scholarly journals Sub-Optimal Learning of Tactile-Spatial Predictions in Patients with Complex Regional Pain Syndrome

2019 ◽  
Author(s):  
Christopher A. Brown ◽  
Ingrid Scholtes ◽  
Nicholas Shenker ◽  
Michael C. Lee
Keyword(s):  
Complex Regional Pain Syndrome ◽  
Statistical Learning ◽  
Bayesian Model ◽  
Pain Syndrome ◽  
Higher Order ◽  
Spatial Displacement ◽  
Top Down ◽  
Bottom Up ◽  
Spatial Changes ◽  
Statistical Regularities

ABSTRACTIn Complex Regional Pain Syndrome (CRPS), tactile sensory deficits have motivated the therapeutic use of sensory discrimination training. However, the hierarchical organisation of the brain is such that low-level sensory processing can be dynamically influenced by higher-level knowledge, e.g. knowledge learnt from statistical regularities in the environment. It is unknown whether the learning of such statistical regularities is impaired in CRPS. Here, we employed a hierarchical Bayesian model of predictive coding to investigate statistical learning of tactile-spatial predictions in CRPS. Using a sensory change-detection task, we manipulated bottom-up (spatial displacement of a tactile stimulus) and top-down (probabilistic structure of occurrence) factors to estimate hierarchies of prediction and prediction error signals, as well as their respective precisions or reliability. Behavioural responses to spatial changes were influenced by both the magnitude of spatial displacement (bottom-up) and learnt probabilities of change (top-down). The Bayesian model revealed that patients’ predictions (of spatial displacements) were found to be less precise, deviating further from the ideal (statistical optimality) compared to healthy controls. This imprecision was less context-dependent, i.e. more enduring across changes in probabilistic context and less finely-tuned to statistics of the environment. This caused greater precision on prediction errors, resulting in predictions that were driven more by momentary spatial changes and less by the history of spatial changes. These results suggest inefficiencies in higher-order statistical learning in CRPS. This may have implications for therapies based on sensory re-training whose effects may be more short-lived if success depends on higher-order learning.

A Hierarchical Bayesian Model for Learning Nonlinear Statistical Regularities in Nonstationary Natural Signals

2005 ◽  
Vol 17 (2) ◽  
pp. 397-423 ◽  
Author(s):  
Yan Karklin ◽  
Michael S. Lewicki
Keyword(s):  
Latent Variables ◽  
Bayesian Model ◽  
Principal Component ◽  
Component Analysis ◽  
Higher Order ◽  
Hierarchical Bayesian ◽  
Hierarchical Bayesian Model ◽  
Complex Signals ◽  
Scaling Properties ◽  
Statistical Regularities

Capturing statistical regularities in complex, high-dimensional data is an important problem in machine learning and signal processing. Models such as principal component analysis (PCA) and independent component analysis (ICA) make few assumptions about the structure in the data and have good scaling properties, but they are limited to representing linear statistical regularities and assume that the distribution of the data is stationary. For many natural, complex signals, the latent variables often exhibit residual dependencies as well as nonstationary statistics. Here we present a hierarchical Bayesian model that is able to capture higher-order nonlinear structure and represent nonstationary data distributions. The model is a generalization of ICA in which the basis function coefficients are no longer assumed to be independent; instead, the dependencies in their magnitudes are captured by a set of density components. Each density component describes a common pattern of deviation from the marginal density of the pattern ensemble; in different combinations, they can describe nonstationary distributions. Adapting the model to image or audio data yields a nonlinear, distributed code for higher-order statistical regularities that reflect more abstract, invariant properties of the signal.

The Origin of Consciousness

2010 ◽  
Vol 18 (3) ◽  
pp. 481-495
Author(s):  
Jonathan Cole
Keyword(s):  
Clinical Medicine ◽  
Neural Correlates ◽  
Higher Order ◽  
Brain Anatomy ◽  
Special Issue ◽  
Top Down ◽  
Bottom Up ◽  
Neural Correlates Of Consciousness ◽  
Definition Of ◽  
External Stimuli

This paper introduces the background to the debate addressed by the papers of this Special Issue of Pragmatics & Cognition. Starting with a definition of consciousness it traces some ways in which the term is applied; from clinical medicine, where it relates somewhat crudely to responsiveness to external stimuli, to more cognitive and philosophical aspects such as higher order consciousness and its content. It then discusses the relation of consciousness to brain anatomy, the neural correlates of consciousness, and its possible evolution. In the meeting which forms the basis for Frith’s core paper, Christof Koch also made important contributions, here précised. A discussion of the origins of consciousness in relation to the top-down and bottom-up models brought to the fore follows suit.

