Persistent Representation Research Articles

Teachers’ perspectives on determinants of educational (under)achievement of Cigano/Roma students in Portugal

ABSTRACT The presence of Cigano/Roma students in secondary education in Portugal is still a rarity, considering that less than 3% of young Ciganos/Roma attend secondary education. This article aims to highlight the need for a comprehensive understanding of the perceptions of school teachers and principals on educational (under)achievement, absenteeism and school integration of Cigano students. To this end, we analyse data from an online questionnaire survey of a sample of 819 teachers, school principals and deputy principals and other senior management staff in schools of the Metropolitan Areas. These respondents express persistent representations and stereotypes in relation to the educational trajectories of Cigano students, especially in assigning prime causes of school failure to factors relating to the students’ family or own intrinsic issues, rarely indicating institutional factors or those linked to their teaching practices. Although this is a study centred on Portugal, the lessons drawn from it can point to new directions for other contexts, as the educational achievement of Cigano students represents an opportunity and an invitation to transform and upgrade school institutions as well as the educational system as a whole, which should be more innovative, reflexive and increasingly open to the community.

Event-specific and persistent representations for contextual states in orbitofrontal neurons

Flexible and context-dependent behaviors require animals, including humans, to identify their current contextual state for proper rules to apply, especially when information that defines these states is partially observable. Depending on behavioral needs, contextual states usually persist for prolonged periods and across other events, including sensory stimuli, actions, and rewards, highlighting prominent challenges of holding a reliable state representation. The orbitofrontal cortex (OFC) is crucial in behaviors requiring the identification of the current context (e.g., reversal learning); however, how single units in the OFC accomplish this function has not been assessed. Do they maintain such information persistently, in separate populations from those responding phasically to events within a task, or is contextual information dynamic and embedded in these phasic responses? Here, we investigated this question by recording single units from OFC in rats performing a task that required them to identify the current contextual state related to estimated proximity to future reward with distracting olfactory cues. We found that while some OFC neurons encode contextual states, most change their selectivity upon the transition of task events. Nevertheless, despite dynamic activities in single neurons, the neural populations maintain persistent representations regarding current contextual states within particular neural subspaces.

Foundations of spatial perception for robotics: Hierarchical representations and real-time systems

3D spatial perception is the problem of building and maintaining an actionable and persistent representation of the environment in real-time using sensor data and prior knowledge. Despite the fast-paced progress in robot perception, most existing methods either build purely geometric maps (as in traditional SLAM) or “flat” metric-semantic maps that do not scale to large environments or large dictionaries of semantic labels. The first part of this paper is concerned with representations: we show that scalable representations for spatial perception need to be hierarchical in nature. Hierarchical representations are efficient to store, and lead to layered graphs with small treewidth, which enable provably efficient inference. We then introduce an example of hierarchical representation for indoor environments, namely a 3D scene graph, and discuss its structure and properties. The second part of the paper focuses on algorithms to incrementally construct a 3D scene graph as the robot explores the environment. Our algorithms combine 3D geometry (e.g., to cluster the free space into a graph of places), topology (to cluster the places into rooms), and geometric deep learning (e.g., to classify the type of rooms the robot is moving across). The third part of the paper focuses on algorithms to maintain and correct 3D scene graphs during long-term operation. We propose hierarchical descriptors for loop closure detection and describe how to correct a scene graph in response to loop closures, by solving a 3D scene graph optimization problem. We conclude the paper by combining the proposed perception algorithms into Hydra, a real-time spatial perception system that builds a 3D scene graph from visual-inertial data in real-time. We showcase Hydra’s performance in photo-realistic simulations and real data collected by a Clearpath Jackal robots and a Unitree A1 robot. We release an open-source implementation of Hydra at https://github.com/MIT-SPARK/Hydra.

A Framework for a Persistent Representation of Customer Knowledge to Enhance Product Development

A Framework for a Persistent Representation of Customer Knowledge to Enhance Product Development

Persistent racialized commodification amidst technological innovation: exceptionalist Filipina bride representations from analog to digital

ABSTRACT Available internet research focus on the linear transition from Web1.0 to Web3.0 without realizing their interplay across platforms and interactions with analog and real-world. Such interactions are examined in the foreign bride trade industry’s shifting and stable discursive representations of Filipino women as the industry moved from analog print catalogues to static, unidirectional Web1.0, multidirectional Web2.0 and decentralized Web3.0. Technological changes have transformed digital platforms and information delivery and continued marketable representations of Filipina brides’ racialized exceptionalisms. Shifting from analog to digital platforms has simultaneously disrupted and preserved gendered-racialized hierarchical representations of Filipina brides as simultaneously paradoxical, problematic, and provocative variations in purveying Philippine postcolonial exceptionalism. Critical discourse analyses of sample catalogues and Web1.0–2.0 websites reveal three persistent exceptionalism variants in Filipina bride representations—extraordinary, comparative, and pragmatic—reproducing racialized-sexualized desires and hierarchies, which endured across technological platforms, simultaneously reproducing and disrupting persistent representations of foreign brides from the Global South, particularly Filipinas.

