement of the number of vmPFC reactivations. However, additional non-preregistered analyses reveal a beneficial effect of L-DOPA on extinction retrieval when controlling for the trait-like stable baseline levels of salivary alpha-amylase enzymatic activity. Further, trait salivary alpha-amylase negatively predicts retrieval, and this effect is reduced by L-DOPA treatment. Importantly, the latter findings result from non-preregistered analyses and thus further investigation is needed.

Causal functional maps of brain rhythms in working memory

Human working memory is a key cognitive process that engages multiple functional anatomical nodes across the brain. Despite a plethora of correlative neuroimaging evidence regarding the working memory architecture, our understanding of critical hubs causally controlling overall performance is incomplete. Causal interpretation requires cognitive testing following safe, temporal, and controllable neuromodulation of specific functional anatomical nodes. Such experiments became available in healthy humans with the advance of transcranial alternating current stimulation (tACS). Here, we synthesize findings of 28 placebo-controlled studies (in total, 1,057 participants) that applied frequency-specific noninvasive stimulation of neural oscillations and examined working memory performance in neurotypical adults. We use a computational meta-modeling method to simulate each intervention in realistic virtual brains and test reported behavioral outcomes against the stimulation-induced electric fields in different brain nodes. Our results show that stimulating anterior frontal and medial temporal theta oscillations and occipitoparietal gamma rhythms leads to significant dose-dependent improvement in working memory task performance. Conversely, prefrontal gamma modulation is detrimental to performance. Moreover, we found distinct spatial expression of theta subbands, where working memory changes followed orbitofrontal high-theta modulation and medial temporal low-theta modulation. Finally, all these results are driven by changes in working memory accuracy rather than processing time measures. These findings provide a fresh view of the working memory mechanisms, complementary to neuroimaging research, and propose hypothesis-driven targets for the clinical treatment of working memory deficits.

Dissociable contributions of the medial parietal cortex to recognition memory.

Human neuroimaging studies of episodic memory retrieval routinely observe the engagement of specific cortical regions beyond the medial temporal lobe. Of these, medial parietal cortex (MPC) is of particular interest given its distinct functional characteristics during different types of retrieval tasks. Specifically, while recognition and autobiographical recall tasks are both used to probe episodic retrieval, these paradigms consistently drive distinct spatial patterns of response within MPC. However, other studies have emphasized alternate MPC functional dissociations in terms of brain network connectivity profiles or stimulus category selectivity. As the unique contributions of MPC to episodic memory remain unclear, adjudicating between these different accounts can provide better consensus regarding MPC function. Therefore, we used a precision neuroimaging dataset (7T fMRI) to examine how MPC regions are differentially engaged during recognition memory and how these task-related dissociations may also reflect distinct connectivity and stimulus category functional profiles. We observed interleaved, though spatially distinct, subregions of MPC where responses were sensitive to either recognition decisions or the semantic representation of stimuli. In addition, this dissociation was further accentuated by these functional subregions displaying distinct profiles of connectivity with the hippocampus during task and rest. Finally, we show that recent observations of dissociable person and place selectivity within MPC reflect category specific responses from within identified semantic regions that are sensitive to mnemonic demands. Together, by examining precision functional mapping within individuals, these data suggest previously distinct observations of functional dissociation within the MPC conform to a common principle of organization throughout hippocampal-neocortical memory systems.Significance Statement Medial parietal cortex (MPC) is ubiquitously implicated in studies of human episodic memory retrieval. Interestingly, distinct subregions of the MPC are engaged depending on the type of retrieval task being performed. Other types of functional dissociation have also been reported for MPC, focusing on brain network organization or stimulus selectivity. To reconcile these different functional views, we leveraged a precision neuroimaging dataset where participants performed thousands of recognition memory trials. We observed distinct MPC subregions supporting either recognition decisions or their semantic content, which recapitulated distinct patterns of hippocampal connectivity and visual category selectivity within MPC. These findings promote a common principle of functional organization that is shared amongst brain regions supporting episodic memory and advances our understanding of MPC.

