Computational Efficiency η and Neural Dissipation ||Δ|| During Propofol Sedation: EEG Evidence for the RDRT Consciousness Gradient
Zenodo (CERN European Organization for Nuclear Research) March 19, 2026 DOI: 10.5281/zenodo.19119371 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Observational cohort Peer reviewed |
|---|---|
| Sample size | 21 |
| Population | Human participants receiving propofol sedation |
| Intervention | Propofol |
| Keywords | Wakefulness Propofol Sedation Unconsciousness Electroencephalography Sedative Anesthesia Amplitude Artificial intelligence Dissipation Epilepsy Breathing |
| Key findings | Propofol sedation produces a massive reduction in computational efficiency η and a dramatic increase in dissipation norm ||Δ||, placing the sedated brain in a dissipative transition zone between wakefulness and deep unconsciousness. |
Abstract
Abstract We apply the Effective Power framework (Eff = Amp x Sgamma; Waterman 2026a) and the integrated scalar metrics η (computational efficiency) and ||Δ|| (dissipation norm) to a propofol sedation EEG dataset (ds005620; Bajwa et al. 2024, N=21, 65 channels). Recordings during wakefulness (eyes-closed resting) are compared with two levels of propofol sedation. The primary result is a massive reduction in η during sedation relative to wakefulness (awake: 0.893; sedated: 0.330; d=-2.151, p<0.001), accompanied by a dramatic increase in ||Δ|| (awake: 1.96 uV; sedated: 30.05 uV; d=+0.846, p<0.001). Pattern stability Sgamma collapses across all frequency bands during sedation (awake: 0.79-0.86; sedated: 0.06-0.38), while amplitude rises — particularly in delta and gamma bands. These results place propofol sedation in the dissipative transition zone of the η-||Δ|| phenomenal state space: low η combined with high ||Δ|| indicates that the sedated brain is expending substantial energy without producing organised spatial patterns. This is distinct from deep unconsciousness (where both η and ||Δ|| would approach zero) and from wakefulness (high η, low ||Δ||). The findings confirm the RDRT prediction (P4) that η monotonically decreases along the consciousness gradient, and establish sedation as an intermediate state in the phenomenal state space defined by η and ||Δ||. Combined with results from three previously analysed datasets (reversal learning, insight, meditation), these results establish η as a universal marker spanning both intra-conscious phenomenal transitions and the full consciousness-level gradient.