How hot is the hot zone? Computational modelling clarifies the role of parietal and frontoparietal connectivity during anaesthetic-induced loss of consciousness
Riku Ihalainen, Olivia Gosseries, Frederik van de Steen, Federico Raimondo, Rajanikant Panda, Vincent Bonhomme, Daniele Marinazzo, Howard Bowman, Steven Laureys, Srivas Chennu
Neuroimage February 9, 2021 DOI: 10.1016/j.neuroimage.2021.117841 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Observational cohort Peer reviewed |
|---|---|
| Sample size | 10 |
| Population | Humans undergoing propofol anaesthesia |
| Intervention | Propofol anaesthesia |
| Duration | 10 min of high-density EEG recordings during behavioural responsiveness, unconsciousness, and post-anaesthetic recovery |
| Topics | Default mode network |
| Keywords | Precuneus Unconsciousness Mind-wandering Posterior parietal cortex Task-positive network Salience neuroscience Resting State FMRI Posterior cingulate Cognitive psychology Cortex anatomy Cognition |
| Citations | 30 |
| Key findings | Loss of consciousness during propofol anaesthesia reduces inter-network connectivity in the parietal cortex, especially feed-forward frontoparietal and parietal connections at the precuneus node within the default mode network. |
Abstract
In recent years, specific cortical networks have been proposed to be crucial for sustaining consciousness, including the posterior hot zone and frontoparietal resting state networks (RSN). Here, we computationally evaluate the relative contributions of three RSNs - the default mode network (DMN), the salience network (SAL), and the central executive network (CEN) - to consciousness and its loss during propofol anaesthesia. Specifically, we use dynamic causal modelling (DCM) of 10 min of high-density EEG recordings (N = 10, 4 males) obtained during behavioural responsiveness, unconsciousness and post-anaesthetic recovery to characterise differences in effective connectivity within frontal areas, the posterior 'hot zone', frontoparietal connections, and between-RSN connections. We estimate - for the first time - a large DCM model (LAR) of resting EEG, combining the three RSNs into a rich club of interconnectivity. Consistent with the hot zone theory, our findings demonstrate reductions in inter-RSN connectivity in the parietal cortex. Within the DMN itself, the strongest reductions are in feed-forward frontoparietal and parietal connections at the precuneus node. Within the SAL and CEN, loss of consciousness generates small increases in bidirectional connectivity. Using novel DCM leave-one-out cross-validation, we show that the most consistent out-of-sample predictions of the state of consciousness come from a key set of frontoparietal connections. This finding also generalises to unseen data collected during post-anaesthetic recovery. Our findings provide new, computational evidence for the importance of the posterior hot zone in explaining the loss of consciousness, highlighting also the distinct role of frontoparietal connectivity in underpinning conscious responsiveness, and consequently, suggest a dissociation between the mechanisms most prominently associated with explaining the contrast between conscious awareness and unconsciousness, and those maintaining consciousness.
Comparable studies
Other observational and cohort studies on default mode network, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| A default mode of brain function Normal adult human brain | 2001 | Observational study | |
| Resting-State Functional Connectivity Reflects Structural Connectivity in the Default Mode Network Healthy subjects | 2008 | Observational cohort | |
| Meditation experience is associated with increased cortical thickness Participants with extensive Insight meditation experience and matched controls | 2005 | Observational cohort | n = 20 |
| Meditation experience is associated with differences in default mode network activity and connectivity Experienced meditators and matched meditation-naive controls | 2011 | Observational cohort | |
| The precuneus/posterior cingulate cortex plays a pivotal role in the default mode network: Evidence from a partial correlation network analysis Healthy subjects | 2008 | Observational study |
Citations in the library
Cited by 7
- The nature of consciousness in anaesthesia BJA Open September 26, 2023
- Investigating functional brain connectivity patterns associated with two hypnotic states Frontiers in Human Neuroscience December 19, 2023
- Unraveling the brain dynamics of Depersonalization-Derealization Disorder: a dynamic functional network connectivity analysis. BMC Psychiatry October 14, 2024
- Distinct Patterns of Directed Brain Connectivity in Focused Attention, Open Monitoring, and Loving Kindness Meditation: An Electroencephalographic Granger Causality Study with Long-term Meditators Journal of Cognitive Neuroscience 2026
- Consciousness in the Brain: An Integrative Review of Contemporary Theories. Brain Sciences July 14, 2026
and 2 more in the library
Cites 20
- Neural correlates of consciousness: progress and problems Nature Reviews Neuroscience April 20, 2016
- Decoupling of the brain's default mode network during deep sleep Proceedings of the National Academy of Sciences June 19, 2009
- Breakdown of within- and between-network Resting State Functional Magnetic Resonance Imaging Connectivity during Propofol-induced Loss of Consciousness Anesthesiology September 30, 2010
- Disruption of Frontal–Parietal Communication by Ketamine, Propofol, and Sevoflurane Anesthesiology May 22, 2013
- Intrinsic Brain Activity in Altered States of Consciousness Annals of the New York Academy of Sciences May 1, 2008
and 15 more in the library