Neuroscience of consciousness
January 1, 2023
Sidath Rankaduwa, Adrian M Owen
21 citations
The entropic brain theory (EBT) explains how psychedelics alter brain activity by increasing brain entropy, offering insights into both normal and altered states of consciousness. This theory has implications for debates about whether consciousness exists in levels or dimensions, whether the psychedelic state represents a higher level of consciousness, and whether psychedelics could treat disorders of consciousness such as minimally conscious or vegetative states. The article summarizes EBT's core principles and their relevance to a theoretical model of consciousness, emphasizing that the therapeutic value of psychedelics for such patients depends on set and setting.
Scientific reports
June 7, 2021
Evan Houldin, Zhuo Fang, Laura B Ray et al.
17 citations
During sleep, functional connections between brain networks shift in a directional manner. In non-REM (NREM) sleep, positive wake-like correlations often become negative and strengthen in the opposite direction, while in REM sleep they trend back toward positive correlations. This pattern supports the idea that NREM sleep involves altered, not merely reduced, functional connectivity. Many of these connections involve higher-order networks linked to cognition and consciousness, such as the default mode network, suggesting possible accompanying changes in cognitive and conscious states.
eLife
July 18, 2024
Andrea I Luppi, Pedro A M Mediano, Fernando E Rosas et al.
1 citation
Loss of consciousness significantly disrupts the brain's ability to integrate information. In a study involving functional MRI analysis, it was revealed that gateway regions in a 'synergistic global workspace' correspond to the default mode network, while broadcaster regions align with the executive control network. This integration breakdown occurs during general anaesthesia or disorders of consciousness, with recovery restoring functionality. The findings enhance understanding of consciousness by bridging Global Neuronal Workspace and Integrated Information Theory, highlighting the critical role of brain networks in maintaining conscious experience.
Annals of clinical and translational neurology
May 25, 2025
Charlotte Maschke, Loretta Norton, Catherine Duclos et al.
In patients with severe brain injury, the neurological wake-up test—a brief interruption of sedation to check responsiveness—often yields ambiguous or absent behavioral responses, limiting its prognostic value. Recording 128-channel EEG from 41 such patients during propofol sedation interruption revealed that brain responses, measured by EEG power, spatial ratios, and the spectral exponent, can show signs of waking even when behavior does not. Combining EEG with behavioral assessment improved predictions of survival, recovery of consciousness, and long-term functional outcomes, outperforming the predictions of attending physicians. EEG can complement the wake-up test to better inform clinicians, families, and treatment planning.
Brain communications
January 1, 2026
Dorottya Szocs, Dian Lyu, Andrea I Luppi et al.
The pulvinar nucleus of the thalamus shows the strongest functional connectivity change with loss of consciousness under anesthesia in healthy volunteers, while the ventral-latero-ventral nucleus shows the strongest change in patients with disorders of consciousness. These nuclei exhibit distinct connectivity patterns with higher-order brain networks such as the default mode and executive control networks. In patients, the neural connectivity biomarker mirrored behavioral changes, suggesting potential clinical relevance for targeted deep brain stimulation therapy.
Communications biology
November 3, 2022
Peter Coppola, Judith Allanson, Lorina Naci et al.
Consciousness is associated with short-term brain connectivity transitions that are less predictable, quicker, but on average more constant than those in unconscious states. By combining modern consciousness theories with phenomenology and dynamical systems theory, the authors created an individual-specific landscape of brain connectivity dynamics as a proxy for the stream of consciousness. They found that temporally-specific connectivity states are less easily describable by network patterns distant in time, suggesting a richer space of possible states. The cortex, cerebellum, and subcortex all display consciousness-relevant dynamics.
Alzheimer's & dementia (New York, N. Y.)
January 1, 2021
Jonathan D Huntley, Stephen M Fleming, Daniel C Mograbi et al.
People with Alzheimer's disease show a range of changes in consciousness, including reduced awareness of cognitive deficits, diminished self-awareness, and impaired introspection, which appear early and worsen as the disease progresses. These awareness impairments are linked to brain damage in areas that overlap with proposed neural correlates of consciousness. The authors argue that recognizing Alzheimer's disease as a disorder of consciousness is overdue and important for understanding patients' lived experience and improving care.