The Hard Problem of Consciousness and the Free Energy Principle
This article applies the free energy principle to the hard problem of consciousness. After clarifying some philosophical issues concerning functionalism, it identifies the elemental form of consciousness as affect and locates its physiological mechanism (an extended form of homeostasis) in the upper brainstem. This mechanism is then formalized in terms of free energy minimization (in unpredicted contexts) where decreases and increases in expected uncertainty are felt as pleasure and unpleasure, respectively. Emphasis is placed on the reasons why such existential imperatives feel like something to and for an organism.
PyDecNef: An open-source framework for fMRI-based decoded neurofeedback
https://www.biorxiv.org/content/10.1101/2023.10.02.560503v1
As I walked alongside science, I made a profound discovery: that every life has its limits. That's why meeting all of you like this feels like a miracle, and now, living feels so dear and precious.
There may be times of conflict and setbacks. However, I just want to send my sincere feelings to you.
The Salience Network: A Neural System for Perceiving and Responding to Homeostatic Demands
https://www.jneurosci.org/content/39/50/9878
The Salience Network: A Neural System for Perceiving and Responding to Homeostatic Demands
The term “salience network” refers to a suite of brain regions whose cortical hubs are the anterior cingulate and ventral anterior insular (i.e., frontoinsular) cortices. This network, which also includes nodes in the amygdala, hypothalamus, ventral striatum, thalamus, and specific brainstem nuclei, coactivates in response to diverse experimental tasks and conditions, suggesting a domain-general function. In the 12 years since its initial description, the salience network has been extensively studied, using diverse methods, concepts, and mammalian species, including healthy and diseased humans across the lifespan. Despite this large and growing body of research, the essential functions of the salience network remain uncertain. In this paper, which makes no attempt to comprehensively review this literature, I describe the circumstances surrounding the initial discovery, conceptualization, and naming of the salience network, highlighting aspects that may be unfamiliar to many readers. I then discuss some of the key advances provided by subsequent research and conclude by posing a few of the questions that remain to be explored.
Neuropsychology Review
Embodying Time in the Brain: A Multi-Dimensional Neuroimaging Meta-Analysis of 95 Duration Processing Studies
https://link.springer.com/article/10.1007/s11065-023-09588-1
Embodying Time in the Brain: A Multi-Dimensional Neuroimaging Meta-Analysis of 95 Duration Processing Studies - Neuropsychology Review
Time is an omnipresent aspect of almost everything we experience internally or in the external world. The experience of time occurs through such an extensive set of contextual factors that, after decades of research, a unified understanding of its neural substrates is still elusive. In this study, following the recent best-practice guidelines, we conducted a coordinate-based meta-analysis of 95 carefully-selected neuroimaging papers of duration processing. We categorized the included papers into 14 classes of temporal features according to six categorical dimensions. Then, using the activation likelihood estimation (ALE) technique we investigated the convergent activation patterns of each class with a cluster-level family-wise error correction at p < 0.05. The regions most consistently activated across the various timing contexts were the pre-SMA and bilateral insula, consistent with an embodied theory of timing in which abstract representations of duration are rooted in sensorimotor and interoceptive experience, respectively. Moreover, class-specific patterns of activation could be roughly divided according to whether participants were timing auditory sequential stimuli, which additionally activated the dorsal striatum and SMA-proper, or visual single interval stimuli, which additionally activated the right middle frontal and inferior parietal cortices. We conclude that temporal cognition is so entangled with our everyday experience that timing stereotypically common combinations of stimulus characteristics reactivates the sensorimotor systems with which they were first experienced.
Nature Neuroscience
Interoceptive rhythms in the brain
https://www.nature.com/articles/s41593-023-01425-1
Interoceptive rhythms in the brain - Nature Neuroscience
Engelen et al. review in animals and humans how the CNS senses cardiac, respiratory and gastric rhythmic activity, and detail the range of cognitive functions impacted, from perceptual detection up to the sense of self.
The Integrated Information Theory of Consciousness as Pseudoscience
https://psyarxiv.com/zsr78/
