In 1990 J-L. Krivine introduced the notion of storage operators. They are $\lambda$ -terms which simulate call-by-value in the call-by-name strategy and they can be used in order to modelize assignment instructions. J-L. Krivine has shown that there is a very simple second order type in AF2 type system for storage operators using Gödel translation of classical to intuitionistic logic. In order to modelize the control operators, J-L. Krivine has extended the system AF2 to the classical logic. In (...) his system the property of the unicity of integers representation is lost, but he has shown that storage operators typable in the system AF2 can be used to find the values of classical integers. In this paper, we present a new classical type system based on a logical system called mixed logic. We prove that in this system we can characterize, by types, the storage operators and the control operators. (shrink)

Most cognitive scientists believe that cognitive processing (e.g., thought, speech, perception, and sensori‐motor processing) is the hallmark of intelligent systems. Aside from modeling such processes, cognitive science is in the business of mechanistically explaining how minds and other intelligent systems work. As one might expect, mechanistic explanations appeal to the causal‐functional interactions among a system's component structures. Good explanations are the ones that get the causal story right. But getting the causal story right requires positing structures that are really in (...) the system. After all, within the context of a mechanistic explanation, to posit X is to claim not only that X exists but that X is doing some causal labor. Because most cognitive scientists believe that cognitive processing requires the use, manipulation, and storage of internal representations, they characteristically posit internal representations to explain how intelligent systems work. (shrink)

The importance of working memory in reading and mathematics performance has been widely studied, with recent research examining the components of WM and their roles in these educational outcomes. However, the differing relationships between these abilities and the foundational skills involved in the development of reading and mathematics have received less attention. Additionally, the separation of verbal, visual and spatial storage and processing and subsequent links with foundational skills and downstream reading and mathematics has not been widely examined. The (...) current study investigated the separate contributions of processing and storage from verbal, visual and spatial tasks to reading and mathematics, whilst considering influences on the underlying skills of verbal comprehension and counting, respectively. Ninety-two children aged 7- to 8-years were assessed. It was found that verbal comprehension was predicted by verbal storage and reading was predicted by verbal and spatial storage. Counting was predicted by visual processing and storage, whilst mathematics was related to verbal and spatial storage. We argue that resources for tasks relying on external representations of stimuli related mainly to storage, and were largely verbal and spatial in nature. When a task required internal representation, there was a draw on visual processing and storage abilities. Findings suggest a possible meaningful separability of types of processing. Further investigation of this could lead to the development of an enhanced WM model, which might better inform interventions and reasonable adjustments for children who struggle with reading and mathematics due to WM deficits. (shrink)

Hybrid and pluralist accounts of concepts agree that the class of concepts includes a multiplicity of heterogeneous representational structures, such as prototypes, sets of exemplars and theories. In this paper I argue that these accounts agree on two additional central claims related to the ways in which they articulate those structures: each type of representational structure can be used independently in psychological processes, and co-referential concepts are associated in a distinctive way as representations of the same category. Although they disagree (...) on concept individuation, they seem to agree that on a processing dimension there are multiple independent representations for a given category and on a long-term storage dimension concepts that represent the same category conform an epistemic unity. (shrink)

Phillips & Silverstein emphasize the gain-control properties of NMDA synapses in cognitive coordination. We endorse their view and suggest that NMDA synapses play a crucial role in biased attentional competition and (visual) working memory. Our simulations show that NMDA synapses can control the storage rate of visual objects. We discuss specific predictions of our model about cognitive effects of NMDA-antagonists and schizophrenia.

MKM has been defined as the quest for technologies to manage mathematical knowledge. MKM “in the small” is well-studied, so the real problem is to scale up to large, highly interconnected corpora: “MKM in the large”. We contend that advances in two areas are needed to reach this goal. We need representation languages that support incremental processing of all primitive MKM operations, and we need software architectures and implementations that implement these operations scalably on large knowledge bases. We present (...) instances of both in this paper: the MMT framework for modular theory-graphs that integrates meta-logical foundations, which forms the base of the next OMDOC version; and TNTBase, a versioned storage system for XML- based document formats. TNTBase becomes an MMT database by instantiating it with special MKM operations for MMT. (shrink)

