Mapping the dynamics of consciousness: A unified account of variability in responsiveness across the spectrum of consciousness in health and disease

The unconscious brain’s ability to detect and identify stimuli is essential for our and our loved ones’ survival. For example, recognizing the smell of a fire or our baby's cry. What determines if and how the unconscious brain processes and reacts to information from the environment? As consciousness level diminishes (e.g., during sleep or following brain injury), slow wave activity (SWA) increases, weakening the input-output relationship and increasing response variability. Surprisingly, no study to date has adopted a variability-based approach to responsiveness, seeking common principles that persist across the spectrum of consciousness in both health and disease.DynamiConsciousness introduces a novel principled framework positing that SWA regionality (i.e., topography across regions) governs responsiveness variability across natural and pathological unconsciousness. I hypothesize that (1) SWA regionality nonlinearly modulates stimulus-induced intra-individual variability (IIV), exhibiting an inverted U-shape relationship, (2) Brain network dynamics is shaped by SWA and govern IIV in a modality-dependent manner, and (3) that IIV can predict consciousness recovery dynamics at the individual level. These hypotheses will be tested through multimodal experiments tailored for altered states of consciousness and by quantifying variability across modalities and time scales in healthy participants (sleep studies) and disorders of consciousness patients (longitudinal study). This interdisciplinary project, combining electrophysiology, neuroimaging, and physiology, offers a new unified framework for understanding responsiveness across the consciousness spectrum by linking within-person variability and SWA regionality. This approach will provide a unique lens for understanding brain functionality and promote a paradigm shift in the way we conceptualize and study consciousness.