Memory Patterns Research Articles

Колдуны и ведуньи: магические практики албанцев Украины в парадигме антропологии

The study tries to determine the status and ways of existence of magical practices among the descendants of the Balkan colonists in the contact zones of Ukraine. The most important issue of humanitarian research in recent decades is to identify the conditions and mechanisms for the preservation of archaic beliefs and the entry of innovations into the sacred sphere. In the conditions of globalization of information exchange, rules, value judgments and seemingly unshakable beliefs of people are rapidly changing. The Albanians of Budzhak and the Sea of Azov keep beliefs and practices, largely unchanged from the time they lived in the area of their origin, the analysis of which will help to understand the mechanism for preserving traditional ideas and transforming the cultural code under the influence of external factors — primarily the media, the Internet, etc. The study is based on many years of field observations of the author, conducted from 1998 to 2021 both on the territory of Ukraine and the Balkans. The author draws on theoretical models developed in cultural and social anthropology by researchers who studied the phenomenon of cultural memory on French, Moldovan and Macedonian materials. The historical approach allows us to identify the fundamental patterns of the genesis of cultural memory and the evolution of magical practices.

The role of intergenerational family stories in mental health and wellbeing.

Patterns of memory sharing begin early in one’s life, informing relationships, one’s history, and one’s sense of cultural belonging. Memory sharing among families has been the focus of research investigating the relationship between mental health and intergenerational memory. A burgeoning body of research is showing that intergenerational knowledge of one’s family history is associated with positive mental health and wellbeing. However, research on the specific mechanisms and potential applications of such findings are just beginning to emerge. In particular, studies examining intergenerational storytelling point to the importance of culture and gender as critical factors underlying how stories are told and the extent to which these stories are associated with wellbeing. Such findings hold important promise for the pentation and treatment of mental health issues. As research in this area continues to evolve, the identification and characterization of factors and mechanisms underlying intergenerational family stories and wellbeing may help to guide the integration of family stories into mental health interventions.

Gamma-Band Modulation in Parietal Area as the Electroencephalographic Signature for Performance in Auditory-Verbal Working Memory: An Exploratory Pilot Study in Hearing and Unilateral Cochlear Implant Children.

This pilot study investigates the neurophysiological patterns of visual and auditory verbal working memory (VWM) in unilateral cochlear implant users (UCIs). We compared the task-related electroencephalogram (EEG) power spectral density of 7- to 13-year-old UCIs (n = 7) with a hearing control group (HC, n = 10) during the execution of a three-level n-back task with auditory and visual verbal (letters) stimuli. Performances improved as memory load decreased regardless of sensory modality (SM) and group factors. Theta EEG activation over the frontal area was proportionally influenced by task level; the left hemisphere (LH) showed greater activation in the gamma band, suggesting lateralization of VWM function regardless of SM. However, HCs showed stronger activation patterns in the LH than UCIs regardless of SM and in the parietal area (PA) during the most challenging audio condition. Linear regressions for gamma activation in the PA suggest the presence of a pattern-supporting auditory VWM only in HCs. Our findings seem to recognize gamma activation in the PA as the signature of effective auditory VWM. These results, although preliminary, highlight this EEG pattern as a possible cause of the variability found in VWM outcomes in deaf children, opening up new possibilities for interdisciplinary research and rehabilitation intervention.

Altering the past to shape the future: Manipulating information accessibility to influence case-based reasoning

One strategy for decision-making involves the process known as case-based reasoning, where individuals retrieve past decisions in similar cases, compare the new and old situation, and adapt previous decisions to the new context. However, remembering past cases is a selective process. Research on retrieval-induced forgetting found that retrieving a subset of information about a certain topic causes forgetting of related information. In two experiments we use retrieval-induced forgetting to activate and deactivate similar features between a new case and past cases. We measured whether this intervention impacted decision-making about a controversial policy and whether the positive and negative outcomes of past cases influenced both information accessibility and decision-making. Study 1 demonstrated socially-shared retrieval-induced forgetting: hearing others talk about non-critical features from the past cases reduced memory accessibility of critical but unmentioned features of the positive past case (i.e., success), but not for negative past case (i.e., failure), compared with a control condition. Study 2 demonstrated that individuals' decisions were consistent with the manipulated memory pattern. Individuals were less supportive of the controversial policy in a new case when they heard non-critical information in the positive past case, whereas individuals were no less supportive when hearing non-critical information in the negative past case, compared with the control condition. We speculate that failure to trigger retrieval-induced forgetting in negative cases might be due to a negativity bias in information processing. We discuss the implication of these results for real-world phenomena involving people using the past to reason about the future.

