Collective memory: between individual systems of consciousness and social systems.

Following a long period of neglect, research on different facets of collective memory is now developing apace in the human and social sciences, as well as at their interface with psychology and neuroscience. This resolutely multidisciplinary renewal of interest in memory sciences has given rise to a plethora of concepts with diverse meanings (e.g., social frameworks of memory, collective, shared, collaborative, social memory). The purpose of the present study was to provide a conceptual overview from a historical perspective, and above all to clarify concepts that are often used interchangeably, even though they refer to very different realities. Based on recent research in psychology and neuroscience, we use the concept of collective memory to refer to the operations of individual systems of consciousness. Collective memory is not the memory of a collective, but that of its individual members, either as members of social groups (shared memory) or as participants in social interactions (collaborative memory). Drawing on the contributions of contemporary sociology, we show that social memory is not collective memory, as it refers not to individual systems of consciousness, but to social systems. More specifically, it is the outcome of communication operations which, through redundancy and repetition, perform a continuous and selective re-imprinting of meaning that can be used for communication. Writing, printing and the new communication technologies constitute the three historical stages in the formation and development of an autonomous social memory, independent of living memories and social interactions. In the modern era, mass media fulfill an essential function of social memory, by sorting between forgetting and remembering on a planetary scale. When thinking about the articulation between collective memory and social memory, the concept of structural coupling allows us to identify two mechanisms by which individual systems of consciousness and social systems can interact and be mutually sensitized: schemas and scripts, and social roles. Transdisciplinary approach spearheads major methodological and conceptual advances and is particularly promising for clinical practice, as it should result in a better understanding of memory pathologies, including PTSD, but also cognitive disorders in cancer (chemobrain) or in neurodegenerative diseases.

Efficient simulation of neural development using shared memory parallelization.

The Neural Development Simulator, NeuroDevSim, is a Python module that simulates the most important aspects of brain development: morphological growth, migration, and pruning. It uses an agent-based modeling approach inherited from the NeuroMaC software. Each cycle has agents called fronts execute model-specific code. In the case of a growing dendritic or axonal front, this will be a choice between extension, branching, or growth termination. Somatic fronts can migrate to new positions and any front can be retracted to prune parts of neurons. Collision detection prevents new or migrating fronts from overlapping with existing ones. NeuroDevSim is a multi-core program that uses an innovative shared memory approach to achieve parallel processing without messaging. We demonstrate linear strong parallel scaling up to 96 cores for large models and have run these successfully on 128 cores. Most of the shared memory parallelism is achieved without memory locking. Instead, cores have only write privileges to private sections of arrays, while being able to read the entire shared array. Memory conflicts are avoided by a coding rule that allows only active fronts to use methods that need writing access. The exception is collision detection, which is needed to avoid the growth of physically overlapping structures. For collision detection, a memory-locking mechanism was necessary to control access to grid points that register the location of nearby fronts. A custom approach using a serialized lock broker was able to manage both read and write locking. NeuroDevSim allows easy modeling of most aspects of neural development for models simulating a few complex or thousands of simple neurons or a mixture of both. Code available at: https://github.com/CNS-OIST/NeuroDevSim.

Joint contributions of collaborative facilitation and social contagion to the development of shared memories in social groups.

Social interactions can shape our memories. Here, we examined two well-established effects of collaborative remembering on individual memory: collaborative facilitation for initially studied and social contagion with initially unstudied information. Participants were tested in groups of three. After an individual study phase, they completed a first interpolated test either alone or collaboratively with the other group members. Our goal was to explore how prior collaboration affected memory performance on a final critical test, which was taken individually by all participants. Experiments 1a and 1b used additive information as study materials, whereas Experiment 2 introduced contradictory information. All experiments provided evidence of collaborative facilitation and social contagion on the final critical test, which affected individual memory simultaneously. In addition, we also examined memory at the group level on this final critical test, by analyzing the overlap in identical remembered contents across group members. Here, the experiments showed that both collaborative facilitation for studied information and social contagion with unstudied information contributed to the development of shared memories across group members. The presence of contradictory information reduced rates of mnemonic overlap, confirming that changes in individual remembering have repercussions for the development of shared memories at the group level. We discuss what cognitive mechanisms may mediate the effects of social interactions on individual remembering and how they may serve social information transmission and the formation of socially shared memories.

