Search Results

This chapter considers two ways of employing a spatial resolution that varies with position within a finite-difference method: using a nonuniform grid and mapping to a new coordinate variable. It first provides an overview of nonuniform grids before discussing coordinate mapping as an alternative way of achieving spatial discretization. It then describes an approach for treating both the vertical and horizontal directions with simple finite-difference methods: defining a streamfunction, which automatically satisfies mass conservation, and solving for vorticity via the curl of the momentum conservation equation. It also explains the use of the Chebyshev–Fourier method to simulate the convection or gravity wave problem by employing spectral methods in both the horizontal and vertical directions. Finally, it looks at the basic ideas and some issues that need to be addressed with respect to parallel processing as well as choices that need to be made when designing a parallel code.

This chapter first briefly reviews the basic circuitry that underlies parallel processing. It then considers the anatomical basis for integration across different corticobasal ganglia circuits (with a particular emphasis on dopamine), and functional support for integrative processes. While the focus is on primate studies, key rodent experiments are also highlighted when primate data are unavailable.

Organizations are living complex systems and as such are vulnerable to the impact of trauma and adversity. This chapter explores how groups respond to stress and suggests that as a result of acute and chronic organizational stress, destructive processes occur within and between organizations that mirror or “parallel” the processes for which clients seek help. The result for them is “sanctuary trauma”, while the result for providers of service is a collective maladjustments as the organizations within which we work cease fulfilling a fundamental social role, that of containing anxiety in the face of death, suffering, defeat, and uncertainty. In such cases, social defense mechanisms come to dominate whatever therapeutic activity is supposed to be occurring in the social service environment. However, these parallel processes can be named and understood within the context of present knowledge of individual and group psychology.

This chapter discusses the neural correlates of human action perception, specifically the perception of bodies and body movements. It also provides a brief discussion on the likely connection of this network to additional cortical areas associated with more abstract properties of action perception, such as perceived intentionality. An introduction to the primary perceptual pathways in the visual cortex for generalized motion and form perception is presented, as well as some preliminary evidence for specialized circuits dedicated to biological motion perception.

This chapter examines the assumption that literal meanings are functionally primary: are they, as opposed to figurative meanings, processed automatically, and are they processed more quickly? Experimental evidence is adduced to show that, like literally intended expressions, metaphors and idioms are processed automatically, i.e., in an obligatory fashion. Furthermore, metaphors are processed in parallel with literal language when both kinds of meanings are available. Even the time-course of interpretation is the same for literal and metaphorical expressions. The primacy of the literal can be clearly rejected.

This chapter discusses prevailing biological and cognitive accounts of how the mind creates meaning. It starts with the notion that the mind is the work of a biological brain, provides a brief review of the structure and function of the brain, and goes on to explore cognitive models of mind, including associative network and parallel distributive processing models of organized memories (or schemas), and declarative and procedural forms of knowledge. The chapter discusses points of convergence among these conceptions, their contributions to the C-I perspective, and their practical utility in informing practice. In particular, emphasis is given to processes involved in helping clients transform declarative or descriptive knowledge into procedural or how-to knowledge.

The question of whether visual search involves at least one item-by-item serial processing stage or whether instead it is an entirely parallel process has been debated for decades. Recently, estimates of ‘attentional dwell-time’, which is the time required to reallocate attention from one item to another, have been brought to bear on this question. This chapter reviews this and other classes of evidence that favor serial or parallel models of visual search, and concludes that hybrid models that are neither strictly serial nor strictly parallel are better candidates for describing human visual search. The chapter ends with a sketch of one such model, and some of its possibilities.

This chapter reviews the features of the visual and oculomotor systems that are particularly important for understanding active vision. First, the chapter describes the inhomogeneity of the visual projections and the consequences of the resulting inhomogeneity on visual abilities. Human vision has a high resolution fovea at the centre and visual ability falling off quickly into peripheral vision. Second, the evidence for multiple types of parallel processing within the visual and oculomotor system is reviewed. Third, the basic characteristics of the oculomotor system are described and different types of eye movement are identified, followed by a more detailed description of saccadic eye movements: the fast ballistic eye movements that move the fovea to point at regions of interest.

This chapter presents an autobiography of Nobuo Suga. Suga and his collaborators explored the neural mechanisms for parallel and hierarchical processing of biosonar information and the cortical maps representing different types of biosonar information. They also explored the role of the corticofugal (descending) auditory system in the improvement and adjustment of auditory signal processing and the neural circuit for plastic changes in the central auditory system elicited by auditory fear conditioning. His early years, career, and achievements are discussed.

