Unravelling consciousness and brain function through the lens of time, space, and information

Trends in Neurosciences, Journal Year: 2024, Volume and Issue: 47(7), P. 551 - 568

Published: May 31, 2024

Disentangling how cognitive functions emerge from the interplay of brain dynamics and network architecture is among major challenges that neuroscientists face. Pharmacological pathological perturbations consciousness provide a lens to investigate these complex challenges. Here, we review recent advances about brain's functional organisation have been driven by common denominator: decomposing function into fundamental constituents time, space, information. Whereas unconsciousness increases structure-function coupling across scales, psychedelics may decouple structure. Convergent effects also emerge: anaesthetics, psychedelics, disorders can exhibit similar reconfigurations unimodal-transmodal axis. Decomposition approaches reveal potential translate discoveries species, with computational modelling providing path towards mechanistic integration.

Language: Английский

---

A Synergistic Workspace for Human Consciousness Revealed by Integrated Information Decomposition

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2020, Volume and Issue: unknown

Published: Nov. 26, 2020

Abstract A central goal of neuroscience is to understand how the brain orchestrates information from multiple input streams into a unified conscious experience. Here, we address two fundamental questions: human information-processing architecture functionally organised, and does its organisation support consciousness? We combine network science rigorous information-theoretic notion synergy delineate “synergistic global workspace”, comprising gateway regions that gather synergistic specialised modules across brain. This then integrated within workspace widely distributed via broadcaster regions. Through functional MRI analysis, show correspond brain’s default mode network, whereas broadcasters coincide with executive control network. Demonstrating empirical relevance our proposed for neural processing, loss consciousness due general anaesthesia or disorders corresponds diminished ability integrate information, which restored upon recovery. Thus, coincides breakdown integration work contributes conceptual reconciliation between prominent scientific theories consciousness, Global Neuronal Workspace Integrated Information Theory. Taken together, this provides new perspective on role resting-state networks architecture, while also advancing understanding supports through information.

Language: Английский

---

Decreased Thalamic Activity Is a Correlate for Disconnectedness during Anesthesia with Propofol, Dexmedetomidine and Sevoflurane But Not S-Ketamine

Journal of Neuroscience, Journal Year: 2023, Volume and Issue: 43(26), P. 4884 - 4895

Published: May 24, 2023

Establishing the neural mechanisms responsible for altered global states of consciousness during anesthesia and dissociating these from other drug-related effects remains a challenge in research. We investigated differences brain activity between connectedness disconnectedness by administering various anesthetics at concentrations designed to render 50% subjects unresponsive. One hundred sixty healthy male were randomized receive either propofol (1.7 μg/ml; n = 40), dexmedetomidine (1.5 ng/ml; sevoflurane (0.9% end-tidal; S-ketamine (0.75 20), or saline placebo ( 20) 60 min using target-controlled infusions vaporizer with end-tidal monitoring. Disconnectedness was defined as unresponsiveness verbal commands probed 2.5-min intervals unawareness external events postanesthesia interview. High-resolution positron emission tomography (PET) used quantify regional cerebral metabolic rates glucose (CMR glu ) utilization. Contrasting scans where classified connected responsive versus disconnected unresponsive revealed that all anesthetics, except S-ketamine, level thalamic differed states. A conjunction analysis across propofol, groups confirmed thalamus primary structure reduced related disconnectedness. Widespread cortical suppression observed when subjects, disconnected, compared group, suggesting findings may represent necessary but alone insufficient change state consciousness. SIGNIFICANCE STATEMENT Experimental is commonly search measures function which could distinguish However, most previous studies have not been separate drug exposure. employed novel study design disentangle exposing predefined EC 50 doses four placebo. demonstrate state-related are remarkably limited widespread In particular, decreased associated S-ketamine.

Language: Английский

---

Cerebral electrometabolic coupling in disordered and normal states of consciousness

Cell Reports, Journal Year: 2023, Volume and Issue: 42(8), P. 112854 - 112854

Published: July 27, 2023

We assess cerebral integrity with cortical and subcortical FDG-PET electroencephalography (EEG) within the mesocircuit model framework in patients disorders of consciousness (DoCs). The hypothesis proposes that activation facilitates function. find metabolic balance areas is informative for diagnosis associated four EEG-based power spectral density patterns, metabolism, α healthy controls a DoC. Last, regional electrometabolic coupling at level can be identified θ ranges, showing positive negative relations glucose uptake, respectively. This relation inverted DoC, potentially related to altered orchestration neural activity, may underlie suboptimal excitability states By understanding neurobiological basis pathophysiology underlying DoCs, we foresee translational value treatment

Language: Английский

---

Brain Activity Characteristics of Patients With Disorders of Consciousness in the EEG Resting State Paradigm: A Review

Frontiers in Systems Neuroscience, Journal Year: 2022, Volume and Issue: 16

Published: May 27, 2022

The assessment of the level consciousness in disorders (DoC) is still one most challenging problems contemporary medicine. Nevertheless, based on multitude studies conducted over last 20 years resting states electroencephalography (EEG) DoC, it possible to outline brain activity profiles related both patients without preserved and minimally conscious ones. In case consciousness, dominance low, mostly delta, frequency, marginalization higher frequencies were observed, terms global power functional connectivity patterns. turn, revealed opposite pattern—the characteristics frequency bands long-distance connections. this short review, we summarize state art EEG-based research paradigm, context providing potential support traditional clinical consciousness.

Language: Английский

---