Shared vivid remembering: age-related differences in across-participants similarity of neural representations during encoding and retrieval.

Recent advances in multivariate neuroimaging analyses have made possible the examination of the similarity of the neural patterns of activations measured across participants, but it has not been investigated yet whether such measure is age-sensitive. Here, in the scanner, young and older participants viewed scene pictures associated with labels. At test, participants were presented with the labels and were asked to recollect the associated picture. We used Pattern Similarity Analyses by which we compared patterns of neural activation during the encoding or the remembering of each picture of one participant with the averaged pattern of activation across the remaining participants. Results revealed that across-participants neural similarity was higher in young than in older adults in distributed occipital, temporal and parietal areas during encoding and retrieval. These findings demonstrate that an age-related reduction in specificity of neural activation is also evident when the similarity of neural representations is examined across participants.

Modularity-based parallel protein design algorithm with an implementation using shared memory programming.

Given a target protein structure, the prime objective of protein design is to find amino acid sequences that will fold/acquire to the given three-dimensional structure. The protein design problem belongs to the non-deterministic polynomial-time-hard class as sequence search space increases exponentially with protein length. To ensure better search space exploration and faster convergence, we propose a protein modularity-based parallel protein design algorithm. The modular architecture of the protein structure is exploited by considering an intermediate structural organization between secondary structure and domain defined as protein unit (PU). Here, we have incorporated a divide-and-conquer approach where a protein is split into PUs and each PU region is explored in a parallel fashion. It has been further analyzed that our shared memory implementation of modularity-based parallel sequence search leads to better search space exploration compared to the case of traditional full protein design. Sequence-based analysis on design sequences depicts an average of 39.7% sequence similarity on the benchmark data set. Structure-based comparison of the modeled structures of the design protein with the target structure exhibited an average root-mean-square deviation of 1.17 Å and an average template modeling score of 0.89. The selected modeled structures of the design protein sequences are validated using 100 ns molecular dynamics simulations where 80% of the proteins have shown better or similar stability to the respective target proteins. Our study informs that our modularity-based protein design algorithm can be extended to protein interaction design as well.

Does a Sense of Social Presence During Conversation Affect Student's Shared Memory? Evidence From SS-RIF Paradigm.

People constantly talk to one another about the past, and in so doing, they recount certain details while remaining silent about others. Collaborative or conversational remembering plays an important role in establishing shared representations of the past (e.g., the 911 attacks, Covid-19). According to the socially shared retrieval-induced forgetting (SS-RIF) effect, a listener will forget about relevant but unpracticed information during communication, due to intentional or unintentional selective retrieval of data by the speaker. The SS-RIF paradigm has been applied to explain how collective memory is shaped within the context of conversation/discourse. This study sought to determine if SS-RIF occurred only during face-to-face communication, or whether shared memories could be developed through other types of conversation quite common in modern society. We also investigated whether a level of social interaction in the real-world presence of others is a necessary condition for inducing SS-RIF, and if listeners experience different degrees of SS-RIF due to different levels of perceived social presence. We observed the SS-RIF phenomenon in listeners both in real life and video; the degree of forgetting was the same for the two conditions. These results indicate that social presence may not be associated with SS-RIF. Public silence affects the formation of collective memory regardless of the face-to-face presence of others, and thus physical presence is not necessary to induce SS-RIF.

Shared event memory in aging: Across-participants similarity of vividness judgements decreases with age.

