A Landscape of Consciousness: Toward a Taxonomy of Explanations and Implications

Progress in Biophysics and Molecular Biology, Journal Year: 2024, Volume and Issue: 190, P. 28 - 169

Published: Jan. 26, 2024

Diverse explanations or theories of consciousness are arrayed on a roughly physicalist-to-nonphysicalist landscape essences and mechanisms. Categories: Materialism Theories (philosophical, neurobiological, electromagnetic field, computational informational, homeostatic affective, embodied enactive, relational, representational, language, phylogenetic evolution); Non-Reductive Physicalism; Quantum Theories; Integrated Information Theory; Panpsychisms; Monisms; Dualisms; Idealisms; Anomalous Altered States Challenge Theories. There many subcategories, especially for Each explanation is self-described by its adherents, critique minimal only clarification, there no attempt to adjudicate among theories. The implications assessed with respect four questions: meaning/purpose/value (if any); AI consciousness; virtual immortality; survival beyond death. A Landscape Consciousness, I suggest, offers perspective.

Language: Английский

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Duration of resuscitation, regain of consciousness and histopathological severity of hypoxic-ischemic encephalopathy after cardiac arrest

Resuscitation Plus, Journal Year: 2025, Volume and Issue: unknown, P. 100945 - 100945

Published: March 1, 2025

To study the histopathologically quantified severity of hypoxic-ischemic encephalopathy (HIE) in deceased cardiac arrest unbiased by death causes and correlated with demographic parameters. We conducted a retrospective, single-centre including patients postmortem brain autopsies. Using selective eosinophilic neuronal (SEND), histopathological HIE was cerebral neocortex, hippocampus, basal ganglia, cerebellum, brainstem, included 319 median time return from to spontaneous circulation (tROSC) 10 min, whom 62(19.4%) had regain consciousness (RoC) before death. The tROSC significantly SEND all regions (p < 0.05, Spearman's rho = 0.14 0.29). ganglia RoC -0.25 -0.11). In 9 tROSCs less than 1 brainstem 30%, 8(88.9%) neocortical 30%. Among 69 greater 20 47.8-82.6% showed 30% across regions. found more likely shorter tROSCs. A min mostly associated Prolonged resuscitations did not exclude relevant proportion patients. Future studies are warranted investigate impact modifiable clinical parameters on HIE.

Language: Английский

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Acute biomarkers of consciousness are associated with recovery after severe traumatic brain injury

medRxiv (Cold Spring Harbor Laboratory), Journal Year: 2025, Volume and Issue: unknown

Published: March 5, 2025

Abstract Objective Determine whether acute behavioral, electroencephalography (EEG), and functional MRI (fMRI) biomarkers of consciousness are associated with outcome after severe traumatic brain injury (TBI). Methods Patients TBI admitted consecutively to the intensive care unit (ICU) participated in a multimodal battery assessing behavioral level (Coma Recovery Scale-Revised [CRS-R]), cognitive motor dissociation (CMD; task-based EEG fMRI), covert cortical processing (CCP; stimulus-based default mode network connectivity (DMN; resting-state fMRI). The primary was 6-month Disability Rating Scale (DRS) total scores. Results We enrolled 55 patients TBI. Six-month available 45 (45.2±20.7 years old, 70% male), whom 10 died, all due withdrawal life-sustaining treatment (WLST). Behavioral presence command-following ICU were each lower (i.e., better) DRS scores (p=0.003, p=0.011). fMRI did not strengthen this relationship, but higher DMN better recovery on multiple secondary measures. In subsample participants without CRS-R, CMD (EEG:18%; fMRI:33%) CCP (EEG:91%; fMRI:79%) outcome, an unexpected result that may reflect high rate WLST. However, (ρ[95%CI]=-0.41[-0.707, -0.027]; p=0.046) group. Interpretation Standardized assessment improve prediction from Further research is required determine integrating EEG, more predictive than alone.

Language: Английский

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Shared subcortical arousal systems across sensory modalities during transient modulation of attention

NeuroImage, Journal Year: 2025, Volume and Issue: unknown, P. 121224 - 121224

Published: April 1, 2025

Language: Английский

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Restoring consciousness with pharmacologic therapy: Mechanisms, targets, and future directions

Neurotherapeutics, Journal Year: 2024, Volume and Issue: 21(4), P. e00374 - e00374

Published: July 1, 2024

Language: Английский

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Mesoscale Brain Mapping: Bridging Scales and Modalities in Neuroimaging – A Symposium Review

Neuroinformatics, Journal Year: 2024, Volume and Issue: 22(4), P. 679 - 706

Published: Sept. 23, 2024

Abstract Advances in the spatiotemporal resolution and field-of-view of neuroimaging tools are driving mesoscale studies for translational neuroscience. On October 10, 2023, Center Mesoscale Mapping (CMM) at Massachusetts General Hospital (MGH) Athinoula A. Martinos Biomedical Imaging Institute Technology (MIT) Health Sciences based Neuroimaging Training Program (NTP) hosted a symposium exploring state-of-the-art this rapidly growing area research. “Mesoscale Brain Mapping: Bridging Scales Modalities Neuroimaging” brought together researchers who use broad range imaging techniques to study brain structure function convergence microscopic macroscopic scales. The day-long event centered on areas which CMM has established expertise, including development emerging technologies their application clinical needs basic neuroscience questions. in-person welcomed more than 150 attendees, 57 faculty members, 61 postdoctoral fellows, 35 students, four industry professionals, represented institutions local, regional, international levels. also served training goals both NTP. content, organization, format were planned collaboratively by trainees. Many presented or participated panel discussion, thus contributing dissemination they have developed under auspices findings obtained using those technologies. NTP trainees benefited from included helped organize and/or posters gave “flash” oral presentations. In addition gaining experience presenting work, had opportunities throughout day engage one-on-one discussions with visiting scientists other faculty, potentially opening door future collaborations. presentations provided deep exploration many technological advances enabling progress structural functional imaging. Finally, students worked closely develop report summarizing content putting it broader context current state field share scientific community. We note that references cited here include conference abstracts corresponding poster

