Neural complexity is a common denominator of human consciousness across diverse regimes of cortical dynamics

Joel Frohlich; Jeffrey N Chiang; Pedro A M Mediano; Mark Nespeca; Vidya Saravanapandian; Daniel Toker; John Dell'Italia; Joerg F Hipp; Shafali S Jeste; Catherine J Chu; Lynne M Bird; Martin M Monti

doi:10.1038/s42003-022-04331-7

Neural complexity is a common denominator of human consciousness across diverse regimes of cortical dynamics

Commun Biol. 2022 Dec 15;5(1):1374. doi: 10.1038/s42003-022-04331-7.

Authors

Joel Frohlich^{1

2}, Jeffrey N Chiang³, Pedro A M Mediano^{4

5}, Mark Nespeca^{6

7}, Vidya Saravanapandian⁸, Daniel Toker⁹, John Dell'Italia¹⁰, Joerg F Hipp¹¹, Shafali S Jeste^{8

12}, Catherine J Chu¹³, Lynne M Bird^{14

15}, Martin M Monti^{9

16}

Affiliations

¹ Department of Psychology, University of California Los Angeles, 90095, Pritzker Hall, Los Angeles, CA, USA. jfneuro@pm.me.
² Institute for Neuromodulation and Neurotechnology, University Hospital and University of Tuebingen, Tuebingen, Germany. jfneuro@pm.me.
³ Department of Computational Medicine, University of California Los Angeles, Los Angeles, CA, USA.
⁴ Department of Computing, Imperial College London, London, UK.
⁵ Department of Psychology, University of Cambridge, Cambridge, UK.
⁶ Department of Neurosciences, University of California San Diego, San Diego, CA, USA.
⁷ Department of Neurology, Rady Children's Hospital San Diego, San Diego, CA, USA.
⁸ Center for Autism Research and Treatment, University of California Los Angeles, Semel Institute for Neuroscience, Los Angeles, CA, USA.
⁹ Department of Psychology, University of California Los Angeles, 90095, Pritzker Hall, Los Angeles, CA, USA.
¹⁰ Institute for Advanced Consciousness Studies, Santa Monica, CA, USA.
¹¹ Roche Pharma Research and Early Development, Neuroscience and Rare Diseases, Roche Innovation Center Basel, Basel, Switzerland.
¹² Children's Hospital Los Angeles, Los Angeles, CA, USA.
¹³ Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
¹⁴ Department of Pediatrics, University of California San Diego, San Diego, CA, USA.
¹⁵ Division of Genetics/Dysmorphology, Rady Children's Hospital - San Diego, San Diego, CA, USA.
¹⁶ Deptment of Neurosurgery, UCLA Brain Injury Research Center, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA.

Abstract

What is the common denominator of consciousness across divergent regimes of cortical dynamics? Does consciousness show itself in decibels or in bits? To address these questions, we introduce a testbed for evaluating electroencephalogram (EEG) biomarkers of consciousness using dissociations between neural oscillations and consciousness caused by rare genetic disorders. Children with Angelman syndrome (AS) exhibit sleep-like neural dynamics during wakefulness. Conversely, children with duplication 15q11.2-13.1 syndrome (Dup15q) exhibit wake-like neural dynamics during non-rapid eye movement (NREM) sleep. To identify highly generalizable biomarkers of consciousness, we trained regularized logistic regression classifiers on EEG data from wakefulness and NREM sleep in children with AS using both entropy measures of neural complexity and spectral (i.e., neural oscillatory) EEG features. For each set of features, we then validated these classifiers using EEG from neurotypical (NT) children and abnormal EEGs from children with Dup15q. Our results show that the classification performance of entropy-based EEG biomarkers of conscious state is not upper-bounded by that of spectral EEG features, which are outperformed by entropy features. Entropy-based biomarkers of consciousness may thus be highly adaptable and should be investigated further in situations where spectral EEG features have shown limited success, such as detecting covert consciousness or anesthesia awareness.

Trial registration: ClinicalTrials.gov NCT00296764.

Publication types

Research Support, Non-U.S. Gov't
Research Support, N.I.H., Extramural

MeSH terms

Child
Consciousness*
Electroencephalography / methods
Entropy
Humans
Sleep
Wakefulness*

Associated data

ClinicalTrials.gov/NCT00296764

Abstract

Publication types

MeSH terms

Associated data

Grants and funding