When they remember the same events, humans recollect common episodic traces. For making vividness judgements, older adults rely less than young adults on retrieved episodic details. Here, we examined the similarity of the subjective experience of remembering and the associated memory content across participants and we investigated age-effects. Young and older adults studied pictures associated with labels. At retrieval, participants judged the vividness of their memories and recalled pictures details. We examined the similarity of vividness judgements and memory recall across-participants. Across-participants similarity in vividness judgements was higher in young than in older adults, while no age-difference in the similarity of the richness of memory recall between participants was found. Together, these findings suggest that older adults' vividness ratings are less similar from one participant to another than those of young adults, which may be explained by how older adults use memory details to frame their sense of memory vividness.

Optimization and parallelization of the discrete ordinate method for radiation transport simulation in OpenFOAM: Hierarchical combination of shared and distributed memory approaches.

This paper describes the reduction in memory and computational time for the simulation of complex radiation transport problems with the discrete ordinate method (DOM) model in the open-source computational fluid dynamics platform OpenFOAM. Finite volume models require storage of vector variables in each spatial cell; DOM introduces two additional discretizations, in direction and wavelength, making memory a limiting factor. Using specific classes for radiation sources data, changing the store of fluxes and other minor changes allowed a reduction of 75% in memory requirements. Besides, a hierarchical parallelization was developed, where each node of the standard parallelization uses several computing threads, allowing higher speed and scalability of the problem. This architecture, combined with optimization of some parts of the code, allowed a global speedup of x15. This relevant reduction in time and memory of radiation transport opens a new horizon of applications previously unaffordable.

Time-energy measured data on modern multicore systems running shared-memory applications.

This article presents execution time and energy data collected from modern multicore systems running shared-memory applications, analyzed using our analytic models. While the full data sets and source code are available on Github, this data-in-brief article includes some samples and describes the experimental setup.

A multi-core ready discrete element method with triangles using dynamically adaptive multiscale grids.

The simulation of vast numbers of rigid bodies of non-analytical shapes and of tremendously different sizes that collide with each other is computationally challenging. A bottleneck is the identification of all particle contact points per time step. We propose a tree-based multilevel meta data structure to administer the particles. The data structure plus a purpose-made tree traversal identifying the contact points introduce concurrency to the particle comparisons, whilst they keep the absolute number of particle-to-particle comparisons low. Furthermore, a novel adaptivity criterion allows explicit time stepping to work with comparably large time steps. It optimises both toward low algorithmic complexity per time step and low numbers of time steps. We study three different parallelisation strategies exploiting our traversal's concurrency. The fusion of two of them yields promising speedups once we rely on maximally asynchronous task-based realisations. Our work shows that new computer architecture can push the boundary of rigid particle computability, yet if and only if the right data structures and data processing schemes are chosen.

Interdomain I/O Optimization in Virtualized Sensor Networks.

In virtualized sensor networks, virtual machines (VMs) share the same hardware for sensing service consolidation and saving power. For those VMs that reside in the same hardware, frequent interdomain data transfers are invoked for data analytics, and sensor collaboration and actuation. Traditional ways of interdomain communications are based on virtual network interfaces of bilateral VMs for data sending and receiving. Since these network communications use TCP/IP (Transmission Control Protocol/Internet Protocol) stacks, they result in lengthy communication paths and frequent kernel interactions, which deteriorate the I/O (Input/Output) performance of involved VMs. In this paper, we propose an optimized interdomain communication approach based on shared memory to improve the interdomain communication performance of multiple VMs residing in the same sensor hardware. In our approach, the sending data are shared in memory pages maintained by the hypervisor, and the data are not transferred through the virtual network interface via a TCP/IP stack. To avoid security trapping, the shared data are mapped in the user space of each VM involved in the communication, therefore reducing tedious system calls and frequent kernel context switches. In implementation, the shared memory is created by a customized shared-device kernel module that has bidirectional event channels between both communicating VMs. For performance optimization, we use state flags in a circular buffer to reduce wait-and-notify operations and system calls during communications. Experimental results show that our proposed approach can provide five times higher throughput and 2.5 times less latency than traditional TCP/IP communication via a virtual network interface.

Enabling large-scale next-generation sequence assembly with Blacklight.