Lipophorin receptors regulate mushroom body development and complex behaviors in Drosophila

BackgroundDrosophila melanogaster lipophorin receptors (LpRs), LpR1 and LpR2, are members of the LDLR family known to mediate lipid uptake in a range of organisms from Drosophila to humans. The vertebrate orthologs of LpRs, ApoER2 and VLDL-R, function as receptors of a glycoprotein involved in development of the central nervous system, Reelin, which is not present in flies. ApoER2 and VLDL-R are associated with the development and function of the hippocampus and cerebral cortex, important association areas in the mammalian brain, as well as with neurodevelopmental and neurodegenerative disorders linked to those regions. It is currently unknown whether LpRs play similar roles in the Drosophila brain.ResultsWe report that LpR-deficient flies exhibit impaired olfactory memory and sleep patterns, which seem to reflect anatomical defects found in a critical brain association area, the mushroom bodies (MB). Moreover, cultured MB neurons respond to mammalian Reelin by increasing the complexity of their neurite arborization. This effect depends on LpRs and Dab, the Drosophila ortholog of the Reelin signaling adaptor protein Dab1. In vitro, two of the long isoforms of LpRs allow the internalization of Reelin, suggesting that Drosophila LpRs interact with human Reelin to induce downstream cellular events.ConclusionsThese findings demonstrate that LpRs contribute to MB development and function, supporting the existence of a LpR-dependent signaling in Drosophila, and advance our understanding of the molecular factors functioning in neural systems to generate complex behaviors in this model. Our results further emphasize the importance of Drosophila as a model to investigate the alterations in specific genes contributing to neural disorders.

Investigating long range dependence in temperatures in Siberia

In this paper we examine monthly mean temperatures in 40 selected stations in Siberia for the time period January 1937–December 2020 using long range dependence techniques. In particular, we use a fractionally integrated model that incorporates a linear time trend along with a seasonal structure. Our results show first that long memory is present in all stations with significantly positive values for the differencing parameter, though, at the same time the seasonal component seems to be important in all cases. Performing seasonal unit root tests, the results support nonstationary seasonality and working with the seasonal differenced data, the results differ depending on the structure of the error term: if the errors are uncorrelated, long memory is present; however, allowing autocorrelation, this feature disappears in favor of a short memory pattern.

Dual memory scale network for multi-step time series forecasting in thermal environment of aquaculture facility: A case study of recirculating aquaculture water temperature

Multi-step time series forecasting is essential in engineering. However, effective time series prediction of the agricultural environment is still a challenge due to the disturbance of external factors and the complexity of temporal patterns. The objective of this work is to provide an intelligent prediction system with field priori-knowledge for aquaculture facility thermal environment. Specifically, we present a novel network framework that considers the spatial correlation of exogenous environmental factors, the short-term and long-term temporal dependence of the sequence, and the spatio-temporal fusion correlation at different times. Among them, the dual-scale memory components focus on long-term seasonal and trend memory patterns as well as short-term fluctuation memory patterns, respectively. Besides, the attention mechanism coordinates the information flow between the long and short memory components. We applied the model to recirculating water temperature forecasting in the aquaponics greenhouse. The empirical results of global and local metrics indicate that our proposed model outperforms benchmark models. The RMSE of the proposed dual memory scale network (DMSNet) is 0.1631, 0.3206, and 0.3761, respectively, in the next 6 h, 12 h, and 24 h water temperature prediction. Ablation study proved that the components of our proposed network could be targeted to extract different information patterns from aquaponics environmental sequence data. Experimental results show that the thermal environment prediction based on DMSNet has higher precision in short-term and long-term forecasting multi-step prediction.