The storage operators were introduced by J.L. Krivine ([6]); they are closed λ-terms which, for some fixed data type (the integers for example), allow to simulate “call by value” while using “call by name”. J.L. Krivine showed that such operators can be typed, in the type system, using Gödel's translation from classical to intuitionistic logic ([8]).This paper studies the existence of storage operators which give a normal form as result (strong storage operators) for recursive and iterative (...) class='Hi'>representation of data in λ-calculus. We obtain the following result:We can find typed strong storage operators for the recursive representations of data type, but that is not the case for the iterative representations of an infinite data type.We give the proof of this result in the case of integers. (shrink)

Neuroimaging evidence suggests that the left inferior frontal gyrus (LIFG) supports temporary storage of linguistic material during linguistic tasks rather than computing a syntactic representation. The LIFG is not activated by simple sentences but by complex sentences and maintenance of word lists. Under this hypothesis, agrammatism should only disturb comprehension for constructions in which storage is essential.

The notion of a "mental representation" is, arguably, in the first instance a theoretical construct of cognitive science. As such, it is a basic concept of the Computational Theory of Mind, according to which cognitive states and processes are constituted by the occurrence, transformation and storage (in the mind/brain) of information-bearing structures (representations) of one kind or another.

This paper takes an evolutionary approach to what we are, namely autopoietic systems with a first person perspective on our surroundings and ourselves. This in contrast with Thomas Metzinger.

Commentators expressed a wide variety of views on whether there is a basic capacity limit of 3 to 5 chunks and, among those who believe in it, about why it occurs. In this response, I conclude that the capacity limit is real and that the concept is strengthened by additional evidence offered by a number of commentators. I consider various arguments why the limit occurs and try to organize these arguments into a conceptual framework or “metatheory” of storage capacity (...) limits meant to be useful in future research to settle the issue. I suggest that principles of memory representation determine what parts of the representation will be most prominent but that limits of attention (or of a memory store that includes only items that have been most recently attended) determine the 3- to 5-chunk capacity limit. (shrink)

There is an ongoing debate about the meaning of lexical words, i.e., words that contribute with content to the meaning of sentences. This debate has coincided with a renewal in the study of polysemy, which has taken place in the psycholinguistics camp mainly. There is already a fruitful interbreeding between two lines of research: the theoretical study of lexical word meaning, on the one hand, and the models of polysemy psycholinguists present, on the other. In this paper I aim at (...) deepening on this ongoing interbreeding, examine what is said about polysemy, particularly in the psycholinguistics literature, and then show how what we seem to know about the representation and storage of polysemous senses affects the models that we have about lexical word meaning. (shrink)

Internal relations are those relations that are intrinsic to the nature of one or more of the relata. They are a kind of essential relation, rather than an essential property. For example, an arc of a circle is internally related to the center of that circle in the sense that.

RésuméDans plusieurs articles importants et dans son récent livre, The Reliability of Sense Perception, William Alston a soutenu que la résistance traditionnelle à l'endroit de l'externalisme en théorie de la connaissance repose sur une crainte injustifiée de la circularité épistémique que l'externalisme entraîne. Nous maintenons, pour notre part, qu' Alston a tort d'absoudre la circularité épistémique de toute conséquence sceptique, et que sa défense de la circularité épistémique, par l'idée d'un «self-support significatif», échoue. Nous concluons, par conséquent, que l'internalisme traditionnel, (...) assorti d'une position ferme quant à la fiabilité des principes épistémiques, représente le seul espoir de réponse au scepticisme épistémique. (shrink)

The Russian philosopher and cultural theorist Mikhail Bakhtin has traditionally been seen as the leading figure in the group of intellectuals known as the Bakhtin Circle. The writings of other members of the Circle are considered much less important than his work, while Bakhtin's achievement has been exaggerated in proportion to the downgrading of the thinkers with whom he associated in the 1920s. This volume, which includes new translations and studies of the work of the most important members of the (...) Circle, sets out to correct the distortions in the established representations of its activity. The original contributions to literary and linguistic theory made by Valentin Voloshinov and Pavel Medvedev (but frequently credited to Bakhtin) are assessed, and the distinctiveness of their approaches is highlighted. (shrink)