A variety of extremely challenging biological sequence analyses were conducted on the XSEDE large shared memory resource Blacklight, using current bioinformatics tools and encompassing a wide range of scientific applications. These include genomic sequence assembly, very large metagenomic sequence assembly, transcriptome assembly, and sequencing error correction. The data sets used in these analyses included uncategorized fungal species, reference microbial data, very large soil and human gut microbiome sequence data, and primate transcriptomes, composed of both short-read and long-read sequence data. A new parallel command execution program was developed on the Blacklight resource to handle some of these analyses. These results, initially reported previously at XSEDE13 and expanded here, represent significant advances for their respective scientific communities. The breadth and depth of the results achieved demonstrate the ease of use, versatility, and unique capabilities of the Blacklight XSEDE resource for scientific analysis of genomic and transcriptomic sequence data, and the power of these resources, together with XSEDE support, in meeting the most challenging scientific problems.

Fast decision tree-based method to index large DNA-protein sequence databases using hybrid distributed-shared memory programming model.

In recent times, the size of biological databases has increased significantly, with the continuous growth in the number of users and rate of queries; such that some databases have reached the terabyte size. There is therefore, the increasing need to access databases at the fastest rates possible. In this paper, the decision tree indexing model (PDTIM) was parallelised, using a hybrid of distributed and shared memory on resident database; with horizontal and vertical growth through Message Passing Interface (MPI) and POSIX Thread (PThread), to accelerate the index building time. The PDTIM was implemented using 1, 2, 4 and 5 processors on 1, 2, 3 and 4 threads respectively. The results show that the hybrid technique improved the speedup, compared to a sequential version. It could be concluded from results that the proposed PDTIM is appropriate for large data sets, in terms of index building time.

A FAST ITERATIVE METHOD FOR SOLVING THE EIKONAL EQUATION ON TETRAHEDRAL DOMAINS.

Generating numerical solutions to the eikonal equation and its many variations has a broad range of applications in both the natural and computational sciences. Efficient solvers on cutting-edge, parallel architectures require new algorithms that may not be theoretically optimal, but that are designed to allow asynchronous solution updates and have limited memory access patterns. This paper presents a parallel algorithm for solving the eikonal equation on fully unstructured tetrahedral meshes. The method is appropriate for the type of fine-grained parallelism found on modern massively-SIMD architectures such as graphics processors and takes into account the particular constraints and capabilities of these computing platforms. This work builds on previous work for solving these equations on triangle meshes; in this paper we adapt and extend previous two-dimensional strategies to accommodate three-dimensional, unstructured, tetrahedralized domains. These new developments include a local update strategy with data compaction for tetrahedral meshes that provides solutions on both serial and parallel architectures, with a generalization to inhomogeneous, anisotropic speed functions. We also propose two new update schemes, specialized to mitigate the natural data increase observed when moving to three dimensions, and the data structures necessary for efficiently mapping data to parallel SIMD processors in a way that maintains computational density. Finally, we present descriptions of the implementations for a single CPU, as well as multicore CPUs with shared memory and SIMD architectures, with comparative results against state-of-the-art eikonal solvers.

Função fraterna: reflexões a partir do filme Príncipe das Marés / Fraternal function: reflections based on the movie The prince of tides / Función fraterna: reflexiones a partir de la película Príncipe de las marés

Somente a partir do século XXI surge um interesse maior pelo estudo da fratria na área da Psicologia. Neste trabalho, propõe-se desenvolver um estudo teórico na perspectiva psicanalítica, buscando analisar a importância da relação fraterna na estruturação do psiquismo do sujeito e a relevância da presença do irmão no compartilhamento de uma história comum ao longo da vida. São utilizados os conceitos de autores clássicos, como Freud e Lacan, e ainda de outros teóricos contemporâneos, como Kaës, Kancyper e Kehl. Para complementar a discussão, analisa-se a relação entre os irmãos, retratada no filme intitulado "Príncipe das marés", no qual um irmão-gêmeo é convidado a ajudar no tratamento do quadro depressivo da sua irmã, a partir do resgate de sua memória e história de vida.