scholarly journals Bottom-Up and Top-Down Paradigms for Psychopathology: A Half-Century Odyssey

2020 ◽  
Vol 16 (1) ◽  
pp. 1-24 ◽  
Author(s):  
Thomas M. Achenbach
Keyword(s):  
Empirical Data ◽  
Higher Order ◽  
Assessment Instruments ◽  
Assessment Data ◽  
Top Down ◽  
Services Research ◽  
Bottom Up ◽  
Conceptual Representations ◽  
And Training ◽  
Internalizing And Externalizing

Bottom-up paradigms prioritize empirical data from which to derive conceptualizations of psychopathology. These paradigms use multivariate statistics to identify syndromes of problems that tend to co-occur plus higher-order groupings such as those designated as internalizing and externalizing. Bottom-up assessment instruments obtain self-ratings and collateral ratings of behavioral, emotional, social, and thought problems and strengths for ages 1½–90+. Ratings of population samples provide norms for syndrome and higher-order scales for each gender, at different ages, rated by different informants, in relation to multicultural norms. The normed assessment instruments operationalize the empirically derived syndromes and higher-order groupings for applications to clinical services, research, and training. Because cross-informant agreement is modest and no single informant provides comprehensive assessment data, software compares ratings by different informants. Top-down paradigms prioritize conceptual representations of the nature and structure of psychopathology, as exemplified by psychodynamic, DSM/ICD, and HiTOP paradigms. Although these paradigms originated with observations, they tend to prioritize conceptual representations over empirical data.

scholarly journals Biology by Design: From Top to Bottom and Back

2010 ◽  
Vol 2010 ◽  
pp. 1-11 ◽  
Author(s):  
Brian R. Fritz ◽  
Laura E. Timmerman ◽  
Nichole M. Daringer ◽  
Joshua N. Leonard ◽  
Michael C. Jewett
Keyword(s):  
Synthetic Biology ◽  
Conceptual Model ◽  
Biological Systems ◽  
Higher Order ◽  
Trial And Error ◽  
Top Down ◽  
Bottom Up ◽  
Societal Needs ◽  
Technical Discipline ◽  
Higher Order Networks

Synthetic biology is a nascent technical discipline that seeks to enable the design and construction of novel biological systems to meet pressing societal needs. However, engineering biology still requires much trial and error because we lack effective approaches for connecting basic “parts” into higher-order networks that behave as predicted. Developing strategies for improving the performance and sophistication of our designs is informed by two overarching perspectives: “bottom-up” and “top-down” considerations. Using this framework, we describe a conceptual model for developing novel biological systems that function and interact with existing biological components in a predictable fashion. We discuss this model in the context of three topical areas: biochemical transformations, cellular devices and therapeutics, and approaches that expand the chemistry of life. Ten years after the construction of synthetic biology's first devices, the drive to look beyond what does exist to what can exist is ushering in an era of biology by design.

Integrating Interventions after Traumatic Brain Injury: A Synergistic Approach to Neurorehabilitation

2013 ◽  
Vol 14 (1) ◽  
pp. 51-62 ◽  
Author(s):  
Kristen Dams-O'Connor ◽  
Wayne A. Gordon
Keyword(s):  
Emotional Regulation ◽  
Day Treatment ◽  
Life Quality ◽  
Executive Dysfunction ◽  
Higher Order ◽  
Integrative Approach ◽  
Top Down ◽  
Bottom Up ◽  
Psychotherapeutic Interventions ◽  
Synergistic Approach

Deficits in attention, processing speed and executive functioning are among the most commonly reported and functionally limiting cognitive impairments among individuals with TBI. Changes in mood can exacerbate cognitive deficits and reduce life quality. Contemporary hierarchical models of cognitive functioning suggest that attention/arousal processes underlie and support higher-order functions. Building on decades of clinical research, a synergistic, integrative approach to neurorehabilitation is described, which combines bottom-up and top-town cognitive interventions in addition to psychotherapeutic interventions for mood. This approach is intended to address directly impairments in both foundational (i.e., attention) and higher-order (i.e., executive functions) processes. Executive dysfunction is addressed in a top-down fashion through the application of a series of problem-solving and emotional regulation modules that teach and integrate strategies that can be generalised across situations with practice. Attention, arousal and information processing are necessary prerequisites of successful higher-order thinking, attention skills, and are addressed in a bottom-up fashion through intensive individualised attention and processing training tasks. Combining top-down and bottom-up approaches within a comprehensive day-treatment programme can effect a synergistic improvement of overall functioning.