Modeling law search and retrieval as prediction problems has recently emerged as a predominant approach in law intelligence. Focusing on the law article retrieval task, we present a deep learning framework named LamBERTa, which is designed for civil-law codes, and specifically trained on the Italian civil code. To our knowledge, this is the first study proposing an advanced approach to law article prediction for the Italian legal system based on a BERT (Bidirectional Encoder Representations from Transformers) learning framework, which has (...) recently attracted increased attention among deep learning approaches, showing outstanding effectiveness in several natural language processing and learning tasks. We define LamBERTa models by fine-tuning an Italian pre-trained BERT on the Italian civil code or its portions, for law article retrieval as a classification task. One key aspect of our LamBERTa framework is that we conceived it to address an extreme classification scenario, which is characterized by a high number of classes, the few-shot learning problem, and the lack of test query benchmarks for Italian legal prediction tasks. To solve such issues, we define different methods for the unsupervised labeling of the law articles, which can in principle be applied to any law article code system. We provide insights into the explainability and interpretability of our LamBERTa models, and we present an extensive experimental analysis over query sets of different type, for single-label as well as multi-label evaluation tasks. Empirical evidence has shown the effectiveness of LamBERTa, and also its superiority against widely used deep-learning text classifiers and a few-shot learner conceived for an attribute-aware prediction task. (shrink)

Implicit and explicit attitudes manifest themselves as distinct and partly dissociable behavioral dispositions. It is natural to think that these differences reflect differing underlying representations. The present article argues that this may be a mistake. Although non-verbal and verbal measures of attitudes often dissociate, this may be because the two types of outcome-measure are differentially impacted by other factors, not because they are tapping into distinct kinds of representation or distinct storage systems. I arrive at this view through (...) closer consideration than is usual of the mechanisms and processes that underlie overt behavior. (shrink)

Natural language processing techniques contribute more and more in analyzing legal documents recently, which supports the implementation of laws and rules using computers. Previous approaches in representing a legal sentence often based on logical patterns that illustrate the relations between concepts in the sentence, often consist of multiple words. Those representations cause the lack of semantic information at the word level. In our work, we aim to tackle such shortcomings by representing legal texts in the form of abstract meaning (...) class='Hi'>representation, a graph-based semantic representation that gains lots of polarity in NLP community recently. We present our study in AMR Parsing and AMR-to-text Generation specifically for legal domain. We also introduce JCivilCode, a human-annotated legal AMR dataset which was created and verified by a group of linguistic and legal experts. We conduct an empirical evaluation of various approaches in parsing and generating AMR on our own dataset and show the current challenges. Based on our observation, we propose our domain adaptation method applying in the training phase and decoding phase of a neural AMR-to-text generation model. Our method improves the quality of text generated from AMR graph compared to the baseline model. 2018; and “Legal Text Generation fromMeaning Representation”, published in the 32nd International Conference on Legal Knowledge and Information Systems 2019.). (shrink)

This paper surveys the impact on neuropsychology of Wittgenstein's elucidations of memory. Wittgenstein discredited the storage and imprint models of memory, dissolved the conceptual link between memory and mental images or representations and, upholding the context-sensitivity of memory, made room for a family resemblance concept of memory, where remembering can also amount to doing or saying something. While neuropsychology is still generally under the spell of archival and physiological notions of memory, Wittgenstein's reconceptions can be seen at work in (...) its leading-edge practitioners. However, neuroscientists, generally, are finding memory difficult to demarcate from other cognitive and noncognitive processes, and I suggest this is largely due to their considering automatic responses as part of memory, termed nondeclarative or implicit memory. Taking my lead from Wittgenstein's On Certainty, I argue that there is only remembering where there is also some kind of mnemonic effort or attention, and, therefore, that so-called implicit memory is not memory at all, but a basic, noncognitive certainty. (shrink)

Despite popular representations to the contrary, creative people are rarely insane. But creativity and madness may be connected in other ways; we find suggestions of schizotypy in the biographies of many artists, and schizophrenia and related conditions seem to be disproportionately represented in talented and creative families. There are attractions, therefore, in the idea that creativity depends on the controlled deployment of capacities that are uncontrolled in psychosis: an idea explored by psychoanalytically inclined writers such as Ernst Kris and Hanna (...) Segal. (shrink)