It is only in the 21 st century that emerges the interest in studying brotherhood in the field of Psychology. The goal of the present work is to develop a theoretical study, from a psychoanalytic perspective, analyzing the importance of fraternal relationships in the structuring of subjects' psyche and the relevance of siblings' presence in sharing common stories throughout life. We adopt concepts from classical authors, such as Freud and Lacan, as well as other contemporary authors such as Kaës, Kancyper e Kehl. In order to complement the discussion, we analyze the siblings' relationship portrayed in the movie "The Prince of Tides", in which a man is requested to participate in the treatment of her depressive twin sister, rescuing her memory and life history.

Solamente a partir del siglo XXI surge un interés mayor por el estudio de la fratria en la área de la Psicología. En este trabajo, se propone desarollar un estudio teórico en la perspectiva psicoanalítica, buscando analisar la importancia de la relación fraterna en la estructuración del psiquismo del sujeto y la relevancia de la presencia del hermano en el compartimiento de una historia común, al largo de la vida. Son utilizados los conceptos de autores clásicos como Freud y Lacan y aún otros autores contemporâneos, como Kaës, Kancyper e Kehl. Para complementar la discusión, se analisa la relación entre los hermanos, retratada en la película intitulada "Príncipe das Marés", en la cual uno de los hermanos gemelos es invitado a ayudar en el tratamiento del cuadro depresivo de su hermana, a partir del rescate de su memoria e historia de vida.

Função fraterna: reflexões a partir do filme Príncipe das Marés / Fraternal function: reflections based on the movie The prince of tides / Función fraterna: reflexiones a partir de la película Príncipe de las marés

Somente a partir do século XXI surge um interesse maior pelo estudo da fratria na área da Psicologia. Neste trabalho, propõe-se desenvolver um estudo teórico na perspectiva psicanalítica, buscando analisar a importância da relação fraterna na estruturação do psiquismo do sujeito e a relevância da presença do irmão no compartilhamento de uma história comum ao longo da vida. São utilizados os conceitos de autores clássicos, como Freud e Lacan, e ainda de outros teóricos contemporâneos, como Kaës, Kancyper e Kehl. Para complementar a discussão, analisa-se a relação entre os irmãos, retratada no filme intitulado "Príncipe das marés", no qual um irmão-gêmeo é convidado a ajudar no tratamento do quadro depressivo da sua irmã, a partir do resgate de sua memória e história de vida(AU)

It is only in the 21 st century that emerges the interest in studying brotherhood in the field of Psychology. The goal of the present work is to develop a theoretical study, from a psychoanalytic perspective, analyzing the importance of fraternal relationships in the structuring of subjects' psyche and the relevance of siblings' presence in sharing common stories throughout life. We adopt concepts from classical authors, such as Freud and Lacan, as well as other contemporary authors such as Kaës, Kancyper e Kehl. In order to complement the discussion, we analyze the siblings' relationship portrayed in the movie "The Prince of Tides", in which a man is requested to participate in the treatment of her depressive twin sister, rescuing her memory and life history(AU)

Solamente a partir del siglo XXI surge un interés mayor por el estudio de la fratria en la área de la Psicología. En este trabajo, se propone desarollar un estudio teórico en la perspectiva psicoanalítica, buscando analisar la importancia de la relación fraterna en la estructuración del psiquismo del sujeto y la relevancia de la presencia del hermano en el compartimiento de una historia común, al largo de la vida. Son utilizados los conceptos de autores clásicos como Freud y Lacan y aún otros autores contemporâneos, como Kaës, Kancyper e Kehl. Para complementar la discusión, se analisa la relación entre los hermanos, retratada en la película intitulada "Príncipe das Marés", en la cual uno de los hermanos gemelos es invitado a ayudar en el tratamiento del cuadro depresivo de su hermana, a partir del rescate de su memoria e historia de vida(AU)