Age-dependent associations of risk factors for cardiovascular diseases with the state of cognitive functions

The aim of the study was to provide a population assessment of cognitive impairment patterns in a representative sample of 25–44 year old men and women living in Western Siberia with metabolic syndrome (MS). The aim of the study is to study the features of the interrelationships of conventional and nonconventional risk factors for cardiovascular diseases (RF CVD), molecular genetic markers with the state of cognitive functions (CF), objective–subjective index of CF in an open population in persons aged 14–17, 25–44 years (Novosibirsk).Material and methods: A singlestage population survey of a random representative sample of 25–44 year olds of both sexes (1503 people) permanently residing in Western Siberia (Novosibirsk) was performed. The study of the state of cognitive functions was conducted in 1009 people: 463 men (45.9 %) and 546 women (54.1 %). The object of the study was random representative samples of the population of Novosibirsk, formed during the screenings of the NIITPM branch of the ICIG SB RAS. The paper uses materials from a one-stage population survey of adolescents (screenings 2009–2010 and 2019) and persons aged 25–44 years (screening 2013–2016). According to the methods standardized during the screening, the following were performed: a 10-word memorization test, a proof-reading test, and a concept exclusion test. Anthropometric measurements were carried out. Determination of the levels of lipid fractions was carried out according to standardized methods. Genotyping of rs2464196 HNF1A and rs11212617 ATM was carried out using real-time PCR.Results. In the examined samples of Novosibirsk residents aged 14–17 and 25–44 years, statistically significant negative associations of RF CVD with neurodynamic CF were observed. Proatherogenic conventional RF CVD had a negative impact on attention and thinking patterns (among the most significant were the content of total cholesterol (odds ratio (OR) 0.996; 95 % confidence interval (95 % CI) 0.993–1,000; p = 0.043), low density lipoprotein cholesterol (OR 0.994; 95 % CI 0.990–0.998; p = 0.002)). The factors reducing the risk of deterioration of CF in 25–44 year olds were the presence of higher education (OR 2,350; 95 % CI 1,442–3,828; p = 0.001), female (OR 2,068; 95 % CI 1,552–2,754; p < 0.0001). In the cohort analysis, it was revealed that the studied conventional RF CVD undergo statistically significant changes in the direction of their increase during adulthood over the past 5 years (p < 0.05). It was shown that metabolic syndrome (MS) occurred in every fourth person tested for CF (26.06 %), while the values of cognitive tests were higher in people without MS compared to those who were diagnosed with MS (p < 0,05). Smoking had a negative effect on the memory pattern, causing a deterioration in the memorization of words (OR 1,071; 95 % CI 1,012–1,133); (p = 0.017). The deterioration of memory, attention and thinking patterns in the presence of workplace stress and low professional status, – important unconventional RF CVD, – has been established (p < 0.05)).Conclusion. In the open population of adolescents and young people (25–44 years old), a statistically significant deterioration of cognitive patterns was found in the presence of the studied conventional and non-conventional RF CVD.

Using tactile imagery to teach geometry to students with visual impairments in the United Arab Emirates

Learning geometry is difficult for students with visual impairments (VIs). However, tactile imagery, the process of constructing mental images of physical objects with certain shapes, may help them make sense of geometrical shapes. Thus, discussions have centred on interventions to promote the participation of students with VIs in the learning of shapes. This study explored tactile imagery connecting physical touch to memory as an approach to teaching shapes to students with VIs. Eleven students, five with VIs and six sighted students took part in this experimental design study. A tactile imagery test and intervention lessons were developed for this study. Four tactile imagery domains (tactile discrimination, tactile memory 2D, tactile memory 3D and pattern recall), each made up of 10 tests, guided the design of the tests and training lessons. The students’ scores from the pre-test and post-test were subjected to mean computations, Mann-Whitney U tests and the Wilcoxon signed-rank test. The post-test results revealed that students with VIs performed better than their sighted peers. The study concludes with a discussion of the need for teacher educators to consider using tactile imagery as a way of teaching geometry to students with VIs.

