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https://www.readbyqxmd.com/read/29780343/-seeing-the-dark-grounding-phenomenal-transparency-and-opacity-in-precision-estimation-for-active-inference
#1
Jakub Limanowski, Karl Friston
One of the central claims of the Self-model Theory of Subjectivity is that the experience of being someone - even in a minimal form - arises through a transparent phenomenal self-model, which itself can in principle be reduced to brain processes. Here, we consider whether it is possible to distinguish between phenomenally transparent and opaque states in terms of active inference. We propose a relationship of phenomenal opacity to expected uncertainty or precision; i.e., the capacity for introspective attention and implicit mental action...
2018: Frontiers in Psychology
https://www.readbyqxmd.com/read/29758234/a-validation-of-dynamic-causal-modelling-for-7t-fmri
#2
S Tak, J Noh, C Cheong, P Zeidman, A Razi, W D Penny, K J Friston
BACKGROUND: There is growing interest in ultra-high field magnetic resonance imaging (MRI) in cognitive and clinical neuroscience studies. However, the benefits offered by higher field strength have not been evaluated in terms of effective connectivity and dynamic causal modelling (DCM). NEW METHOD: In this study, we address the validity of DCM for 7T functional MRI data at two levels. First, we evaluate the predictive validity of DCM estimates based upon 3T and 7T in terms of reproducibility...
May 11, 2018: Journal of Neuroscience Methods
https://www.readbyqxmd.com/read/29747865/deep-temporal-models-and-active-inference
#3
Karl J Friston, Richard Rosch, Thomas Parr, Cathy Price, Howard Bowman
How do we navigate a deeply structured world? Why are you reading this sentence first - and did you actually look at the fifth word? This review offers some answers by appealing to active inference based on deep temporal models. It builds on previous formulations of active inference to simulate behavioural and electrophysiological responses under hierarchical generative models of state transitions. Inverting these models corresponds to sequential inference, such that the state at any hierarchical level entails a sequence of transitions in the level below...
May 7, 2018: Neuroscience and Biobehavioral Reviews
https://www.readbyqxmd.com/read/29740369/am-i-self-conscious-or-does-self-organization-entail-self-consciousness
#4
Karl Friston
Is self-consciousness necessary for consciousness? The answer is yes. So there you have it-the answer is yes. This was my response to a question I was asked to address in a recent AEON piece (https://aeon.co/essays/consciousness-is-not-a-thing-but-a-process-of-inference). What follows is based upon the notes for that essay, with a special focus on self-organization, self-evidencing and self-modeling. I will try to substantiate my (polemic) answer from the perspective of a physicist. In brief, the argument goes as follows: if we want to talk about creatures, like ourselves, then we have to identify the characteristic behaviors they must exhibit...
2018: Frontiers in Psychology
https://www.readbyqxmd.com/read/29718139/ion-channels-in-eeg-isolating-channel-dysfunction-in-nmda-receptor-antibody-encephalitis
#5
Mkael Symmonds, Catherine H Moran, M Isabel Leite, Camilla Buckley, Sarosh R Irani, Klaas Enno Stephan, Karl J Friston, Rosalyn J Moran
Neurological and psychiatric practice frequently lack diagnostic probes that can assess mechanisms of neuronal communication non-invasively in humans. In N-methyl-d-aspartate (NMDA) receptor antibody encephalitis, functional molecular assays are particularly important given the presence of NMDA antibodies in healthy populations, the multifarious symptomology and the lack of radiological signs. Recent advances in biophysical modelling techniques suggest that inferring cellular-level properties of neural circuits from macroscopic measures of brain activity is possible...
April 30, 2018: Brain: a Journal of Neurology
https://www.readbyqxmd.com/read/29694845/interoceptive-inference-from-computational-neuroscience-to-clinic
#6
REVIEW
Andrew P Owens, Micah Allen, Sasha Ondobaka, Karl J Friston
The central and autonomic nervous systems can be defined by their anatomical, functional and neurochemical characteristics, but neither functions in isolation. For example, fundamental components of autonomically mediated homeostatic processes are afferent interoceptive signals reporting the internal state of the body and efferent signals acting on interoceptive feedback assimilated by the brain. Recent predictive coding (interoceptive inference) models formulate interoception in terms of embodied predictive processes that support emotion and selfhood...
April 22, 2018: Neuroscience and Biobehavioral Reviews
https://www.readbyqxmd.com/read/29643221/a-variational-approach-to-niche-construction
#7
REVIEW
Axel Constant, Maxwell J D Ramstead, Samuel P L Veissière, John O Campbell, Karl J Friston
In evolutionary biology, niche construction is sometimes described as a genuine evolutionary process whereby organisms, through their activities and regulatory mechanisms, modify their environment such as to steer their own evolutionary trajectory, and that of other species. There is ongoing debate, however, on the extent to which niche construction ought to be considered a bona fide evolutionary force, on a par with natural selection. Recent formulations of the variational free-energy principle as applied to the life sciences describe the properties of living systems, and their selection in evolution, in terms of variational inference...
