Brain Complexity and Consciousness
What happens in the brain when we lose consciousness—during sleep, under anesthesia, or in coma? And what changes when consciousness expands, as in psychedelic states? These questions drive my neuroscience research.
I study how the complexity and information dynamics of brain activity relate to different states of awareness. Using tools from information theory and network science, I analyze neuroimaging data (fMRI, EEG, MEG) to understand how the brain’s functional organization shifts across states.
States of Consciousness
Reduced States
In states of reduced consciousness—deep sleep, sedation, disorders of consciousness—brain activity becomes more stereotyped and predictable. Information integration across brain regions decreases, and the rich, differentiated patterns of wakefulness give way to simpler dynamics.
Expanded States
Psychedelic compounds like LSD, psilocybin, and DMT produce profound alterations in consciousness characterized by increased entropy in brain activity, dissolution of typical network boundaries, and enhanced flexibility in neural dynamics. Understanding these changes offers insights into both the neurobiology of consciousness and potential therapeutic applications.
Key Questions
- How does information integration across brain regions relate to the level and quality of consciousness?
- What makes brain activity during wakefulness qualitatively different from unconscious states?
- Can we develop reliable biomarkers of consciousness for clinical applications?
- What do psychedelic-induced brain changes tell us about the neural correlates of consciousness?
Methods
- Neuroimaging analysis: Working with fMRI, EEG, and MEG data to characterize brain dynamics
- Information-theoretic measures: Applying entropy, complexity, and integration measures to neural data
- Network neuroscience: Analyzing the brain as a complex network with dynamic functional connectivity
- Computational modeling: Building models to test theories of consciousness
Selected Publications
- Varley, T. F., et al. (2020). “Fractal dimension of cortical functional connectivity networks and severity of disorders of consciousness.” PLOS ONE.
- Varley, T. F., et al. (2020). “Serotonergic psychedelics LSD & psilocybin increase the fractal dimension of cortical brain activity in spatial and temporal domains.” NeuroImage.
- Varley, T. F., et al. (2023). “Network analysis of time series: Novel approaches to network neuroscience.” Frontiers in Neuroscience.
For a complete list of publications, see my Google Scholar profile.