Evaluation of gem5 for performance modeling of ARM Cortex-R based embedded SoCs

ARM CPUs are prevalent in embedded systems ranging from low-power IoT to reasonably high-powered mobile phones and devices. Embedded SoCs integrate a number of accelerators with CPUs to achieve the tight performance and power budget. To overcome the challenges of architecting these complex SoCs, designers employ performance simulators as a design space exploration tool. Developing such a simulator infrastructure in itself is challenging and depends on accurately modeling the ARM CPUs and the interaction of various accelerators with the CPU. The widely used, open-source gem5 simulator provides the necessary components to develop such an infrastructure in a time and cost-effective manner. In this paper, we present the limit study and evaluation of using gem5 for building a performance modeling and analysis framework targeted to ARM R series CPU-based embedded SoC. First, we illustrate the approach to develop the framework by tuning the extensive configuration space of gem5 and making modifications for new features. We consider different CPUs, branch predictors, memory modules, and SystemC coupling in gem5. Second, we perform a detailed correlation of the simulator with a real ARM CPU and explain the shortcomings, challenges, and ways to improve the accuracy. We obtain average absolute errors of 13% for the Embench suite Bennett et al. (2019). We also point out large miscorrelations for specific pattern in ALU (50%), Branch (135%) and Memory (35%). Finally, through a case study to design a flexible NVMe SSD controller architecture, we demonstrate the framework’s design space exploration capabilities.

Episodic memory updating among older adults: moderating role of prior knowledge

ABSTRACT Memory updating is an adaptive function that requires people’s registry of changes of episodes. However, the research on the role of prior knowledge on memory updating among older adults is scant. We instructed young and older adults to learn two sets of pairs with overlapping scene (A) on Day 1 (A-B) and Day 2 (A-C) and tested the competing memories on Day 3. We further manipulated the schema-congruency between item (B/C) and scene (A). Young adults performed comparatively well in the A-B and A-C memory tests, and showed no difference under different congruency conditions. However, memory updating among older adults was moderated by prior knowledge, with better memory performance in A-C test relative to A-B test when the to-be-updated item C was schema-congruent, however, with poorer memory performance in the A-C test when the to-be-updated item is schema-incongruent. This study advances the understanding that prior knowledge significantly contributes to memory updating among older adults. They would experience retroactive interference when the to-be-updated memories were consistent with their prior knowledge, yet proactive interference when the to-be-updated memories were inconsistent with their prior knowledge. Meanwhile, prior knowledge among young adults does not affect memory updating, given that their memory patterns are consistent across congruency conditions.

A quantitative analysis of a generalized Hopfield model that stores and retrieves mismatched memory patterns

We study a class of Hopfield models where the memories are represented by a mixture of Gaussian and binary variables and the neurons are Ising spins. We study the properties of this family of models as the relative weight of the two kinds of variables in the patterns varies. We quantitatively determine how the retrieval phase squeezes toward zero as the memory patterns contain a larger fraction of mismatched variables. As the memory is purely Gaussian retrieval is lost for any positive storage capacity. It is shown that this comes about because of the spherical symmetry of the free energy in the Gaussian case. Introducing two different memory pattern overlaps between spin configurations and each contribution to the pattern from the two kinds of variables one can observe that the Gaussian parts of the patterns act as a noise, making retrieval more difficult. The basins of attraction of the states, the accuracy of the retrieval and the storage capacity are studied by means of Monte Carlo numerical simulations. We uncover that even in the limit where the network capacity shrinks to zero, the (few) retrieval states maintain a large basin of attraction and large overlaps with the mismatched patterns. So the network can be used for retrieval, but with a very small capacity.

More elaborate processing of own-race faces and less elaborate processing of other-race faces contribute to the other-race effect in face memory.

