Neurology
February 25, 2025
David Fischer, Brian L Edlow, Holly J Freeman et al.
9 citations
Some patients with severe brain injury who appear unresponsive can still show covert consciousness by intentionally modulating their brain activity in response to commands, as detected by fMRI or EEG. However, current methods for detecting this covert consciousness have important limitations: they are not sensitive enough, rely on assumptions about brain function that may be incorrect, and fail to capture the full range of conscious experience. Neural decoding, a technique that reconstructs stimuli and concepts from brain activity, offers a promising new approach that could overcome these shortcomings. This article reviews the current state of covert consciousness assessments, their limitations, the science of neural decoding, and how it might be applied to disorders of consciousness, suggesting that neural decoding could improve sensitivity and better address what patients can actually experience.
NeuroImage
May 15, 2025
Aya Khalaf, Erick Lopez, Jian Li et al.
6 citations
Subcortical arousal systems help control sustained changes in attention and conscious awareness, and recent studies suggest they also influence short-term dynamic modulation of visual attention, but their role across sensory modalities is unclear. Analyzing fMRI data from 1561 participants performing visual, auditory, tactile, and taste perception tasks, a shared circuit of subcortical arousal systems was identified. This circuit shows early transient increases in activity in the midbrain reticular formation and central thalamus across all sensory modalities, with less consistent increases in the pons, hypothalamus, basal forebrain, and basal ganglia. Identifying these networks is critical for understanding normal attention and consciousness and may aid subcortical targeting for therapeutic neuromodulation.
Nature and science of sleep
January 1, 2025
David R Schreier, Matteo Fecchio, Christian S Guay et al.
Dexmedetomidine (DEX) is a sedative that produces a sleep-like state and offers a way to study shifts in consciousness using behavior, EEG, and TMS-evoked EEG responses. Little is known about how repeated DEX exposure affects recovery. This pilot trial plans to sedate 12 healthy volunteers twice, one week apart, monitoring responsiveness with an auditory click task. It will compare time to return of responsiveness between visits, explore sex differences, and assess state transitions via EEG signatures, TMS-evoked complexity, and cognitive tests. The study also evaluates the feasibility of TMS-EEG during DEX sedation and reports on sleep quality and experiences.