DUEL: Duplicate Elimination on Active Memory for Self-Supervised Class-Imbalanced Learning

Recent machine learning algorithms have been developed using well-curated datasets, which often require substantial cost and resources. On the other hand, the direct use of raw data often leads to overfitting towards frequently occurring class information. To address class imbalances cost-efficiently, we propose an active data filtering process during self-supervised pre-training in our novel framework, Duplicate Elimination (DUEL). This framework integrates an active memory inspired by human working memory and introduces distinctiveness information, which measures the diversity of the data in the memory, to optimize both the feature extractor and the memory. The DUEL policy, which replaces the most duplicated data with new samples, aims to enhance the distinctiveness information in the memory and thereby mitigate class imbalances. We validate the effectiveness of the DUEL framework in class-imbalanced environments, demonstrating its robustness and providing reliable results in downstream tasks. We also analyze the role of the DUEL policy in the training process through various metrics and visualizations.

Vector Symbolic Finite State Machines in Attractor Neural Networks.

Hopfield attractor networks are robust distributed models of human memory, but they lack a general mechanism for effecting state-dependent attractor transitions in response to input. We propose construction rules such that an attractor network may implement an arbitrary finite state machine (FSM), where states and stimuli are represented by high-dimensional random vectors and all state transitions are enacted by the attractor network's dynamics. Numerical simulations show the capacity of the model, in terms of the maximum size of implementable FSM, to be linear in the size of the attractor network for dense bipolar state vectors and approximately quadratic for sparse binary state vectors. We show that the model is robust to imprecise and noisy weights, and so a prime candidate for implementation with high-density but unreliable devices. By endowing attractor networks with the ability to emulate arbitrary FSMs, we propose a plausible path by which FSMs could exist as a distributed computational primitive in biological neural networks.

Isotype switching in human memory B cells sets intrinsic antigen-affinity thresholds that dictate antigen-driven fates

Memory B cells (MBCs) play a critical role in protection against homologous and variant pathogen challenge by either differentiating to plasma cells (PCs) or to germinal center (GC) B cells. The human MBC compartment contains both switched IgG+ and unswitched IgM+ MBCs; however, whether these MBC subpopulations are equivalent in their response to B cell receptor cross-linking and their resulting fates is incompletely understood. Here, we show that IgG+ and IgM+ MBCs can be distinguished based on their response to κ-specific monoclonal antibodies of differing affinities. IgG+ MBCs responded only to high-affinity anti-κ and differentiated almost exclusively toward PC fates. In contrast, IgM+ MBCs were eliminated by apoptosis by high-affinity anti-κ but responded to low-affinity anti-κ by differentiating toward GC B cell fates. These results suggest that IgG+ and IgM+ MBCs may play distinct yet complementary roles in response to pathogen challenge ensuring the immediate production of high-affinity antibodies to homologous and closely related challenges and the generation of variant-specific MBCs through GC reactions.

The Use of Cognitive Paired Associative Stimulation (C-PAS) in Investigating and Remediating the Effects of Sleep Deprivation on Working Memory in Humans: The Importance of State-Dependency

Abstract Purpose of Review Sleep deprivation is a global health issue, and the resultant cognitive deficits can be debilitating. A series of studies reported success with individually neuronavigated transcranial magnetic stimulation (TMS), coupled with online task performance, in substantially reducing performance deficits in working memory in healthy adults caused by 2 days of total sleep depression. This paradigm of coupling TMS with online task performance has been referred to as Cognitive Paired Associative Stimulation (C-PAS). This review describes those studies and the research since using various TMS paradigms to remediate working memory deficits in sleep deprivation. Recent Findings Three such studies were found, but none replicated the earlier findings. However, in each case, there were differences in study design that might explain the negative findings and inform future methodological choices and to underline the need to combine TMS with brain imaging guidance. Summary Online task performance during TMS, as done in the C-PAS paradigm, appears to be essential to demonstrating lasting remediation of working memory deficits induced by sleep deprivation. This observation highlights the importance of state-dependency in determining the effects of TMS. Further work needs to be done to clarify the potential role of C-PAS in alleviating the effects of sleep deprivation and studying cognitive processes affected by sleep.

The saving enhanced memory effect can be observed when only a subset of items are saved.

