scholarly journals Toward the unity of pathological and exertional fatigue: A predictive processing model

2021 ◽  
Author(s):  
A. Greenhouse-Tucknott ◽  
J. B. Butterworth ◽  
J. G. Wrightson ◽  
N. J. Smeeton ◽  
H. D. Critchley ◽  
...  
Keyword(s):  
Prediction Error ◽  
Conscious Experience ◽  
Physical Exertion ◽  
Generative Models ◽  
The Body ◽  
Predictive Processing ◽  
Research Fields ◽  
Common Foundation ◽  
Health And Disease ◽  
Sensory Evidence

AbstractFatigue is a common experience in both health and disease. Yet, pathological (i.e., prolonged or chronic) and transient (i.e., exertional) fatigue symptoms are traditionally considered distinct, compounding a separation between interested research fields within the study of fatigue. Within the clinical neurosciences, nascent frameworks position pathological fatigue as a product of inference derived through hierarchical predictive processing. The metacognitive theory of dyshomeostasis (Stephan et al., 2016) states that pathological fatigue emerges from the metacognitive mechanism in which the detection of persistent mismatches between prior interoceptive predictions and ascending sensory evidence (i.e., prediction error) signals low evidence for internal generative models, which undermine an agent’s feeling of mastery over the body and is thus experienced phenomenologically as fatigue. Although acute, transient subjective symptoms of exertional fatigue have also been associated with increasing interoceptive prediction error, the dynamic computations that underlie its development have not been clearly defined. Here, drawing on the metacognitive theory of dyshomeostasis, we extend this account to offer an explicit description of the development of fatigue during extended periods of (physical) exertion. Accordingly, it is proposed that a loss of certainty or confidence in control predictions in response to persistent detection of prediction error features as a common foundation for the conscious experience of both pathological and nonpathological fatigue.

scholarly journals Adjudicating Between Local and Global Architectures of Predictive Processing in the Subcortical Auditory Pathway

2021 ◽  
Vol 15 ◽  
Author(s):  
Alejandro Tabas ◽  
Katharina von Kriegstein
Keyword(s):  
Cerebral Cortex ◽  
Prediction Error ◽  
Sensory Input ◽  
Generative Models ◽  
Predictive Processing ◽  
Auditory Modality ◽  
Processing Stage ◽  
Information Encoding ◽  
Global View ◽  
Local View

Predictive processing, a leading theoretical framework for sensory processing, suggests that the brain constantly generates predictions on the sensory world and that perception emerges from the comparison between these predictions and the actual sensory input. This requires two distinct neural elements: generative units, which encode the model of the sensory world; and prediction error units, which compare these predictions against the sensory input. Although predictive processing is generally portrayed as a theory of cerebral cortex function, animal and human studies over the last decade have robustly shown the ubiquitous presence of prediction error responses in several nuclei of the auditory, somatosensory, and visual subcortical pathways. In the auditory modality, prediction error is typically elicited using so-called oddball paradigms, where sequences of repeated pure tones with the same pitch are at unpredictable intervals substituted by a tone of deviant frequency. Repeated sounds become predictable promptly and elicit decreasing prediction error; deviant tones break these predictions and elicit large prediction errors. The simplicity of the rules inducing predictability make oddball paradigms agnostic about the origin of the predictions. Here, we introduce two possible models of the organizational topology of the predictive processing auditory network: (1) the global view, that assumes that predictions on the sensory input are generated at high-order levels of the cerebral cortex and transmitted in a cascade of generative models to the subcortical sensory pathways; and (2) the local view, that assumes that independent local models, computed using local information, are used to perform predictions at each processing stage. In the global view information encoding is optimized globally but biases sensory representations along the entire brain according to the subjective views of the observer. The local view results in a diminished coding efficiency, but guarantees in return a robust encoding of the features of sensory input at each processing stage. Although most experimental results to-date are ambiguous in this respect, recent evidence favors the global model.

scholarly journals Being a beast machine: The origins of selfhood in control-oriented interoceptive inference