April 2018: Journal of the Royal Society, Interface
https://www.readbyqxmd.com/read/29621266/intrinsic-and-extrinsic-motivators-of-attachment-under-active-inference
#8
David Cittern, Tobias Nolte, Karl Friston, Abbas Edalat
This paper addresses the formation of infant attachment types within the context of active inference: a holistic account of action, perception and learning in the brain. We show how the organised forms of attachment (secure, avoidant and ambivalent) might arise in (Bayesian) infants. Specifically, we show that these distinct forms of attachment emerge from a minimisation of free energy-over interoceptive states relating to internal stress levels-when seeking proximity to caregivers who have a varying impact on these interoceptive states...
2018: PloS One
https://www.readbyqxmd.com/read/29572721/planning-and-navigation-as-active-inference
#9
Raphael Kaplan, Karl J Friston
This paper introduces an active inference formulation of planning and navigation. It illustrates how the exploitation-exploration dilemma is dissolved by acting to minimise uncertainty (i.e. expected surprise or free energy). We use simulations of a maze problem to illustrate how agents can solve quite complicated problems using context sensitive prior preferences to form subgoals. Our focus is on how epistemic behaviour-driven by novelty and the imperative to reduce uncertainty about the world-contextualises pragmatic or goal-directed behaviour...
March 23, 2018: Biological Cybernetics
https://www.readbyqxmd.com/read/29560899/precision-psychiatry
#10
Karl J Friston
No abstract text is available yet for this article.
November 2017: Biological Psychiatry: Cognitive Neuroscience and Neuroimaging
https://www.readbyqxmd.com/read/29528294/clinical-applications-of-stochastic-dynamic-models-of-the-brain-part-ii-a-review
#11
REVIEW
James A Roberts, Karl J Friston, Michael Breakspear
Brain activity derives from intrinsic dynamics (due to neurophysiology and anatomical connectivity) in concert with stochastic effects that arise from sensory fluctuations, brainstem discharges, and random microscopic states such as thermal noise. The dynamic evolution of systems composed of both dynamic and random fluctuations can be studied with stochastic dynamic models (SDMs). This article, Part II of a two-part series, reviews applications of SDMs to large-scale neural systems in health and disease. Stochastic models have already elucidated a number of pathophysiological phenomena, such as epilepsy and hypoxic ischemic encephalopathy, although their use in biological psychiatry remains rather nascent...
April 2017: Biological Psychiatry: Cognitive Neuroscience and Neuroimaging
https://www.readbyqxmd.com/read/29528293/clinical-applications-of-stochastic-dynamic-models-of-the-brain-part-i-a-primer
#12
REVIEW
James A Roberts, Karl J Friston, Michael Breakspear
Biological phenomena arise through interactions between an organism's intrinsic dynamics and stochastic forces-random fluctuations due to external inputs, thermal energy, or other exogenous influences. Dynamic processes in the brain derive from neurophysiology and anatomical connectivity; stochastic effects arise through sensory fluctuations, brainstem discharges, and random microscopic states such as thermal noise. The dynamic evolution of systems composed of both dynamic and random effects can be studied with stochastic dynamic models (SDMs)...
April 2017: Biological Psychiatry: Cognitive Neuroscience and Neuroimaging
https://www.readbyqxmd.com/read/29527157/computational-neuropsychology-and-bayesian-inference
#13
REVIEW
Thomas Parr, Geraint Rees, Karl J Friston
Computational theories of brain function have become very influential in neuroscience. They have facilitated the growth of formal approaches to disease, particularly in psychiatric research. In this paper, we provide a narrative review of the body of computational research addressing neuropsychological syndromes, and focus on those that employ Bayesian frameworks. Bayesian approaches to understanding brain function formulate perception and action as inferential processes. These inferences combine 'prior' beliefs with a generative (predictive) model to explain the causes of sensations...
2018: Frontiers in Human Neuroscience
https://www.readbyqxmd.com/read/29514946/progressive-neurodegeneration-following-spinal-cord-injury-implications-for-clinical-trials
#14
Gabriel Ziegler, Patrick Grabher, Alan Thompson, Daniel Altmann, Markus Hupp, John Ashburner, Karl Friston, Nikolaus Weiskopf, Armin Curt, Patrick Freund
OBJECTIVE: To quantify atrophy, demyelination, and iron accumulation over 2 years following acute spinal cord injury and to identify MRI predictors of clinical outcomes and determine their suitability as surrogate markers of therapeutic intervention. METHODS: We assessed 156 quantitative MRI datasets from 15 patients with spinal cord injury and 18 controls at baseline and 2, 6, 12, and 24 months after injury. Clinical recovery (including neuropathic pain) was assessed at each time point...