Research suggests that own-race faces are naturally memorized in a more elaborate (e.g., many features of a face or the whole face) way, whereas other-race faces are memorized in a less elaborate (e.g., only selected features of the face) manner. Here, we tested if instructions for judgements about the whole face and a single facial feature modulated the other-race effect in face memory. White participants performed whole-face and single-feature tasks while memorizing White and Black faces for later recognition. Encoding instructions had a stronger impact on own-race than other-race faces. Whole-face instructions increased the other-race effect, whereas single-feature instructions decreased it. Own-race faces in the whole-face task demonstrated event-related potential (ERP) patterns of memory encoding comparable to previously observed natural memory encoding, suggesting naturally more elaborate encoding of own-race faces. ERPs of memory encoding for other-race faces were similar between task conditions and comparable to previously observed natural encoding patterns, suggesting naturally less elaborate encoding. No impact of the encoding tasks was found on ERPs related to memory retrieval, which may be an artefact of a perceptual task that does not enhance semantic details in memory. The current results indicate that some contributions to the other-race effect are more elaborate (more detailed) memory encoding for own-race faces and less elaborate (less detailed) memory encoding for other-race faces. This study also provides evidence for more malleability of own-race than other-race faces through task instructions, consistent with assumptions of perceptual learning theories of the other-race effect.

خلیل الرحمٰن داؤدی کی مخطوطات پر یادداشت نویسی

Khalīl al-Raḥmān Dā’ūdī (1923-2002) was a versatile personality. Most of his work is about manuscripts, research and editing. He edited more than twenty 20 classical Urdu books, sixteen of them are published and four are still unpublished. He was famous for his good knowledge of manuscripts. He wrote notes on more than three thousand and five hundred manuscripts of different languages like Persian, Arabic, Urdu and Punjabi. Scholars of literature praised his research on manuscripts. This article is about the principles of catalogue in practical form and also a review of some samples notes written by Dā’ūdī. It is also a comparison of Dā’dī’s cataloging with other catalogues. No doubt it is an important addition to the chapter of codicology. This research explores the patterns of memories for the past scholarship they worked on different manuscripts for literature and languages.

Abstract 1970: Single cell proteomic quantification of T cell states using mass cytometry for applications in monitoring immune responses in cancer immunotherapy clinical trials

Abstract Although immunotherapies have been established as a successful treatment option for several types of cancers, additional treatment strategies are necessary to broaden the cohorts of patients who may receive clinical benefit. Common immunological profiling for immunotherapy response depends on assessment of the composition of immune cell types in tissue samples and the periphery. Still, the function and state of each of these cells further contributes to the ultimate clinical benefit of immunotherapeutic response. Additionally, our ability to comprehensively study treatment strategies depends on elucidating the temporal effects different immunotherapy regimens have on the immune system of patients. Single-cell proteomics profiling with CyTOF mass cytometry enables robust protein-level profiling of cell types and is also high-dimensional enough to characterize functional states of immune cells. To construct an immunological framework that may feasibly serve to empower functional assessment of immune cell states for clinical trial monitoring strategies using CyTOF, we are employing single cell trajectory inference methods and non-negative matrix factorization (NMF). We demonstrate this approach using peripheral blood derived CyTOF mass cytometry data to model T cell states at the proteomic level. First, we extract T helper (Th) and T cytotoxic (Tc) cell integrated metrics from CyTOF mass cytometry data obtained from diverse cell marker panel designs, immunological states, and diseases to benchmark that these computational pipelines can accurately reflect Th and Tc activation and exhaustion. Next, we develop a new pipeline that enables the use of continuous functional cell-state metrics from continuous pseudotime and NMF pattern weights as immunological profiling markers from CyTOF that can be applied to cancer immunotherapy clinical trials. For instance, we find CyTOF Tc pseudotime and memory pattern weights are higher in PDAC patients with stable disease treated with ipilimumab and a pancreatic cancer-specific vaccine. Thus, our pipeline has the ability to integrate metrics from mass cytometry data to empower translational analyses for determining patient responses in cancer immunotherapy, such as adaptive immune responses to checkpoint inhibitors and cancer vaccines. Moreover, applying this pipeline to peripheral blood samples obtained before and after treatment also enables us to map further temporal cell state transitions in Tc and Th cells resulting from that treatment. Future work will include leveraging CyTOF T cell integrated metrics in larger scale survival analyses to test the predictive potential in a clinical proof of concept. Citation Format: Dimitrios N. Sidiropoulos, Zaw Phyo, Nicole Gross, Soren Charmsaz, Stephanie Xavier, James Leatherman, Mark Yarchoan, Elizabeth M. Jaffee, Elana J. Fertig, Won Jin Ho. Single cell proteomic quantification of T cell states using mass cytometry for applications in monitoring immune responses in cancer immunotherapy clinical trials [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1970.