2018 ◽  
Author(s):  
Anil Seth
Keyword(s):  
Generative Models ◽  
The Body ◽  
Predictive Processing ◽  
Action Perception ◽  
Physiological Regulation ◽  
Sensory Signals ◽  
Andy Clark ◽  
Physiological Homeostasis ◽  
State Of Affairs ◽  
Embodied Selfhood

Throughout his career Andy Clark has shaped how scientists and philosophers think about the role of representation in action, perception, and cognition. In the latest iteration of this debate he has foregrounded the influential perspective of ‘predictive processing’, which sees perception as a process of action-oriented ‘best guessing’ (inference) about the causes of noisy and ambiguous sensory signals, and which involves the brain inducing ‘generative’ models of how hidden causes mediate the effects of actions on sensory signals. Here, I will develop this position in the context of interoception (the sense of the body from within) and physiological regulation. A key idea here, which recalls 20th century cybernetic theory, is that interoceptive inference is targeted towards maintaining physiological homeostasis rather than inducing complete and accurate internal models of an external state-of-affairs. I explore how this perspective helps connect control-oriented interoceptive inference to phenomenological properties of embodied selfhood and subjectivity. The upshot echoes (or perhaps subverts) a classic philosophical trope of the Enlightenment philosopher Julien La Mettrie: to find the origins of our conscious selves in our nature as beast machines.

scholarly journals The predictive brain in action: Involuntary actions reduce body prediction errors

2020 ◽  
Author(s):  
Pablo Lanillos ◽  
Sae Franklin ◽  
David W. Franklin
Keyword(s):  
Prediction Error ◽  
Sensory Information ◽  
The Body ◽  
Predictive Processing ◽  
Body Ownership ◽  
Prediction Errors ◽  
Uncertain Information ◽  
Energy Principle ◽  
Virtual Hand ◽  
The Brain

AbstractThe perception of our body in space is flexible and manipulable. The predictive brain hypothesis explains this malleability as a consequence of the interplay between incoming sensory information and our body expectations. However, given the interaction between perception and action, we might also expect that actions would arise due to prediction errors, especially in conflicting situations. Here we describe a computational model, based on the free-energy principle, that forecasts involuntary movements in sensorimotor conflicts. We experimentally confirm those predictions in humans by means of a virtual reality rubber-hand illusion. Participants generated movements (forces) towards the virtual hand, regardless of its location with respect to the real arm, with little to no forces produced when the virtual hand overlaid their physical hand. The congruency of our model predictions and human observations shows that the brain-body is generating actions to reduce the prediction error between the expected arm location and the new visual arm. This observed unconscious mechanism is an empirical validation of the perception-action duality in body adaptation to uncertain situations and evidence of the active component of predictive processing.Author SummaryHumans’ capacity to perceive and control their body in space is central in awareness, adaptation and safe interaction. From low-level body perception to body-ownership, discovering how the brain represents the body and generates actions is of major importance for cognitive science and also for robotics and artificial intelligence. The present study shows that humans move their body to match the expected location according to other (visual) sensory input, which corresponds to reducing the prediction error. This means that the brain adapts to conflicting or uncertain information from the senses by unconsciously acting in the world.

scholarly journals A Predictive Processing Account of Bottom-Up Visual Saliency Using Cross-Predicting Autoencoders

2018 ◽  
Author(s):  
Beren Millidge ◽  
Richard Shillcock
Keyword(s):  
Prediction Error ◽  
Visual Saliency ◽  
Generative Models ◽  
Predictive Processing ◽  
Bottom Up ◽  
Low Level ◽  
Sense Data ◽  
Saliency Maps ◽  
Human Participants ◽  
The Brain

We propose a novel predictive processing account of bottom-up visual saliency in which salience is simply the low-level prediction error between the sense-data and the predictions produced by the generative models in the brain. We test this with modelling in which we use cross-predicting deep autoencoders to create salience maps in an entirely unsupervised way. The resulting maps closely mimic experimentally derived human saliency maps and also spontaneously learn a centre bias, a robust viewing behaviour seen in human participants.

scholarly journals Predictive Processing and Body Representation

2021 ◽  
Author(s):  
Stephen Gadsby ◽  
Jakob Hohwy
Keyword(s):  
Prediction Error ◽  
General Scheme ◽  
Body Representation ◽  
The Body ◽  
Predictive Processing ◽  
Domain Specific ◽  
Term Prediction ◽  
Long Term Prediction

We introduce the predictive processing account of body representation, according to which body representation emerges via a domain-general scheme of (long-term) prediction error minimisation. We contrast this account against one where body representation is underpinned by domain-specific systems, whose exclusive function is to track the body. We illustrate how the predictive processing account offers considerable advantages in explaining various empirical findings, and we draw out some implications for body representation research.