April 3, 2018: Neurology
https://www.readbyqxmd.com/read/29478431/what-is-mood-a-computational-perspective
#15
James E Clark, Stuart Watson, Karl J Friston
The neurobiological understanding of mood, and by extension mood disorders, remains elusive despite decades of research implicating several neuromodulator systems. This review considers a new approach based on existing theories of functional brain organisation. The free energy principle (a.k.a. active inference), and its instantiation in the Bayesian brain, offers a complete and simple formulation of mood. It has been proposed that emotions reflect the precision of - or certainty about - the predicted sensorimotor/interoceptive consequences of action...
February 26, 2018: Psychological Medicine
https://www.readbyqxmd.com/read/29475638/hierarchical-active-inference-a-theory-of-motivated-control
#16
REVIEW
Giovanni Pezzulo, Francesco Rigoli, Karl J Friston
Motivated control refers to the coordination of behaviour to achieve affectively valenced outcomes or goals. The study of motivated control traditionally assumes a distinction between control and motivational processes, which map to distinct (dorsolateral versus ventromedial) brain systems. However, the respective roles and interactions between these processes remain controversial. We offer a novel perspective that casts control and motivational processes as complementary aspects - goal propagation and prioritization, respectively - of active inference and hierarchical goal processing under deep generative models...
April 2018: Trends in Cognitive Sciences
https://www.readbyqxmd.com/read/29407941/active-inference-and-the-anatomy-of-oculomotion
#17
Thomas Parr, Karl J Friston
Given that eye movement control can be framed as an inferential process, how are the requisite forces generated to produce anticipated or desired fixation? Starting from a generative model based on simple Newtonian equations of motion, we derive a variational solution to this problem and illustrate the plausibility of its implementation in the oculomotor brainstem. We show, through simulation, that the Bayesian filtering equations that implement 'planning as inference' can generate both saccadic and smooth pursuit eye movements...
March 2018: Neuropsychologia
https://www.readbyqxmd.com/read/29343629/the-markov-blankets-of-life-autonomy-active-inference-and-the-free-energy-principle
#18
REVIEW
Michael Kirchhoff, Thomas Parr, Ensor Palacios, Karl Friston, Julian Kiverstein
This work addresses the autonomous organization of biological systems. It does so by considering the boundaries of biological systems, from individual cells to Home sapiens, in terms of the presence of Markov blankets under the active inference scheme-a corollary of the free energy principle. A Markov blanket defines the boundaries of a system in a statistical sense. Here we consider how a collective of Markov blankets can self-assemble into a global system that itself has a Markov blanket; thereby providing an illustration of how autonomous systems can be understood as having layers of nested and self-sustaining boundaries...
January 2018: Journal of the Royal Society, Interface
https://www.readbyqxmd.com/read/29331491/investigating-the-relationship-between-cardiac-interoception-and-autonomic-cardiac-control-using-a-predictive-coding-framework
#19
Andrew P Owens, Karl J Friston, David A Low, Christopher J Mathias, Hugo D Critchley
Predictive coding models, such as the 'free-energy principle' (FEP), have recently been discussed in relation to how interoceptive (afferent visceral feedback) signals update predictions about the state of the body, thereby driving autonomic mediation of homeostasis. This study appealed to 'interoceptive inference', under the FEP, to seek new insights into autonomic (dys)function and brain-body integration by examining the relationship between cardiac interoception and autonomic cardiac control in healthy controls and patients with forms of orthostatic intolerance (OI); to (i) seek empirical support for interoceptive inference and (ii) delineate if this relationship was sensitive to increased interoceptive prediction error in OI patients during head-up tilt (HUT)/symptom provocation...
March 2018: Autonomic Neuroscience: Basic & Clinical
https://www.readbyqxmd.com/read/29331218/knowing-when-to-stop-aberrant-precision-and-evidence-accumulation-in-schizophrenia
#20
Roberto Limongi, Bartosz Bohaterewicz, Magdalena Nowicka, Aleksandra Plewka, Karl J Friston
Predictive coding and active inference formulations of the dysconnection hypothesis suggest that subjects with schizophrenia (SZ) hold unduly precise prior beliefs to compensate for a failure of sensory attenuation. This implies that SZ subjects should both initiate responses prematurely during evidence-accumulation tasks and fail to inhibit their responses at long stop-signal delays. SZ and healthy control subjects were asked to report the timing of billiards-ball collisions and were occasionally required to withhold their responses...
January 10, 2018: Schizophrenia Research
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