Dynamical independence reveals anaesthetic specific fragmentation of emergent structure in neural dynamics
Borjan Milinkovic, Anil K. Seth, Lionel Barnett, Olivia Carter, Thomas Andrillon
bioRxiv Preprint Server July 16, 2025 preprint DOI: 10.1101/2025.07.16.664881 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Observational study |
|---|---|
| Population | Human participants under anaesthesia |
| Interventions | propofol xenon ketamine |
| Topics | Addiction |
| Citations | 2 |
| Key findings | Propofol and xenon increase emergent but fragmented dynamical structure, whereas ketamine reduces emergence while partially preserving macroscopic organisation. |
Abstract
Conscious experience depends on the coordinated activity of neural processes that span multiple scales—from synapses to whole-brain dynamics. A recently introduced measure, dynamical independence, identifies, characterises and quantifies these multi-scale relationships using an information-theoretic dimensionality-reduction approach. Here, we use DI to examine changes in emergent dynamical structure in the human brain under three pharmacologically-distinct anaesthetic interventions (propofol, xenon, ketamine). Applied to source-reconstructed EEG, our analysis reveals that propofol and xenon, anaesthetics that abolish conscious report, exhibit more emergent but highly variable dynamic structure, indicating fragmented macroscopic dynamical organisation. By contrast, ketamine, which preserves dream-like phenomenology, shows the opposite pattern: reduced overall emergence yet a partial preservation of the macroscopic structure, mirroring wake. Further exploratory analyses revealed spatially localised source-level contributions to emergent dynamical structure, highlighting regional variations. Together, our results highlight drug-specific reconfigurations of emergent dynamical structure under anaesthesia, dissociate the amount of emergence from the organisation of emergent dynamics, and caution against equating emergence with level of consciousness.
Comparable studies
Other observational and cohort studies on addiction, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| Ayahuasca-Assisted Therapy for Addiction: Results from a Preliminary Observational Study in Canada Rural aboriginal population | 2013 | Observational study | |
| Dynamic coupling of whole-brain neuronal and neurotransmitter systems Healthy humans | 2020 | Observational study | |
| Psychedelics not linked to mental health problems or suicidal behavior: A population study Randomly selected United States adults | 2015 | Observational cohort | n = 135,095 |
| Breakdown of long-range temporal dependence in default mode and attention networks during deep sleep Human participants across the nonrapid eye movement sleep cycle | 2013 | Observational cohort | |
| Assessment of addiction severity among ritual users of ayahuasca Regular ayahuasca users (jungle-based and urban-based) and matched controls | 2010 | Observational cohort | n = 127 |