Most models of generational succession in sexually reproducing populations necessarily move back and forth between genic and genotypic spaces. We show that transitions between and within these spaces are usually hidden by unstated assumptions about processes in these spaces. We also examine a widely endorsed claim regarding the mathematical equivalence of kin-, group-, individual-, and allelic-selection models made by Lee Dugatkin and Kern Reeve. We show that the claimed mathematical equivalence of the models does not hold. *Received January 2007; revised (...) April 2008. †To contact the authors, please write to: Elisabeth Lloyd, Department of History and Philosophy of Science, 130 Goodbody Hall, Indiana University, Bloomington, IN 47405; e-mail: [email protected]; Richard Lewontin, Department of Organismic and Evolutionary Biology, Harvard University, 26 Oxford Street, Cambridge, MA 02138; Marcus Feldman, Department of Biological Sciences, Stanford University, Stanford, CA 94305; e-mail: [email protected]. (shrink)

The distinction between regular and irregular morphology is not clear-cut enough to suggest two distinct modular structures. Instead, regularity is tied directly to the type frequency of a pattern. Evidence from experiments as well as from naturally occurring sound change suggests that even regular forms have lexical storage. Finally, the development trajectory entailed by the dual-processing model is much more complex than that entailed by associative network models.

How did the events of the early modern period affect the way gender and the self were represented? This collection of essays attempts to respond to this question by analysing a wide spectrum of cultural concerns - humanism, technology, science, law, anatomy, literacy, domesticity, colonialism, erotic practices, and the theatre - in order to delineate the history of subjectivity and its relationship with the postmodern fragmented subject. The scope of this analysis expands the terrain explored by feminist theory, while its (...) feminist focus reveals that the subject is always gendered - although the terms in which gender is conceived and represented change across history. Feminist Readings of Early Modern Culture not only explores the representation of gendered subjects, but in its commitment to balancing the productive tensions of methodological diversity, also speaks to contemporary challenges facing feminism. (shrink)

Global environmental science, in its current configuration as predominantly interdisciplinary earth systems analysis, owes its existence to technological development in three respects. (1) Environmental impacts of globalization of corporate and military industrial development linked to widespread use of new technologies prompted investigation of ways to understand and anticipate the global nature of such impacts. (2) Extension of the reach of technology itself demands extension of attempts to anticipate and control the environment in which the technology is to function. Thus as (...) the reach becomes global, the environment in question is also global. (3) Such global studies cannot get far without the development of command, control and information technologies (computers, satellites, automated remote sensing devices) which are crucial for data gathering, storage, and analysis and for the simulation modeling, crucial to theory testing and prediction. This network of dependence on technological development gives the global environmental sciences a rather distinctive epistemological profile, one in which some distinctions that we had thought were clear, on the basis of models of classic laboratory sciences (such as those between experiment and deduction or representation and instrument), turn out to be far from clear. In consequence there needs to be a careful evaluation of the extent to which, or the ways in which, these sciences can provide bases for policy decisions. (shrink)

Frank Mitjans is an architect who has worked in London since 1976. He was introduced to the significance of the figure of St. Thomas More by Andrés Vázquez de Prada, author of the biography, Sir Tomás Moro, Lord Canciller de Inglaterra. In 1977 Vázquez de Prada invited Mitjans to visit with him the Thomas More Exhibition at the National Portrait Gallery, which stimulated his interest in representations of More, his family and his friends. Since August 2002 he has given many (...) presentations and talks on the topography of More’s London to groups of students and other interested people in Britain, Ireland, and Sweden. Frank Mitjans, architecte qui travaille à Londres depuis 1976, fut initié au personnage de Saint Thomas More par Andrés Vázquez de Prada, auteur de la biographie Sir Tomás Moro, Lord Canciller de Inglaterra. En 1977 Vázquez de Prada l’invita à l’accompagner dans sa visite de l’exposition Thomas More à la National Portrait Gallery, évènement qui aiguisa son intérêt pour les représentations de More, de sa famille et de ses amis. Depuis août 2002 il a régulièrement fait des présentations et des exposés à des groupes d’étudiants et d’autres en Grande-Bretagne, Irlande et Suède au sujet de la topographie du Londres de Thomas More. The recent exhibitions of the works of Holbein in London and Basel, and scholarly publications such as Holbein and England, have rekindled interest in the Portrait of Thomas More and his Family, and in the late sixteenth-century versions of Holbein’s presumed lost original. The present paper analyses the differences between the sixteenth-century versions and Holbein’s 1527 composition sketch, and concludes that the sketch is a more reliable witness to Holbein’s lost painting than the later versions, as well as the only authentic witness to More’s intentions; though anything we learn from the drawing must be checked against what we know from More’s letters and writings and other biographical data. From the later versions, however, and in particular from the references to Seneca on them, we can learn about those who commissioned them and England’s peculiar historical circumstances. (shrink)