The new GeoModel suite, a lightweight detector description and visualization toolkit for HEP

The GeoModel toolkit is an open-source suite of standalone tools that provides the user with lightweight tools to describe, visualize, test, and debug detector descriptions and geometries for HEP standalone studies and experiments. GeoModel has been designed with independence and responsiveness in mind and offers a development environment free of other large HEP tools and frameworks, and with a very quick development cycle. With very few and lightweight dependencies, GeoModel is easy to install on all systems, in a modular way; and pre-compiled binaries are provided for the major platforms, for a quick and easy installation. Coded entirely in C++, GeoModel offers the user tools to describe geometries inside C++ code or in external XML files, create persistent representation with a low disk footprint and interactively visualize and inspect the geometry in a 3D view. It also offers a plugin mechanism and an optional Geant4 application to simulate the described geometry in a standalone environment. GeoModel has been developed as part of the software for the ATLAS experiment at the LHC, and evolved towards an experiment-independent toolkit. In this contribution, we describe all the available tools, with a focus on the latest additions, which provide users with more visualization, debug, and simulation tools.

Persistent representation of the environment in the hippocampus

In the hippocampus, environmental changes elicit rearrangement of active neuronal ensembles or remapping of place cells. However, it remains elusive how the brain ensures a consistent representation of a certain environment itself despite salient events occurring there. Here, we longitudinally tracked calcium dynamics of dorsal hippocampal CA1 neurons in mice subjected to contextual fear conditioning and extinction training. Overall population activities were significantly changed by fear conditioning and were responsive to footshocks and freezing. However, a small subset of neurons, termed environment cells, were consistently active in a specific environment irrespective of experiences. A decoder modeling study showed that these cells, but not place cells, were able to predict the environment to which the mouse was exposed. Environment cells might underlie the constancy of cognition for distinct environments across time and events. Additionally, our study highlights the functional heterogeneity of cells in the hippocampus.

Charles Macklin and the Theatres of London

Charles Macklin and the Theatres of London

Records, trust, and misinformation: Using birtherism to understand the influence of conspiracy theories on human information interactions

AbstractRecords are persistent representations of activities created by partakers, observers, or their authorized proxies. People are generally willing to trust vital records such as birth, death, and marriage certificates. However, conspiracy theories and other misinformation may negatively impact perceptions of such documents, particularly when they are associated with a significant person or event. This paper explores the relationship between archival records and trustworthiness by reporting results of a survey that asked genealogists about their perceptions of 44th U.S. President Barack Obama's birth certificate, which was then at the center of the “birtherism” conspiracy. We found that although most participants perceived the birth certificate as trustworthy, others engaged in a biased review, considering it not trustworthy because of the news and politics surrounding it. These findings suggest that a conspiracy theory can act as a moderating variable that undermines the efficacy of normal or recommended practices and procedures for evaluating online information such as birth certificates. We provide recommendations and propose strategies for archivists to disseminate correct information to counteract the spread of misinformation about the authenticity of vital records, and we discuss future directions for research.

Defining Conjunto Quantitatively: Classical and Modernist Styles in a Texas-Mexican Genre

Defining <i>Conjunto</i> Quantitatively: Classical and Modernist Styles in a Texas-Mexican Genre

Record-Making and Record-Keeping in Early Societies

Record-Making and Record-Keeping in Early Societies

Extended Frontal Networks for Visual and Auditory Working Memory.

Working memory (WM) supports the persistent representation of transient sensory information. Visual and auditory stimuli place different demands on WM and recruit different brain networks. Separate auditory- and visual-biased WM networks extend into the frontal lobes, but several challenges confront attempts to parcellate human frontal cortex, including fine-grained organization and between-subject variability. Here, we use differential intrinsic functional connectivity from 2 visual-biased and 2 auditory-biased frontal structures to identify additional candidate sensory-biased regions in frontal cortex. We then examine direct contrasts of task functional magnetic resonance imaging during visual versus auditory 2-back WM to validate those candidate regions. Three visual-biased and 5 auditory-biased regions are robustly activated bilaterally in the frontal lobes of individual subjects (N = 14, 7 women). These regions exhibit a sensory preference during passive exposure to task stimuli, and that preference is stronger during WM. Hierarchical clustering analysis of intrinsic connectivity among novel and previously identified bilateral sensory-biased regions confirms that they functionally segregate into visual and auditory networks, even though the networks are anatomically interdigitated. We also observe that the frontotemporal auditory WM network is highly selective and exhibits strong functional connectivity to structures serving non-WM functions, while the frontoparietal visual WM network hierarchically merges into the multiple-demand cognitive system.