Being a Beast Machine

2019 ◽  
pp. 238-253 ◽  
Author(s):  
Anil K. Seth
Keyword(s):  
Generative Models ◽  
The Body ◽  
Predictive Processing ◽  
Action Perception ◽  
Physiological Regulation ◽  
Sensory Signals ◽  
Andy Clark ◽  
Physiological Homeostasis ◽  
State Of Affairs ◽  
Embodied Selfhood

Throughout his career Andy Clark has shaped how scientists and philosophers think about the role of representation in action, perception, and cognition. In the latest iteration of this debate he has foregrounded the influential perspective of predictive processing, which sees perception as a process of action-oriented “best guessing” (inference) about the causes of noisy and ambiguous sensory signals and which involves the brain-inducing “generative” models of how hidden causes mediate the effects of actions on sensory signals. This chapter develops this position in the context of interoception (the sense of the body from within) and physiological regulation. A key idea here, which recalls twentieth-century cybernetic theory, is that interoceptive inference is targeted towards maintaining physiological homeostasis rather than inducing complete and accurate internal models of an external state of affairs. The chapter explores how this perspective helps connect control-oriented interoceptive inference to phenomenological properties of embodied selfhood and subjectivity. The upshot echoes (or perhaps subverts) a classic philosophical trope of the Enlightenment philosopher Julien de La Mettrie: to find the origins of our conscious selves in our nature as beast machines.

scholarly journals Toward an Embodied, Embedded Predictive Processing Account

2021 ◽  
Vol 12 ◽  
Author(s):  
Elmarie Venter
Keyword(s):  
Free Energy ◽  
Prediction Error ◽  
The Body ◽  
The Other ◽  
Predictive Processing ◽  
Error Minimization ◽  
Energy Principle ◽  
Free Energy Principle ◽  
Prediction Error Minimization

In this paper, I argue for an embodied, embedded approach to predictive processing and thus align the framework with situated cognition. The recent popularity of theories conceiving of the brain as a predictive organ has given rise to two broad camps in the literature that I call free energy enactivism and cognitivist predictive processing. The two approaches vary in scope and methodology. The scope of cognitivist predictive processing is narrow and restricts cognition to brain processes and structures; it does not consider the body-beyond-brain and the environment as constituents of cognitive processes. Free energy enactivism, on the other hand, includes all self-organizing systems that minimize free energy (including non-living systems) and thus does not offer any unique explanations for more complex cognitive phenomena that are unique to human cognition. Furthermore, because of its strong commitment to the mind-life continuity thesis, it does not provide an explanation of what distinguishes more sophisticated cognitive systems from simple systems. The account that I develop in this paper rejects both of these radical extremes. Instead, I propose a compromise that highlights the necessary components of predictive processing by making use of a mechanistic methodology of explanation. The starting point of the argument in this paper is that despite the interchangeable use of the terms, prediction error minimization and the free energy principle are not identical. But this distinction does not need to disrupt the status quo of the literature if we consider an alternative approach: Embodied, Embedded Predictive Processing (EEPP). EEPP accommodates the free energy principle, as argued for by free energy enactivism, but it also allows for mental representations in its explanation of cognition. Furthermore, EEPP explains how prediction error minimization is realized but, unlike cognitivist PP, it allocates a constitutive role to the body in cognition. Despite highlighting concerns regarding cognitivist PP, I do not wish to discredit the role of the neural domain or representations as free energy enactivism does. Neural structures and processes undeniably contribute to the minimization of prediction error but the role of the body is equally important. On my account, prediction error minimization and free energy minimization are deeply dependent on the body of an agent, such that the body-beyond-brain plays a constitutive role in cognitive processing. I suggest that the body plays three constitutive roles in prediction error minimization: The body regulates cognitive activity, ensuring that cognition and action are intricately linked. The body acts as distributor in the sense that it carries some of the cognitive load by fulfilling the function of minimizing prediction error. Finally, the body serves to constrain the information that is processed by an agent. In fulfilling these three roles, the agent and environment enter into a bidirectional relation through influencing and modeling the structure of the other. This connects EEPP to the free energy principle because the whole embodied agent minimizes free energy in virtue of being a model of its econiche. This grants the body a constitutive role as part of the collection of mechanisms that minimize prediction error and free energy. The body can only fulfill its role when embedded in an environment, of which it is a model. In this sense, EEPP offers the most promising alternative to cognitivist predictive processing and free energy enactivism.