scholarly journals Expectation in Melody: The Influence of Context and Learning

2006 ◽  
Vol 23 (5) ◽  
pp. 377-405 ◽  
Author(s):  
Marcus T. Pearce ◽  
Geraint A. Wiggins
Keyword(s):  
Experimental Data ◽  
Factor Model ◽  
Empirical Support ◽  
Cognitive Systems ◽  
Musical Experience ◽  
Ir Theory ◽  
Top Down ◽  
Bottom Up ◽  
Statistical Regularities ◽  
Better Than

The Implication-Realization (IR) theory (Narmour, 1990) posits two cognitive systems involved in the generation of melodic expectations: The first consists of a limited number of symbolic rules that are held to be innate and universal; the second reflects the top-down influences of acquired stylistic knowledge. Aspects of both systems have been implemented as quantitative models in research which has yielded empirical support for both components of the theory (Cuddy & Lunny, 1995; Krumhansl, 1995a, 1995b; Schellenberg, 1996, 1997). However, there is also evidence that the implemented bottom-up rules constitute too inflexible a model to account for the influence of the musical experience of the listener and the melodic context in which expectations are elicited. A theory is presented, according to which both bottom-up and top-down descriptions of observed patterns of melodic expectation may be accounted for in terms of the induction of statistical regularities in existing musical repertoires. A computational model that embodies this theory is developed and used to reanalyze existing experimental data on melodic expectancy. The results of three experiments with increasingly complex melodic stimuli demonstrate that this model is capable of accounting for listeners’ expectations as well as or better than the two-factor model of Schellenberg (1997).

Top-down, bottom-up and selection-history-based control of attention: A failed trichotomy? The case of Priming of pop-out (PoP)

2020 ◽  
Author(s):  
Aniruddha Ramgir ◽  
Dominique Lamy
Keyword(s):  
Empirical Evidence ◽  
Statistical Learning ◽  
Past Experience ◽  
Present Review ◽  
Top Down ◽  
Bottom Up ◽  
Attentional Guidance ◽  
Selection History

When we search for an object, our performance is strongly influenced by our past experience. In the lab, this influence has been demonstrated by investigating a variety of phenomena, including inter-trial priming, statistical learning and reward history, and collectively referred to as selection history. The resulting findings have led researchers to claim that selection history guides attention, thereby challenging the prevailing dichotomy, according to which attentional priority is determined solely by top-down goals and bottom-up salience. The objective of the present review is to reexamine this claim by evaluating the evidence that specifically pertains to the role of selection history in attentional guidance, rather than in later processes occurring after the target is found. We focus on one selection history phenomenon, priming of pop-out (PoP). After demarcating the conditions under which PoP effects can be dissociated from top-down effects, we review the relevant findings, while distinguishing between the main experimental rationales adopted to address this question. We conclude that despite some inconsistencies that should be resolved by further research, most of the extant empirical evidence does not support the idea that PoP affects attentional priority. We call for similar reevaluations of other selection history phenomena and caution against burying the bottom-up vs. top-down dichotomy too hastily.

scholarly journals Neuronal Activity in the Rat Pulvinar Correlates with Multiple Higher-Order Cognitive Functions

Vision ◽  
2020 ◽  
Vol 4 (1) ◽  
pp. 15
Author(s):  
Fang-Chi Yang ◽  
Rebecca D. Burwell
Keyword(s):  
Neuronal Activity ◽  
Cognitive Functions ◽  
Target Location ◽  
Stimulus Onset ◽  
Visuospatial Attention ◽  
Higher Order ◽  
Top Down ◽  
Bottom Up ◽  
Thalamic Input ◽  
Selection Behavior