Abstract 3802: Micromilieu-dependent transcriptional memory of tumor vessel endothelial cells in colorectal cancer

Abstract Purpose of the study: Tumor microenvironment (TME)-induced plasticity of fibroblasts and immune cells are known to contribute to cancer pathogenesis. In contrast, only little is known about the existence, stability, functions and prognostic potential of different plastic phenotypes of tumor vessel endothelial cells (TECs) in cancer. Recently, transcriptional memory effects have been observed in different cell lines after cytokine stimulation in vitro. From this we developed the hypothesis that isolated TEC may exhibit TME-dependent transcriptional memories, which may provide novel insights into the intratumoral effects on TEC plasticity in cancer. To investigate this, we isolated ultrapure TECs from colorectal cancer (CRC) with prognostically favorable (Th-1-like) or worse (non-Th1-like) immune-micro-environments and analyzed the prescence of TME-associated transcriptional memory patterns. Methods: TECs and as controls normal colon endothelial cells (NECs), PBMCs and tumor cells (isolated by laser-microdissection) from the same CRC patients (n=75) were isolated by FACS-sorting. Ultra high purity (98%) of TECs and NECs was validated by qPCR and immunocytochemistry. Quality validated complete sample sets from 12 patients (Th-1-like, n=6, non-Th1-like, n=6) were compared using exome sequencing, Clariome S chips and EPICmethylation. Integrative bioinformatics was used to identify differential gene sets and to predict their association with prognosis. Results: Differential transcriptional memory patterns were detected in TECs derived from CRC with different prognostic TMEs. Of note, the aggressiveness of the originating tumors was reflected by the functions of the vascular transcriptional memory genes. The transcriptional memory was imprinted by epigenetic DNA methylation and not due to acquired somatic variants in the genome. These results could be successfully confirmed by alternative methods. Most importantly, integrative bioinformatics analyses retrieved seven vascular memory genes (VMG), which were expressed in the TECs in a TME-dependent manner and predicted the outcome of patients in an independent cohort of CRC patients. Conclusion: Our findings demonstrate for the first time a TME-dependent transcriptional memory of TECs, providing a clinically relevant indicator of intra-tumoral TME-dependent vascular plasticity with perspectives for patient stratification in vessel-directed tumor therapies. Citation Format: Michael Stürzl, Maximilian Fuchs, Meik Kunz, Nicholas Dickel, Bernt Popp, Steffen Uebe, Arif B. Ekici, Carol I. Geppert, Susanne Merkel, Vera S. Schellerer, Elisabeth Naschberger. Micromilieu-dependent transcriptional memory of tumor vessel endothelial cells in colorectal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3802.

What does it mean to represent? Mental representations as falsifiable memory patterns

Representation is a key notion in neuroscience and artificial intelligence (AI). However, a longstanding philosophical debate highlights that specifying what counts as representation is trickier than it seems. With this brief opinion paper we would like to bring the philosophical problem of representation into attention and provide an implementable solution. We note that causal and teleological approaches often assumed by neuroscientists and engineers fail to provide a satisfactory account of representation. We sketch an alternative according to which representations correspond to inferred latent structures in the world, identified on the basis of conditional patterns of activation. These structures are assumed to have certain properties objectively, which allows for planning, prediction, and detection of unexpected events. We illustrate our proposal with the simulation of a simple neural network model. We believe this stronger notion of representation could inform future research in neuroscience and AI.