Language: Английский

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Subcortical Hubs of Brain Networks Sustaining Human Consciousness

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2024, Volume and Issue: unknown

Published: Oct. 5, 2024

Abstract Neuromodulation of subcortical network hubs by pharmacologic, electrical, or ultrasonic stimulation is a promising therapeutic strategy for patients with disorders consciousness (DoC). However, optimal targets are not well established. Here, we leveraged 7 Tesla resting-state functional MRI (rs-fMRI) data from 168 healthy subjects the Human Connectome Project to map connectivity six canonical cortical networks that modulate higher-order cognition and function: default mode, executive control, salience, dorsal attention, visual, somatomotor networks. Based on spatiotemporally overlapped generated Nadam-Accelerated SCAlable Robust (NASCAR) tensor decomposition method, our goal was identify functionally connected multiple We found ventral tegmental area (VTA) in midbrain central lateral (CL) parafascicular (Pf) nuclei thalamus – regions have historically been targeted neuromodulatory therapies restore widely Further, identified hub pontomesencephalic tegmentum reticular extrareticular arousal encompassed well-established “hot spot” coma-causing brainstem lesions. Multiple within thalamic intralaminar were both DMN SN, emphasizing importance these integrative subcortico-cortical signaling. Additional observed caudate head, putamen, amygdala, hippocampus, bed nucleus stria terminalis, classically associated modulation cognition, behavior, sensorimotor function. Collectively, results suggest tegmentum, thalamus, basal ganglia, medial temporal lobe function human brain. Our findings strengthen evidence targeting area, DoC. release all maps support ongoing efforts at neuromodulation consciousness.

Language: Английский

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Covert Consciousness in the ICU

Critical Care Medicine, Journal Year: 2024, Volume and Issue: 52(9), P. 1414 - 1426

Published: Aug. 15, 2024

OBJECTIVES: For critically ill patients with acute severe brain injuries, consciousness may reemerge before behavioral responsiveness. The phenomenon of covert (i.e., cognitive motor dissociation) be detected by advanced neurotechnologies such as task-based functional MRI (fMRI) and electroencephalography (EEG) in who appear unresponsive on the bedside examination. In this narrative review, we summarize state-of-the-science ICU detection consciousness. Further, consider prognostic therapeutic implications diagnosing ICU, well its potential to inform discussions about continuation life-sustaining therapy for injuries. DATA SOURCES: We reviewed salient medical literature regarding STUDY SELECTION: included clinical studies investigating diagnostic performance characteristics utility fMRI EEG. focus guidelines, professional society scientific statements, neuroethical analyses pertaining implementation detect EXTRACTION AND SYNTHESIS: extracted study results, guideline recommendations, statement recommendations diagnostic, prognostic, relevance care CONCLUSIONS: Emerging evidence indicates that is present approximately 15–20% Covert traumatic nontraumatic including whose examination suggests a comatose state. presence predict pace extent long-term recovery. Professional guidelines now recommend assessment using However, criteria patient selection investigations are uncertain global access limited.

Language: Английский

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Synthetic data in generalizable, learning-based neuroimaging

Imaging Neuroscience, Journal Year: 2024, Volume and Issue: 2, P. 1 - 22

Published: Jan. 1, 2024

Synthetic data have emerged as an attractive option for developing machine-learning methods in human neuroimaging, particularly magnetic resonance imaging (MRI)-a modality where image contrast depends enormously on acquisition hardware and parameters. This retrospective paper reviews a family of recently proposed methods, based synthetic data, generalizable machine learning brain MRI analysis. Central to this framework is the concept domain randomization, which involves training neural networks vastly diverse array synthetically generated images with random properties. technique has enabled robust, adaptable models that are capable handling contrasts, resolutions, pathologies, while working out-of-the-box, without retraining. We successfully applied method tasks such whole-brain segmentation (SynthSeg), skull-stripping (SynthStrip), registration (SynthMorph, EasyReg), super-resolution, MR transfer (SynthSR). Beyond these applications, discusses other possible use cases future work our methodology. Neural trained enable analysis clinical MRI, including large datasets, greatly alleviating (and sometimes eliminating) need substantial labeled offer enormous potential robust tools address various research goals.

Language: Английский

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Histology-guided MRI segmentation of brainstem nuclei critical to consciousness

medRxiv (Cold Spring Harbor Laboratory), Journal Year: 2024, Volume and Issue: unknown

Published: Sept. 28, 2024

Abstract While substantial progress has been made in mapping the connectivity of cortical networks responsible for conscious awareness, neuroimaging analysis subcortical arousal that modulate (i.e., wakefulness) limited by a lack robust segmentation procedures brainstem nuclei. Automated nuclei is an essential step toward elucidating physiology human consciousness and pathophysiology disorders consciousness. We created probabilistic atlas built on diffusion MRI scans five ex vivo brain specimens scanned at 750 μm isotropic resolution. Labels used to generate were manually annotated with reference nucleus-specific immunostaining two specimens. then developed Bayesian algorithm utilizes as generative model automatically identifies resolution- contrast-agnostic manner. The method displayed high accuracy both healthy lesioned T1 test-retest reliability across T2 contrasts. Finally, we show can detect volumetric changes differences magnetic susceptibility within Alzheimer’s disease traumatic coma, respectively. release tool advance study its disorders.

Language: Английский

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