Measures of Entropy and Complexity in altered states of consciousness
Diego M. Mateos, Ramon Guevara Erra, Richard Wennberg, J. L. Perez Velazquez
arXiv Preprint Archive January 9, 2017 preprint
Study at a glance
AI-extracted from the abstract| Characteristics | Observational study |
|---|---|
| Population | Human subjects during awake, sleep stages, and epileptic seizures |
| Topics | Altered states of consciousness |
| Keywords | Q-bio.nc Cond-mat.stat-mech Consciousness Brain complexity Statistical physics |
| Key findings | Entropy and complexity of brain signals are greatest during wakefulness and decrease during states with loss of awareness or consciousness. |
Abstract
Quantification of complexity in neurophysiological signals has been studied using different methods, especially those from information or dynamical system theory. These studies revealed the dependence on different states of consciousness, particularly that wakefulness is characterized by larger complexity of brain signals perhaps due to the necessity of the brain to handle varied sensorimotor information. Thus these frameworks are very useful in attempts at quantifying cognitive states. We set out to analyze different types of signals including scalp and intracerebral electroencephalography (EEG), and magnetoencephalography (MEG) in subjects during different states of consciousness: awake, sleep stages and epileptic seizures. The signals were analyzed using a statistical (Permutation Entropy) and a deterministic (Permutation Lempel Ziv Complexity) analytical method. The results are presented in a complexity vs entropy graph, showing that the values of entropy and complexity of the signals tend to be greatest when the subjects are in fully alert states, falling in states with loss of awareness or consciousness. These results are robust for all three types of recordings. We propose that the investigation of the structure of cognition using the frameworks of complexity will reveal mechanistic aspects of brain dynamics associated not only with altered states of consciousness but also with normal and pathological conditions.
Comparable studies
Other observational and cohort studies on altered states of consciousness, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| Neural correlates of the DMT experience assessed with multivariate EEG. 6 female, 7 male human participants | 2019 | Observational cohort | n = 13 |
| Measures of entropy and complexity in altered states of consciousness Subjects during resting wakefulness, different sleep stages, and epileptic seizures | 2017 | Observational study | |
| Altered States of Consciousness and Short-Term Psychological After-Effects Induced by the First Time Ritual Use of Ayahuasca in an Urban Context in Brazil First-time ayahuasca users in Santo Daime and União do Vegetal rituals | 2005 | Observational cohort | n = 28 |
| Quantifying arousal and awareness in altered states of consciousness using interpretable deep learning Healthy individuals during sleep, individuals under general anesthesia, and patients... | 2022 | Observational cohort | n = 71 |
| Subanaesthetic ketamine and altered states of consciousness in humans Human volunteers | 2018 | Observational study | n = 15 |