The Distinctive Pattern of Declarative Memories in Autism Spectrum Disorder: Further Evidence of Episodic Memory Constraints.

This study examines declarative memory retrieval in ASD depending on the availability and access to stored conceptual knowledge. Fifteen autistic participants and a matched control group of 18 typically-developed (TD) volunteers completed a Remember-Know paradigm manipulated by encoding-type (categorical, perceptual) and item-typicality (high-typical, low-typical). The autistic group showed worse and slower recognition and less recollection but equivalent familiarity-based memories compared to TDs. Notably, low-typical items did not improve their memories as they did for TDs, likely due to difficulties in matching low-fit information to the stored schema. Results suggest that memory decline in ASD may derive from the episodic system and its dynamics with the semantic system. These findings may inform interventional strategies for enhancing learning abilities in ASD.

Role of Sleep in Formation of Relational Associative Memory.

Relational memory, the ability to make and remember associations between objects, is an essential component of mammalian reasoning. In relational memory tasks, it has been shown that periods of offline processing, such as sleep, are critical to making indirect associations. To understand biophysical mechanisms behind the role of sleep in improving relational memory, we developed a model of the thalamocortical network to test how slow-wave sleep affects performance on an unordered relational memory task. First, the model was trained in the awake state on a paired associate inference task, in which the model learned to recall direct associations. After a period of subsequent slow-wave sleep, the model developed the ability to recall indirect associations. We found that replay, during sleep, of memory patterns learned in awake increased synaptic connectivity between neurons representing the item that was overlapping between tasks and neurons representing the unlinked items of the different tasks; this forms an attractor that enables indirect memory recall. Our study predicts that overlapping items between indirectly associated tasks are essential for relational memory, and sleep can reactivate pathways to and from overlapping items to the unlinked objects to strengthen these pathways and form new relational memories.SIGNIFICANCE STATEMENT Experimental studies have shown that some types of associative memory, such as transitive inference and relational memory, can improve after sleep. Still, it remains unknown what specific mechanisms are responsible for these sleep-related changes. In this new work, we addressed this problem by building a thalamocortical network model that can learn relational memory tasks and that can be simulated in awake or sleep states. We found that memory traces learned in awake were replayed during slow waves of NREM sleep and revealed that replay increased connections to and from overlapping memory items to form new relational memories. Our work discovered specific mechanisms behind the role of sleep in associative memory and made testable predictions about how sleep augments associative learning.

Sex-specific associations in verbal memory brain circuitry in early psychosis

Hippocampal circuitry and related cortical connections are altered in first episode psychosis (FEP) and are associated with verbal memory deficits, as well as positive and negative symptoms. There are robust sex differences in the clinical presentation of psychosis, including poorer verbal memory in male patients. Consideration of sex differences in hippocampal-cortical circuitry and their associations with different behavioral dimensions may be useful for understanding the underlying pathophysiology of verbal memory deficits and related symptomatology in psychosis. Here, we use a data-driven approach to simultaneously capture the complex links between sex, verbal memory, symptoms, and cortical-hippocampal brain metrics in FEP. Structural magnetic resonance imaging and behavioral data were acquired from 100 FEP patients (75 males, 25 females) and 87 controls (55 males, 32 females). Multivariate brain-behavior associations were examined in FEP using partial least squares to map sociodemographic, verbal memory, and clinical data onto brain morphometry. The analysis identified two sex-dependent patterns of verbal memory, symptoms, and brain structure. In male patients, verbal memory deficits and core psychotic symptoms were associated with both increased and decreased frontal and temporal cortical thickness and reductions in CA2/3 hippocampal subfield and fornix volumes. In female patients, fewer negative/depressive symptoms were associated with a more attenuated cortical thickness pattern and more diffuse reductions in hippocampal white matter regions. Taken together, the results contribute towards better understanding the underlying pathophysiology of psychosis by highlighting the unique contribution of specific hippocampal subfields and surrounding white matter and their connections with broader cortical networks in a sex-dependent manner.