Research for which the idea that many basic cognitive processes can be described as fast, parallel, and automatic is reviewed. Memory retrieval/decision processes have often been ignored in the cognitive literature. However, in some cases, computationally complex processes can be replaced with simple passive processes. Cue-dependent retrieval from memory provides a straightforward example of how encoding, memory, and retrieval can interact. Three other examples are reviewed: inference in text processing, compound cue models for priming, and implicit memory. In each case, the research benefits from a focus on retrieval and decision processes. For implicit memory, consideration of these kinds of processes leads to a view of implicit memory different than hypothesizing new specialized memory systems. Finally, how behavioral data from simple decisions and the models that explain the behavior can be related to neuroscience research on neural firing rates are discussed.

This concluding chapter represents an ending and a beginning–the conclusion of this volume and an introduction to what will be more fully covered in a forthcoming volume - a parallel process of recovery for organizations that we call The Sanctuary Model. The Sanctuary Model offers an evidence-supported trauma-informed theory and methodology for changing organizational cultures. We will only touch on the main components of the model here and explore the subject in more depth in the third volume of this trilogy. We briefly introduce the central concepts of the Sanctuary Model as a change in the operating system for organizations. After briefing describing the Seven Sanctuary Commitments we discuss how the Sanctuary Model is being implemented via the Sanctuary Institute, the Sanctuary Network and Sanctuary Certification.

The most characteristic field pattern of the waking, activated neocortex is gamma oscillation. Its generation depends on the time decay of GABA_A-receptor-mediated Laurent inhibition and/or shunting. These receptors are uniformly distributed in the cerebral cortex and other brain regions. Because inhibitory postsynaptic potentials mediated by these neurons are reliable, they provide a more efficient means for timing than excitatory postsynaptic potentials. Due to the localized axon arbors of basket and chandelier cells and the local gap junctions, gamma oscillations in the cortex are often confined to a small piece of tissue. Coupling of distant gamma oscillators requires fast-conducting conduits, provided by the widespread axon collaterals of long-range interneurons and possibly by the long axons of some pyramidal cells. The physiological importance of the gamma rhythm is supported by the observation that neuronal assemblies in the waking brain self-organize themselves into temporal packages of 15 to 30 milliseconds.

Outlines a theory of genres: of what they are, what they do, and what they explain. The central notion is that of a genre‐for‐a‐community, which depends on psychological facts concerning tendencies of expectation in the audience. The minimal conditions for a genre to be instantiated are weak; Outlines some stronger conditions which allow us to focus on self‐conscious genre‐based effects. Suggests that genre, even thus strengthened, has only a very weak explanatory role. Gives accounts of genre identity across time, and of genre change.

This chapter examines how “moved by the past” can be a form of regression, with particular emphasis on how we may act out a necrophylic relationship with a past that is more dead than we suspect—and in which we consequently reproduce a past that is more alive than we think. Focusing on the Netherlands Institute for War Documentation (NIOD) report about the alleged inability of Dutch peacekeepers to protect the Bosnian Muslims herded together in the “safe area” of Srebrenica in 1995, the chapter describes how a parallel process is going on when difficulties experienced in one environment are replicated in another environment. It considers the case of the NIOD historians to show that it is completely at odds with how we like to conceive the relation between historians and what they write about. The chapter suggests that studying historical works by means of parallel process theory transcends the introversion of both postmodernist theory of history and the positivist practice of history.

This chapter offers a scientific theory of the nature of human memory that fits naturally with the view of memory as a constructive process. This theory, the complementary learning systems theory, is grounded in a broad framework for understanding human cognitive processes called the parallel distributed processing (PDP) framework, a framework the author of this chapter helped develop with David Rumelhart and others in 1986. At the time the theory was presented in 1995, the focus was on one of the theory's two complementary learning systems, a fast-learning system in the medial temporal lobes of the brain. Subsequent work with Timothy Rogers, presented in Semantic Cognition, focused on the other, slow-learning system, located elsewhere in the neocortex. Later sections lay out the theory itself and distinguish it from other researchers' approaches to the neuroscience of memory. It then considers recent developments, as well as questions about the theory and its relevance to the humanities.

This introductory chapter sets out the book’s purpose, which is to develop a neurologically plausible theory of grammatic function. It then discusses parallel distributed processing (PDP), one of the major pillars of the book. PDP models can incorporate a large variety of model-specific assumptions, including ones that are not neurologically plausible. However, the book argues from the simplest, most limited set of assumptions possible, all of which receive substantial if not overwhelming support from neurobiological research. These assumptions are outlined.

This chapter extends the model presented in this book to incorporate a basis for grammatic function, and summarizes the broader model in quasi-mathematical terms in order to show, in compact form, how the pieces fit together. This dense formulation serves as the anchor point for the discussions that follow, which unpack the equations. The model to be developed, despite the quasi-mathematical formulations and the absolutely crucial parallel distributed processing grounding, will be theoretical and conceptual.