Role of verbal working memory in rapid procedural acquisition of a choice response task

How quickly are instructions for a task translated into an effective task-set? If declarative working memory (dWM) is used to maintain a task's S-R rules until practice compiles them adequately into procedural memory, variables that affect retrieval from dWM should influence task performance while it is still dependent on dWM. Participants were trained on a series of 6-choice RT tasks, with a 1:1 mapping from object pictures to keys. In Experiments 1 and 2, an instruction phase — presentation of the S-R rules one by one —was followed by test trials. The phonological similarity of the objects' names significantly affected performance only during the first few encounters with the stimuli. Serial position effects were also consistent with retrieval from verbal dWM during those early trials. In Experiment 3, instruction onon the S-R rules was omitted, so participants had to learn the S-R mappings by trial and error alone; the effect of phonological similarity lasted longer, but still disappeared after a dozen encounters with each stimulus. Experiment 4 showed that instructions and just four trials of practice per S-R rule were sufficient to form a persisting representation of the S-R rules robust enough to interfere with later acquisition of a competing S-R rule after several minutes spent acquiring other task-sets. An effective and lasting task-set is rapidly compiled into procedural memory through instruction and early feedback; verbal dWM plays little role thereafter.

Digital records as relational objects–Yuk Hui’s concept of digital objects applied to archival science

The writings of Yuk Hui, bringing together both technical and philosophical insights, present a new way of dealing with the digital. The aim of this article is to assess the use of Hui’s theories on digital objects as a critical reframing, looking at the concept of digital records in particular. Two types of ontology are needed in order to understand digital objects according to Hui: (1) ontologies which relates to the technical language and hierarchies of knowledge representation, like metadata; (2) Ontology, which is a question of being-in-the-tradition of Heidegger’s phenomenology, the understanding of what it is to be in the world. Both are needed to account for the nature of the digital object. Further, digital objects are produced and constituted through their relations, which can be divided into discursive (technical and logical) and existential (the understanding of being-in-the-world) relations. Different conceptions of digital records are discussed, in order to find commonalities and possibilities in relation to Hui’s theory. The digital record as a process of becoming, information as affordance, and temporality are related to and structured through the application of Hui’s perspective. The article ends with the contribution of a possible redefinition of digital records: a digital record is constituted and concretised as material by discursive and existential relations that taken together function as a persistent representation. Hui’s theory is suggested as a set of coordinates for further thinking and a method for critical reading of digital records.

Neurophysiological models of phantom limb pain: what can be learnt

Phantom Limb Pain (PLP) is a dysesthesic painful sensations perceived in the lost limb, resulting from complex interactions between structural and functional nervous systems changes. We analyze its main pathogenetic models and speculate on candidate therapeutic targets. The neuroma model considers PLP to arise from spontaneous activity of residual limb injured axons. Other peripheral-origin models attribute PLP to damage of somatosensory receptors or vascular changes. According to the cortical remapping model, the loss of bidirectional nervous flow and the need to enhance alternative functions trigger reorganization and arm and face skin afferents "invade" the hand territory. On the contrary, the persistent representation model suggests that continued inputs preserve the lost limb representation and that, instead to a shrinkage, PLP is associated with larger representation and stronger cortical activity. In the neuromatrix model, the mismatch between body representation, which remains intact despite limb amputation, and real body appearance generates pain. Another hypothesis is that proprioceptive memories associate specific limb positions with pre-amputation pain and may be recalled by those positions. Finally, the stochastic entanglement model offers a direct relationship between sensorimotor neural reorganization and pain. Amputation disrupts motor and somatosensory circuits, allowing for maladaptive wiring with pain circuits and causing pain without nociception. Relief of PLP depends solely on motor and somatosensory circuitry engagement, making anthropomorphic visual feedback dispensable. Existing and apparently contradicting theories might not be mutually exclusive. All of them involve several intertwined potential mechanisms by which replacing the amputated limb by an artificial one could counteract PLP.

The GeoModel tool suite for detector description

The GeoModel class library for detector description has recently been released as an open-source package and extended with a set of tools to allow much of the detector modeling to be carried out in a lightweight development environment, outside of large and complex software frameworks. These tools include the mechanisms for creating persistent representation of the geometry, an interactive 3D visualization tool, various command-line tools, a plugin system, and XML and JSON parsers. The overall goal of the tool suite is a fast geometry development cycle with quick visual feedback. The tool suite can be built on both Linux and Macintosh systems with minimal external dependencies. It includes useful command-line utilities: gmclash which runs clash detection, gmgeantino which generates geantino maps, and fullSimLight which runs GEANT4 simulation on geometry imported from GeoModel description. The GeoModel tool suite is presently in use in both the ATLAS and FASER experiments. In ATLAS it will be the basis of the LHC Run 4 geometry description.