Saving one list of words, such as on a computer or by writing them down, can improve a person's ability to learn and remember a second list of words that are not saved. This phenomenon, known as the saving enhanced memory effect, is typically observed by comparing the recall of nonsaved items when other items are saved versus when they are not saved. In past research, the effect has been shown to occur when participants save an entire list before learning a new list. In the current research, we examined whether the effect can be observed when participants save a subset of items within a single list. The results of two experiments confirmed that partial saving can lead to a saving enhanced memory effect, with the effect observed regardless of whether participants saved items by clicking a button on the computer or writing them out by hand. The effect was observed on an item-specific cued-recall test (Experiment 1) as well as a free recall test that did not control the order of output (Experiment 2). However, the effect size did vary as a function of how participants attempted to recall the items on the final test. Specifically, participants who initiated their output by recalling nonsaved items exhibited a significantly larger saving enhanced memory effect than those who initiated their output by reproducing saved items. Together, these findings expand our understanding of the saving enhanced memory effect and shine new light on the impacts of cognitive offloading on human memory.

Hippocampal subfields and their neocortical interactions during autobiographical memory

Abstract Advances in ultra-high field 7 Tesla functional magnetic resonance imaging (7 T fMRI) have provided unprecedented opportunities to gain insights into the neural underpinnings supporting human memory. The hippocampus, a heterogeneous brain structure comprising several subfields, plays a central role during vivid re-experiencing of autobiographical memories (AM). However, due to technical limitations, how hippocampal subfields differentially support AM, whether this contribution is specific to one portion along the hippocampal long-axis, and how subfields are functionally connected with other brain regions typically associated with AM retrieval remains elusive. Here, we leveraged technical advances of parallel imaging and employed a submillimeter Echo Planar Imaging sequence over the whole brain while participants re-experienced vivid, detail-rich AM. We found that all hippocampal subfields along the long-axis were engaged during AM retrieval. Nonetheless, only the pre/parasubiculum within the anterior body of the hippocampus contributed over and above to AM retrieval. Moreover, whole-brain functional connectivity analyses of the same data revealed that this part of the hippocampus was the only one that was strongly connected to other brain regions typically associated with AM, such as the ventromedial prefrontal cortex (vmPFC) and medial/lateral parietal regions. In the context of the broader literature, our results support recent proposals that the anterior body of the pre/parasubiculum may play an important role in scene-based cognition, such as its engagement during the re-experiencing of personal past events.

The Impact of Digital Technologies on Memory and Memory Studies

With the widespread integration of smartphones, computers, and the internet, information access and processing have undergone significant changes. This paper investigates both positive and negative implications, acknowledging the extension of cognitive capacities through easy access to vast databases and external memory aids while also addressing concerns about diminished memory consolidation and reliance on shallow encoding strategies. Examining the interdisciplinary field of memory studies, the study also highlights collaborative efforts among scholars in psychology, neuroscience, sociology, and information science to comprehend the impact of digital technologies on memory, and emphasizes the challenges and future directions in memory research, including issues like digital amnesia, information overload, and privacy concerns. Overall, the paper underscores the need for understanding the relationship between human memory and digital tools, enabling the development of strategies to enhance memory, counteract potential adverse effects, and promote a balanced utilization of digital resources in memory-related tasks.

The direction of theta and alpha travelling waves modulates human memory processing.

To support a range of behaviours, the brain must flexibly coordinate neural activity across widespread brain regions. One potential mechanism for this coordination is a travelling wave, in which a neural oscillation propagates across the brain while organizing the order and timing of activity across regions. Although travelling waves are present across the brain in various species, their potential functional relevance has remained unknown. Here, using rare direct human brain recordings, we demonstrate a distinct functional role for travelling waves of theta- and alpha-band (2-13 Hz) oscillations in the cortex. Travelling waves propagate in different directions during separate cognitive processes. In episodic memory, travelling waves tended to propagate in a posterior-to-anterior direction during successful memory encoding and in an anterior-to-posterior direction during recall. Because travelling waves of oscillations correspond to local neuronal spiking, these patterns indicate that rhythmic pulses of activity move across the brain in different directions for separate behaviours. More broadly, our results suggest a fundamental role for travelling waves and oscillations in dynamically coordinating neural connectivity, by flexibly organizing the timing and directionality of network interactions across the cortex to support cognition and behaviour.