The pulvinar, also called the lateral posterior nucleus of the thalamus in rodents, is one of the higher-order thalamic relays and the main visual extrageniculate thalamic nucleus in rodents and primates. Although primate studies report the pulvinar is engaged under attentional demands, there are open questions about the detailed role of the pulvinar in visuospatial attention. The pulvinar provides the primary thalamic input to the posterior parietal cortex (PPC). Both the pulvinar and the PPC are known to be important for visuospatial attention. Our previous work showed that neuronal activity in the PPC correlated with multiple phases of a visuospatial attention (VSA) task, including onset of the visual stimuli, decision-making, task-relevant locations, and behavioral outcomes. Here, we hypothesized that the pulvinar, as the major thalamic input to the PPC, is involved in visuospatial attention as well as in other cognitive functions related to the processing of visual information. We recorded the neuronal activity of the pulvinar in rats during their performance on the VSA task. The task was designed to engage goal-directed, top–down attention as well as stimulus-driven, bottom–up attention. Rats monitored three possible locations for the brief appearance of a target stimulus. An approach to the correct target location was followed by a liquid reward. For analysis, each trial was divided into behavioral epochs demarcated by stimulus onset, selection behavior, and approach to reward. We found that neurons in the pulvinar signaled stimulus onset and selection behavior consistent with the interpretation that the pulvinar is engaged in both bottom–up and top–down visuospatial attention. Our results also suggested that pulvinar cells responded to allocentric and egocentric task-relevant locations.

A Historical Review of Complex Regional Pain Syndrome in the “Guides Library”

2009 ◽  
Vol 14 (6) ◽  
pp. 1-9
Author(s):  
Robert J. Barth
Keyword(s):  
Differential Diagnosis ◽  
Complex Regional Pain Syndrome ◽  
Reflex Sympathetic Dystrophy ◽  
International Association ◽  
Historical Review ◽  
Pain Syndrome ◽  
Sixth Edition

Abstract Complex regional pain syndrome (CRPS) is a controversial, ambiguous, unreliable, and unvalidated concept that, for these very reasons, has been justifiably ignored in the “AMA Guides Library” that includes the AMAGuides to the Evaluation of Permanent Impairment (AMA Guides), the AMA Guides Newsletter, and other publications in this suite. But because of the surge of CRPS-related medicolegal claims and the mission of the AMA Guides to assist those who adjudicate such claims, a discussion of CRPS is warranted, especially because of what some believe to be confusing recommendations regarding causation. In 1994, the International Association for the Study of Pain (IASP) introduced a newly invented concept, CRPS, to replace the concepts of reflex sympathetic dystrophy (replaced by CRPS I) and causalgia (replaced by CRPS II). An article in the November/December 1997 issue of The Guides Newsletter introduced CRPS and presciently recommended that evaluators avoid the IASP protocol in favor of extensive differential diagnosis based on objective findings. A series of articles in The Guides Newsletter in 2006 extensively discussed the shortcomings of CRPS. The AMA Guides, Sixth Edition, notes that the inherent lack of injury-relatedness for the nonvalidated concept of CRPS creates a dilemma for impairment evaluators. Focusing on impairment evaluation and not on injury-relatedness would greatly simplify use of the AMA Guides.

Peripheral Nerve and Brachial Plexus Impairment, AMA Guides, Sixth Edition

2017 ◽  
Vol 22 (2) ◽  
pp. 3-5
Author(s):  
James B. Talmage ◽  
Jay Blaisdell
Keyword(s):  
Peripheral Nerve ◽  
Brachial Plexus ◽  
Complex Regional Pain Syndrome ◽  
Lower Extremities ◽  
Pain Syndrome ◽  
Upper Extremities ◽  
Motor Deficits ◽  
Type I ◽  
Sixth Edition ◽  
Nerve Entrapments

Abstract Physicians use a variety of methodologies within the AMA Guides to the Evaluation of Permanent Impairment (AMA Guides), Sixth Edition, to rate nerve injuries depending on the type of injury and location of the nerve. Traumatic injuries that cause impairment to the peripheral or brachial plexus nerves are rated using Section 15.4e, Peripheral Nerve and Brachial Plexus Impairment, for upper extremities and Section 16.4c, Peripheral Nerve Rating Process, for lower extremities. Verifiable nerve lesions that incite the symptoms of complex regional pain syndrome, type II (similar to the former concept of causalgia), also are rated in these sections. Nerve entrapments, which are not isolated traumatic events, are rated using the methodology in Section 15.4f, Entrapment Neuropathy. Type I complex regional pain syndrome is rated using Section 15.5, Complex Regional Pain Syndrome for upper extremities or Section 16.5, Complex Regional Pain Syndrome for lower extremities. The method for grading the sensory and motor deficits is analogous to the method described in previous editions of AMA Guides. Rating the permanent impairment of the peripheral nerves or brachial plexus is similar to the methodology used in the diagnosis-based impairment scheme with the exceptions that the physical examination grade modifier is never used to adjust the default rating and the names of individual nerves or plexus trunks, as opposed to the names of diagnoses, appear in the far left column of the rating grids.

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