The homeostatic homunculus: rethinking deprivation-triggered reorganisation.

While amputation was considered a prominent model for cortical reorganisation, recent evidence highlights persistent representation of the missing hand. We offer a new perspective on the literature of amputation-triggered sensorimotor plasticity, by emphasising the need for homeostasis and emerging evidence of latent activity distributed across the homunculus. We argue that deprivation uncovers pre-existing latent activity, which can manifest as remapping, but that since this activity was already there, remapping could in some instances correspond to functional stability of the system rather than reorganisation. Adaptive behaviour and Hebbian-like plasticity may also play crucial roles in maintaining the functional organisation of the homunculus when deprivation occurs in adulthood or in early development. Collectively, we suggest that the brain's need for stability may underlie several key phenotypes for brain remapping, previously interpreted as consequential to reorganisation. Nevertheless, reorganisation may still be possible, especially when cortical changes contribute to the stability of the system.

Prior Cocaine Use Alters the Normal Evolution of Information Coding in Striatal Ensembles during Value-Guided Decision-Making.

Substance use disorders (SUDs) are characterized by maladaptive behavior. The ability to properly adjust behavior according to changes in environmental contingencies necessitates the interlacing of existing memories with updated information. This can be achieved by assigning learning in different contexts to compartmentalized "states." Though not often framed this way, the maladaptive behavior observed in individuals with SUDs may result from a failure to properly encode states because of drug-induced neural alterations. Previous studies found that the dorsomedial striatum (DMS) is important for behavioral flexibility and state encoding, suggesting the DMS may be an important substrate for these effects. Here, we recorded DMS neural activity in cocaine-experienced male rats during a decision-making task where blocks of trials represented distinct states to probe whether the encoding of state and state-related information is affected by prior drug exposure. We found that DMS medium spiny neurons (MSNs) and fast-spiking interneurons (FSIs) encoded such information and that prior cocaine experience disrupted the evolution of representations both within trials and across recording sessions. Specifically, DMS MSNs and FSIs from cocaine-experienced rats demonstrated higher classification accuracy of trial-specific rules, defined by response direction and value, compared with those drawn from sucrose-experienced rats, and these overly strengthened trial-type representations were related to slower switching behavior and reaction times. These data show that prior cocaine experience paradoxically increases the encoding of state-specific information and rules in the DMS and suggest a model in which abnormally specific and persistent representation of rules throughout trials in DMS slows value-based decision-making in well trained subjects.SIGNIFICANCE STATEMENT Substance use disorders (SUDs) may result from a failure to properly encode rules guiding situationally appropriate behavior. The dorsomedial striatum (DMS) is thought to be important for such behavioral flexibility and encoding that defines the situation or "state." This suggests that the DMS may be an important substrate for the maladaptive behavior observed in SUDs. In the current study, we show that prior cocaine experience results in over-encoding of state-specific information and rules in the DMS, which may impair normal adaptive decision-making in the task, akin to what is observed in SUDs.

The rhythmicity of daily travel: young children’s mobility practices along the mobile preschool route

ABSTRACT The article aims to highlight the means of rhythmicity to social life from within a study of children’s daily travelling with a mobile preschool in Sweden. The point of departure is the neglected mobility practices of young children in research and the difficult relation between children’s everyday movements and persistent representations of childhood time and place. Based on sensuous ethnographic fieldwork travelling with the preschool, the analysis deconstructs to visualize mobility modes at work in the enactment of the daily route, and explores to highlight the preschooler’s collective rhythms of practices while travelling. The rhythmanalysis shows how regular mobilities enable shared experiences and the (re)making of a rhythmicity grounded in an ongoing perceiving and managing of inside and outside rhythms. The result confirms young children’s interdependent mobilities from within an entanglement of different rhythms, and contributes with readings of how they ‘carry on’ in practice.

Issues and Changes Related to Dissonant Heritage: a Case from Jewish and Polish Heritage in the Small Towns of Western Ukraine

ABSTRACT This study presents and analyzes the cases of “dissonant heritage” issues in areas characterized by multicultural backgrounds and conflicting historical narratives. Contrasting trends, which include persistent or resurgent one-sided nationalistic representations, as well as more inclusive and plural emerging trends in heritage promotion, are compared and discussed through the example of three selected towns located in Western Ukraine. The three towns were selected among others as representative of formerly multiethnic communities now turned into ethnically homogeneous ones, where minority heritage shows different degrees of neglect or promotion, in order to understand which aspects of history, memory, and heritage have been selected and promoted or not, and why. The study results show the rise of inclusive narratives in which minority heritage, with the related historical memories, rather than a menace for national cohesion, can become a solid opportunity for local development and for cultural, social, and political pluralism in marginal areas.