The prevailing theoretical framework for theorising about representation construes all representation as involving objective representational contents. This classic framework has tended to drive philosophers either to claim that evaluative judgements are representations and therefore objective, or else to claim that evaluative judgements are not really representations, because they are not objective. However, a more general, already well-explored framework is available, which will allow theorists to treat evaluative judgements as full-fledged representations while leaving open whether they are objective. Such (...) a more general conception of representational content is exemplified, e.g. by Lewis's ‘centred contents’ and Gibbard's framework of ‘contents of judgement’, thus it is not new. I shall start in §1 by introducing the more general framework of perspectival contents and then illustrate in §2 how awareness of it can help expose the fallaciousness of certain widely used forms of argumentation in metaethics. (shrink)

Someday there will be no more articles written about the.

In attempting to integrate the authors' proposed model with results from analogous human event-related potential (ERP) research, we found difficulties with: (1) its apparent disregard for supraordinate representations at posterior multimodal association cortices, (2) its failure to address contextual task effects, and (3) its strict architectural dichotomy between memory storage and control functions.

The ontic conception of explanation is predicated on the proposition that “explanation is a relation between real objects in the world” and hence, according to this approach, scientific explanation cannot take place absent such a premise. Despite the fact that critics have emphasized several drawbacks of the ontic conception, as for example its inability to address the so-called “abstract explanations”, the debate is not settled and the ontic view can claim to capture cases of explanation that are non-abstract, such as (...) causal relations between events. However, by eliminating the distinction between abstract and non-abstract explanations, it follows that ontic and epistemic proposals can no longer contend to capture different cases of explanation and either all are captured by the ontic view or all are captured by the epistemic view. On closer inspection, it turns out that the ontic view deals with events that fall outside the scientists’ scope of observation and that it does not accommodate common instances of explanation such as explanations from false propositions and hence it cannot establish itself as the dominant philosophical stance with respect to explanation. On the contrary, the epistemic conception does account for almost all episodes of explanation and can be described as a relation between representations, whereby the explanans transmit information to the explanandum and that this information can come, dependent on context, in the form of any of the available theories of explanation (law-like, unificatory, causal and non-causal). The range of application of the ontic view thus is severely restricted to trivial cases of explanation that come through direct observation of the events involved in an explanation and explanation is to be mostly conceived epistemically. (shrink)

현상적 지향성 이론(phenomenal intentionality theory)은 주체(subject)의 현상적 상태를 통해 주체의 지향적 상태를 설명하는 이론이다. 현상적 지향성 이론의 한 가지 문제는 모든 지향적 상태가 고유한 현상적 상태를 동반하는 것은 아니라는 점이다. 멘델로비치(A. Mendelovici)는 이러한 문제를 해결하기 위해 이른바 ‘자기귀속주의(self-ascriptivism)’를 제안한다. 자기귀속주의에 따르면, 주체는 그가 가지는 현상적 상태가 무엇을 의미하는지 생각하는 성향을 가지고, 이러한 성향을 통해 다양한 지향적 상태들이 일어난다. 하지만 자기귀속주의는 주체의 지향적 상태를 그것에 관한 주체의 반성적인 생각을 통해 설명한다는 점에서 근본적으로 잘못되었다. 다른 한편 후설(E. Husserl)의 현상학에 근거하여 이러한 문제를 (...) 일으키지 않는 현상적 지향성 이론을 전개할 수 있다. 이러한 이론에 따르면, 주체가 가지는 현상적 상태는 주체가 아직 가지지 않는 이러저러한 현상적 상태들에 대한 기대를 일으키고, 이러한 기대를 통해 다양한 지향적 상태들이 일어난다. 그리고 이러한 기대는 이러저러한 현상적 상태들이 일어나면 만족하고 그렇지 않으면 실망하는 성향이다. 이러한 현상적 지향성 이론은 자기귀속주의에 있는 문제를 일으키지 않는다. 나아가 그것은 감각적이거나 감정적인 현상들로부터 구별되는 새로운 종류의 인식적 현상(cognitive phenomenology)을 필요로 하지 않는다. (shrink)

Hilary Putnam, who may have been the first philosopher to advance the notion that the computer is an apt model for the mind, takes a radically new view of his...