The antitoxic and protective effects of Curcuma longa and it`s active agent, Curcumin: оverview

2020 ◽  
pp. 66-72
Author(s):  
A. Khisamova ◽  
O. Gizinger
Keyword(s):  
Curcuma Longa ◽  
Physiological Activity ◽  
Active Agent ◽  
Modern Science ◽  
Physical Exertion ◽  
The Body ◽  
Modern World ◽  
Protective Effects ◽  
Daily Stress ◽  
Anti Cancer

In the modern world, where a person is exposed to daily stress, increased physical exertion, the toxic effect of various substances, including drugs. The task of modern science is to find antioxidants for the body. These can be additives obtained both synthetically and the active substances that we get daily from food. Such a striking example is turmeric, obtained from the plant Curcuma longa. Recently, it has been known that curcumin has an antioxidant, anti-inflammatory, anti-cancer effect and, thanks to these effects, plays an important role in the prevention and treatment of various diseases, in particular, from cancer to autoimmune, neurological, cardiovascular and diabetic diseases. In addition, much attention is paid to increasing the biological activity and physiological effects of curcumin on the body through the synthesis of curcumin analogues. This review discusses the chemical and physical characteristics, analogues, metabolites, the mechanisms of its physiological activity and the effect of curcumin on the body.

scholarly journals Effects of Inbreeding on Genetic Characteristic, Growth, Survival Rates, and Immune Responses of a New Inbred Line of Exopalaemon carinicauda

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Jiajia Wang ◽  
Jitao Li ◽  
Qianqian Ge ◽  
Zhao Chen ◽  
Jian Li
Keyword(s):  
Immune Responses ◽  
Inbred Line ◽  
Survival Rates ◽  
The Body ◽  
Exopalaemon Carinicauda ◽  
Economic Traits ◽  
Gene Frequencies ◽  
Research Fields ◽  
Ssr Loci ◽  
Genetic Detection

The Exopalaemon carinicauda could be a useful crustacean laboratory animal in many research fields. We newly established an inbred line of Exopalaemon carinicauda named EC4 inbred line by brother×sister mating and keeping to F11 generation. Trends in heterozygosity in the process of producing EC4 inbred line were examined through the characterization of polymorphisms based on gene frequencies of SNP and EST-SSR loci. The results demonstrated that the number of alleles (N), observed heterozygosity (Ho), expected heterozygosity (He), and polymorphism information content (PIC) gradually decreased with the increase of inbreeding generations. The genetic detection results indicated that 9 (29.03%, 9/31) of the SNP loci and 15 (32.61%, 15/46) of the EST-SSR loci were homozygous in F11 generation of EC4 inbred line. The variation of the growth-related traits, the immune responses, and antioxidant status were described in experimental full-sibling inbred populations of E. carinicauda at five levels of inbreeding coefficient (F=0.785, F=0.816, F=0.859, F=0.886, F=0.908) under controlled laboratory conditions. The body weight, body length, and survival rate in EC4 inbred line of all generations were less than the control population. Inbreeding affected the antibacterial activity, phenoloxidase (PO) activity, and superoxide dismutase (SOD) which decreased at the eleventh generation of EC4 inbred line. This study demonstrated that inbreeding had a negative effect on the economic traits and immune response, but our inbred line was established successfully until F11 and confirmed by genetic detection using SNP and EST-SSR loci.

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