Scientific Reports
September 24, 2025
Imad J. Bajwa, André Sevenius Nilsen, René Skukies et al.
3 citations
Abstract Patients undergoing general anesthesia are often assumed to be unconscious. However, it is known that conscious experiences in the form of dreams occur even in unresponsive states induced by anesthetics. Here, we recorded resting state electroencephalography (EEG) as well as EEG combined with TMS perturbations in 20 healthy participants during propofol sedation. Participants were...
Nature Communications
August 13, 2025
William Wong, Rubén Herzog, Kátia Cristine Andrade et al.
10 citations
Magneto/electroencephalography (M/EEG) studies of dreaming are an essential paradigm in the investigation of neurocognitive processes of human consciousness during sleep, but they are limited by the number of observations that can be collected per study. Dream research also involves substantial methodological and conceptual variability, which poses problems for the integration of results. To...
Brain Sciences
September 13, 2024
André Sevenius Nilsen, Johan Frederik Storm, Bjørn Erik Juel
Developing and testing methods for reliably measuring the state of consciousness of individuals is important for both basic research and clinical purposes. In recent years, several promising measures of consciousness, grounded in theoretical developments, have been proposed. However, the degrees to which these measures are affected by changes in brain activity that are not related to changes in...
Neuroscience of Consciousness
2024
André Sevenius Nilsen, Alessandro Arena, Johan F. Storm
10 citations
To investigate mechanisms underlying loss of consciousness, it is important to extend methods established in humans to rodents as well. Perturbational complexity index (PCI) is a promising metric of "capacity for consciousness" and is based on a perturbational approach that allows inferring a system's capacity for causal integration and differentiation of information. These properties have been...
May 16, 2023
William Wong, Kátia C. Andrade, Thomas Andrillon et al.
21 citations
preprint
Magneto/electroencephalography (M/EEG) studies of dreaming are an essential paradigm in the investigation of neurocognitive processes of human consciousness during sleep, but they are limited by the number of observations that can be collected per study. Dream research also involves substantial methodological and conceptual variability, which poses problems for the integration of results. To...
Frontiers in Human Neuroscience
2022
André Sevenius Nilsen, Bjørn E. Juel, Benjamin Thürer et al.
36 citations
In the field of consciousness science, there is a tradition to categorize certain states such as slow-wave non-REM sleep and deep general anesthesia as "unconscious". While this categorization seems reasonable at first glance, careful investigations have revealed that it is not so simple. Given that (1) behavioral signs of (un-)consciousness can be unreliable, (2) subjective reports of...
Frontiers in Human Neuroscience
2022
Arnfinn Aamodt, André Sevenius Nilsen, Rune Markhus et al.
29 citations
In a recent electroencephalography (EEG) sleep study inspired by complexity theories of consciousness, we found that multi-channel signal diversity progressively decreased from wakefulness to slow wave sleep, but failed to find any significant difference between dreaming and non-dreaming awakenings within the same sleep stage (NREM2). However, we did find that multi-channel Lempel-Ziv...
Frontiers in Psychology
April 23, 2021
Arnfinn Aamodt, André Sevenius Nilsen, Benjamin Thürer et al.
24 citations
Several theories link consciousness to complex cortical dynamics, as suggested by comparison of brain signal diversity between conscious states and states where consciousness is lost or reduced. In particular, Lempel-Ziv complexity, amplitude coalition entropy and synchrony coalition entropy distinguish wakefulness and REM sleep from deep sleep and anesthesia, and are elevated in psychedelic...
Entropy (Basel, Switzerland)
May 24, 2019
André Sevenius Nilsen, Bjørn Erik Juel, William Marshall
Integrated information theory (IIT) proposes a measure of integrated information, termed Phi (Φ), to capture the level of consciousness of a physical system in a given state. Unfortunately, calculating Φ itself is currently possible only for very small model systems and far from computable for the kinds of system typically associated with consciousness (brains). Here, we considered several...