The concepts of representation and perception, which are specially employed and contextualised in this article, were introduced for cultural reflection by Arūnas Sverdiolas. Pamėklė is a Lithuanian equivalent of “simulacrum,” which can be associated with images that are distinguished by a doll effect and provoke spectator-participant reaction and involvement, and can therefore be associated with reckoned instruments of experience. Another strategy for representing a person encompasses the phenomenon of relics, the fragmentary remains of the body. The article shows how (...) these kinds of anthropomorphic representations of the body can be detected individually and how they can co-exist in a hybrid structure. The example of such a structure we can find in the exposition of relics from the body of St Boniface in the church in Valkininkai. (shrink)

The nub of the following argument is that there is a conflict between the idea of (liberal) neutrality on the one hand, and an intuitively plausible idea of political representation on the other. The conflict arises when neutrality is seen as a condition for political legitimacy: neutralist political representation is only legitimate insofar as the representative does not advance political ideas based on conceptions of the good that are not endorsed by the whole of the (reasonable) polity. However, (...) we often encounter examples of political representation that do not live up to this demand but nevertheless seem legitimate. Hence, neutralists should explain either why this counterintuitive notion of representation does not follow from neutrality or explain what representatives are meant and allowed to do in such a political arrangement. A plausible neutralist rejoinder to this is to say that legitimacy is not dependent on neutrality for all political decisions. Neutrality is important (only or predominantly) regarding a certain body of political decisions, viz., using the Rawlsian idiom, 'constitutional essentials and matters of basic justice.' However, such a two-levelled approach is not without its problems. I argue that a skein of theoretical and practical challenges to the two-levelled approach undermines, or at least weakens, this attempt to solve the problem about representation and neutrality, and that the two-levelled approach is unclear in certain key aspects. The aim of the article is, however, quite modest. It is not to challenge neutrality per se ; rather, it is a call for further clarification of the issues pertaining to the relationship between neutrality and representation. (shrink)

An early, very preliminary edition of this book was circulated in 1962 under the title Set-theoretical Structures in Science. There are many reasons for maintaining that such structures play a role in the philosophy of science. Perhaps the best is that they provide the right setting for investigating problems of representation and invariance in any systematic part of science, past or present. Examples are easy to cite. Sophisticated analysis of the nature of representation in perception is to be (...) found already in Plato and Aristotle. One of the great intellectual triumphs of the nineteenth century was the mechanical explanation of such familiar concepts as temperature and pressure by their representation in terms of the motion of particles. A more disturbing change of viewpoint was the realization at the beginning of the twentieth century that the separate invariant properties of space and time must be replaced by the space-time invariants of Einstein's special relativity. Another example, the focus of the longest chapter in this book, is controversy extending over several centuries on the proper representation of probability. The six major positions on this question are critically examined. Topics covered in other chapters include an unusually detailed treatment of theoretical and experimental work on visual space, the two senses of invariance represented by weak and strong reversibility of causal processes, and the representation of hidden variables in quantum mechanics. The final chapter concentrates on different kinds of representations of language, concluding with some empirical results on brain-wave representations of words and sentences. (shrink)

The papers collected in this volume exemplify some of the trends in current approaches to logic, language and computation. Written by authors with varied academic backgrounds, the contributions are intended for an interdisciplinary audience. The first part of this volume addresses issues relevant for multi-agent systems: reasoning with incomplete information, reasoning about knowledge and beliefs, and reasoning about games. Proofs as formal objects form the subject of Part II. Topics covered include: contributions on logical frameworks, linear logic, and different approaches (...) to formalized reasoning. Part III focuses on representations and formal methods in linguistic theory, addressing the areas of comparative and temporal expressions, modal subordination, and compositionality. (shrink)