Meaning of life and death during COVID-19 pandemic: A cultural and religious narratives

The sudden arrival of the coronavirus disease 2019 (COVID-19) pandemic in South Africa drastically changed the normal way of life in all sectors. It compelled everyone to look at the meaning of life and death differently and more painfully than before. This article investigates the cultural theories and religious narratives on the meaning of life and death, associated with the pervasiveness of the COVID-19 pandemic. The coronavirus affected individuals, families and communities, some directly or indirectly, no one is or was immune to the virus. The article argues that due to COVID-19 restrictions and lockdowns, culture, religious practices and protocols have been upended. The COVID-19 pandemic challenged inkcubeko nenkolo yabantu [culture, people’s religious belief systems and practices]. This article consists of in-depth qualitative interviews with four religious leaders from the Christian and Muslim faiths. Because of the interviews with persons, oral historians conduct open-ended interviews, as a form of social inquiry. Oral history narratives thus connect the individual and the social, drawing on cultural and religious expressions to tell one’s story.Contribution: The scholarly contribution of this article adds value and significance to oral history research, as a way of collecting and interpreting human memories and experiences on the meaning of life and death during the COVID-19 crisis. It discusses the dreadfulness of the COVID-19 scourge concerning religious and cultural effects, social sciences and people’s narrative reflections.

Acute Treatment with the Nootropic CILTEP® Does Not Improve Cognitive Performance in Healthy Middle-Aged Participants

AbstractThis study investigated the acute effects of the dietary nootropic stack CILTEP®. It contains a combination of ingredients that have been individually reported to improve cognitive performance. Especially, the ingredients luteolin, which is considered a phosphodiesterase type 4 (PDE4) inhibitor, and forskolin, an adenylate cyclase stimulator, were of interest since they can increase the second messenger cAMP and thus also intracellular signaling. Numerous studies have shown that inhibition of PDE4 can improve memory in animals and humans. We examined whether acute dosing of 3 capsules of CILTEP® would improve cognitive function in healthy participants aged 30 to 40 (n = 33). We used a randomized, double-blind, placebo-controlled, two-way cross-over design. Our test battery was aimed at measuring memory performance, attention, and sensorimotor speed. The primary outcome measures were the performance on the verbal learning task and the spatial pattern separation task. Secondary outcomes included other cognitive tests, event-related potentials (ERPs), and assessment of the activity of the enzyme beta-glucuronidase and its effect on the bioavailability of luteolin, heart rate, and blood pressure. No relevant effects of acute CILTEP® treatment were found on any measure of the test battery or ERPs. Blood plasma concentrations of luteolin increased, yet about 2000 times too low to likely exert any PDE4 inhibition. CILTEP® treatment did neither affect heart rate nor blood pressure. In summary, there is no evidence that a single standardized dose of 3 capsules of CILTEP® can improve cognitive function in healthy middle-aged participants.

Sex differences in the context dependency of episodic memory.

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.

Narrative strategy of life story in the literature of Margaret Atwood

The subject of the research in this article is the narrative strategy of life description in the work of Margaret Atwood. Margaret Atwood (b. 1939) is a well–known modern Canadian writer, poet, and literary critic. The work of M. Atwood is considered in three main directions: the search for Canadian identity in the works of M. Atwood; the women's question and theories of feminism in the works of M. Atwood and speculative (conceptual) fiction in the works of M. Atwood. It is these three areas that the largest number of scientific papers about the Canadian writer are devoted to. Based on the life and creative path of M. Atwood, these three highways are justified. But behind them, the basis of the writer's work is lost – the narrative structure, to the study of which M. Atwood devoted many of her literary works. Based on the best practices of foreign and domestic narrative researchers, as well as on the research of M. Atwood herself, in this article we describe how a multi-level narrative of biography unfolds in the writer's fiction, implying a division into narrative layers. Each narrative layer is responsible for a certain time: the past, the present and the timelessness. The relevance and novelty of this article lies in an attempt to describe the narratives of M. Atwood, in isolation from the three main paths, and highlight the features of the narrative of the biography, which is key to the author's works. Thanks to the strategy of biography, the Canadian writer explores the nature of human memory, thinking, and fantasy. By placing the main character, the narrator, at the center of the narrative, M. Atwood allows her characters to independently analyze their own actions, their past, which brings her characters closer to real people. The characters of the writer, like real people, have general ideas about how a story should be built, a story and use literary techniques in talking about themselves. But, gradually opening up, the characters are the narrators of M. Atwood turns to a frank conversation, discarding literary decorations. The approach to the work of M. Atwood from the point of view of narrative, narratology helps to open new facets in the work of the famous author, to emphasize and actualize many artistic features of M. Atwood's books. Atwood, who remain in the shadows with a cultural and ideological approach.

IL23R G149R Promotes IL-23 Unresponsiveness in Human Memory Th17 Cells

IL23R G149R Promotes IL-23 Unresponsiveness in Human Memory Th17 Cells