In this article, network science is discussed from a methodological perspective, and two central theses are defended. The first is that network science exploits the very properties that make a system complex. Rather than using idealization techniques to strip those properties away, as is standard practice in other areas of science, network science brings them to the fore, and uses them to furnish new forms of explanation. The second thesis is that network representations are particularly helpful in explaining the properties (...) of non-decomposable systems. Where part-whole decomposition is not possible, network science provides a much-needed alternative method of compressing information about the behavior of complex systems, and does so without succumbing to problems associated with combinatorial explosion. The article concludes with a comparison between the uses of network representation analyzed in the main discussion, and an entirely distinct use of network representation that has recently been discussed in connection with mechanistic modeling. (shrink)

Short-term or working memory provides temporary storage of information in the brain after an experience and is associated with conscious awareness. Neurons sensitive to the multiple stimulus attributes comprising an experience are distributed within many brain regions. Such distributed cell assemblies, activated by an event, are the most plausible system to represent the WM of that event. Studies with a variety of imaging technologies have implicated widespread brain regions in the mediation of WM for different categories of information. Each (...) kind of WM may thus be expected to involve many brain regions rather than a local, uniquely dedicated set of cells. Neurons in a distributed “cell assembly” may be self-selected by their temporally coherent activations. The process by which this fragmented representation of the recent past is reassembled to accomplish essentially automatic and reliable recognition of a recurrent event constitutes an important problem. One plausible mechanism to achieve the identification of past with previous events would require that the representational system mediating WM must coexist in spatial extent and somehow overlap in temporal activation with cell ensembles registering input from subsequent events. The detection of such a postulated mechanism required an experimental approach which would focus upon spatial patterns of coherent activation while information about different events was stored in WM and retrieved, rather than focusing upon the temporal sequences of activation in localized regions of interest. For this purpose, the familiar delayed matching from sample task was modified. A series of information-free flashes, or “noncontingent probes,” was presented before an initial series of visual information items, the Priming Sample, which were to be held in WM during a Delay Period. A second series of visual information items were then presented, the Matching Sample. The task required detection of any item in the second series which had beenabsentfrom the initial series. Thirty such trials with a particular category of visual information constituted a single task. Several DMS tasks with this standardized design, but with different categories of visual information, were presented within each test session. The information categories included letters of the alphabet, single digit numbers, or faces from a school yearbook. Event-related potentials , were computed from 21 standardized electrode placements, separately for information-free probes and for information items in each interval of the trials within a task. Because each electrode is particularly sensitive to coherent activation of neurons in the immediately underlying brain regions, topographic maps were constructed and interpolated across the surface of the scalp. The momentary fluctuations of the resulting voltage “landscapes” throughout the task were then subjected to quantitative analysis. Distinctive landscapes sometimes persisted for prolonged periods, implying sustained engagement of very large populations of neurons. “Difference landscapes” were constructed by subtraction of topographic maps evoked by noncontingent probes during the Delay Period from maps of probe ERPs before the presentation of the initial information in the Priming Sample. Such probe difference landscapes displayed recurrent high similarity to momentary landscapes elicited during subsequent presentation of the information items in the Matching Sample. It seemed as if the distributed cell assembly continuously engaged by mediation of WM of the diverse attributes of the initial stimuli was being dynamically compared to the ensembles engaged by registration of the subsequent stimuli. Spatial Principal Component Analysis was applied to the sequences of momentary voltage landscapes observed throughout trials of each task. This method sought a small number of spatial patterns with which these large sets of inhomogeneous spatial distributions of voltage could be reconstructed. This is the spatial analog of the reconstruction of local ERPs by temporal principal components, as often described previously. Five Spatial Principal Components were found which accounted for about 90% of the total variance of voltage across the surface of the scalp throughout every task. Theloadings,or distinguishing topographic features, of these SPCs, were highly similar during every cognitive task for every subject. However,factor scores,or relative average contribution to the overall voltage distributions, of the different SPCs varied substantially among subjects between the tasks and momentarily within successive intervals of each task. These five SPCs may reflect coherent activation of huge distributed ensembles of neurons which comprise independent but interacting functional brain subsystems. These subsystems may correspond to basic resources available to individuals for allocation to mediate conscious evaluation of information during cognitive activity, providing a filter to bind together fractionated representations of the past to evaluate the present. (shrink)