An electrophysiological marker of arousal level in humans

eLife, Journal Year: 2020, Volume and Issue: 9

Published: July 28, 2020

Deep non-rapid eye movement sleep (NREM) and general anesthesia with propofol are prominent states of reduced arousal linked to the occurrence synchronized oscillations in electroencephalogram (EEG). Although rapid (REM) is also associated diminished levels, it characterized by a desynchronized, ‘wake-like’ EEG. This observation implies that not necessarily only defined synchronous oscillatory activity. Using intracranial surface EEG recordings four independent data sets, we demonstrate 1/f spectral slope electrophysiological power spectrum, which reflects non-oscillatory, scale-free component neural activity, delineates wakefulness from anesthesia, NREM REM sleep. Critically, discriminates solely based on neurophysiological brain state. Taken together, our findings describe common marker tracks arousal, including different stages as well humans.

Language: Английский

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Decomposing alpha and 1/f brain activities reveals their differential associations with cognitive processing speed

NeuroImage, Journal Year: 2019, Volume and Issue: 205, P. 116304 - 116304

Published: Oct. 22, 2019

Research in cognitive neuroscience has extensively demonstrated that the temporal dynamics of brain activity are associated with functioning. The mainly include oscillatory and 1/f noise-like, non-oscillatory activities coexist many forms confound each other's variability. As such, observed functional associations narrowband oscillations might have been confounded broadband component. Here, we investigated relationship between resting-state EEG efficiency functioning N = 180 individuals. We show plays an essential role accounting for between-person variability speed – a can be mistaken as originating from using conventional power spectrum analysis. At first glance, alpha appeared to predictive speed. However, when dissociating pure activity, only predicted speed, whereas vanished. With this highly powered study, disambiguate relevance law pattern resting state neural substantiate necessity isolating component studying spontaneous activities.

Language: Английский

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Towards a Comprehensive Understanding of Anesthetic Mechanisms of Action: A Decade of Discovery

Trends in Pharmacological Sciences, Journal Year: 2019, Volume and Issue: 40(7), P. 464 - 481

Published: May 27, 2019

Language: Английский

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Modality-specific tracking of attention and sensory statistics in the human electrophysiological spectral exponent

eLife, Journal Year: 2021, Volume and Issue: 10

Published: Oct. 21, 2021

A hallmark of electrophysiological brain activity is its 1/f-like spectrum – power decreases with increasing frequency. The steepness this ‘roll-off’ approximated by the spectral exponent, which in invasively recorded neural populations reflects balance excitatory to inhibitory (E:I balance). Here, we first establish that exponent non-invasive electroencephalography (EEG) recordings highly sensitive general (i.e., anaesthesia-driven) changes E:I balance. Building on EEG as a viable marker E:I, then demonstrate sensitivity focus selective attention an experiment during participants detected targets simultaneous audio-visual noise. In addition these endogenous balance, exponents over auditory and visual sensory cortices also tracked stimulus exponents, respectively. Individuals’ degree stimulus–brain coupling predicted behavioural performance. Our results highlight rich information contained activity, providing window into diverse processes previously thought be inaccessible human recordings.

Language: Английский

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Clinical and advanced neurophysiology in the prognostic and diagnostic evaluation of disorders of consciousness: review of an IFCN-endorsed expert group

Clinical Neurophysiology, Journal Year: 2020, Volume and Issue: 131(11), P. 2736 - 2765

Published: Aug. 14, 2020

The analysis of spontaneous EEG activity and evoked potentials is a cornerstone the instrumental evaluation patients with disorders consciousness (DoC). past few years have witnessed an unprecedented surge in EEG-related research applied to prediction detection recovery after severe brain injury, opening up prospect that new concepts tools may be available at bedside. This paper provides comprehensive, critical overview both consolidated investigational electrophysiological techniques for prognostic diagnostic assessment DoC. We describe conventional clinical approaches, then focus on event-related potentials, finally we analyze potential novel findings. In doing so, (i) draw distinction between acute, prolonged chronic phases DoC, (ii) attempt relate findings underlying neuronal processes (iii) discuss technical conceptual caveats. primary aim this narrative review bridge gap standard emerging measures consciousness. ultimate scope provide reference common ground academic researchers active field neurophysiology clinicians engaged intensive care unit rehabilitation.

Language: Английский

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Periodic and aperiodic neural activity displays age-dependent changes across early-to-middle childhood

Developmental Cognitive Neuroscience, Journal Year: 2022, Volume and Issue: 54, P. 101076 - 101076

Published: Jan. 22, 2022

The neurodevelopmental period spanning early-to-middle childhood represents a time of significant growth and reorganisation throughout the cortex. Such changes are critical for emergence maturation range social cognitive processes. Here, we utilised both eyes open closed resting-state electroencephalography (EEG) to examine maturational in oscillatory (i.e., periodic) non-oscillatory (aperiodic, '1/f-like') activity large cohort participants ranging from 4-to-12 years age (N = 139, average age=9.41 years, SD=1.95). EEG signal was parameterised into aperiodic periodic components, linear regression models were used evaluate if chronological could predict exponent offset, as well peak frequency power within alpha beta ranges. Exponent offset found decrease with age, while aperiodic-adjusted increased age; however, there no association between band. Age also unrelated spectral either or bands, despite ranges being correlated signal. Overall, these results highlight capacity features elucidate age-related functional developing brain.

Language: Английский

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Separating Neural Oscillations from Aperiodic 1/f Activity: Challenges and Recommendations

Neuroinformatics, Journal Year: 2022, Volume and Issue: 20(4), P. 991 - 1012

Published: April 7, 2022

Electrophysiological power spectra typically consist of two components: An aperiodic part usually following an 1/f law [Formula: see text] and periodic components appearing as spectral peaks. While the investigation parts, commonly referred to neural oscillations, has received considerable attention, study only recently gained more interest. The is quantified by center frequencies, powers, bandwidths, while parameterized y-intercept exponent text]. For either part, however, it essential separate components. In this article, we scrutinize frequently used methods, FOOOF (Fitting Oscillations & One-Over-F) IRASA (Irregular Resampling Auto-Spectral Analysis), that are from component. We evaluate these methods using diverse obtained with electroencephalography (EEG), magnetoencephalography (MEG), local field potential (LFP) recordings relating three independent research datasets. Each method each dataset poses distinct challenges for extraction both parts. specific features hindering separation highlighted simulations emphasizing features. Through comparison simulation parameters defined a priori, parameterization error quantified. Based on real simulated spectra, advantages discuss common challenges, note which impede separation, assess computational costs, propose recommendations how use them.

Language: Английский

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Consciousness among delta waves: a paradox?

Brain, Journal Year: 2021, Volume and Issue: 144(8), P. 2257 - 2277

Published: March 6, 2021

A common observation in EEG research is that consciousness vanishes with the appearance of delta (1-4 Hz) waves, particularly when those waves are high amplitude. High amplitude oscillations frequently observed states diminished consciousness, including slow wave sleep, anaesthesia, generalized epileptic seizures, and disorders such as coma vegetative state. This strong correlation between loss thought to stem from widespread cortical deactivation occurs during 'down states' or troughs these oscillations. Recently, however, many studies have reported presence prominent activity conscious states, which casts doubt on hypothesis an indicator unconsciousness. These include work Angelman syndrome, epilepsy, behavioural responsiveness propofol postoperative delirium, dissociation environment dreaming powerful psychedelic states. The foregoing complement older, yet largely unacknowledged, body literature has documented awake, patients clinical reports Rett Lennox-Gastaut schizophrenia, mitochondrial diseases, hepatic encephalopathy, non-convulsive status epilepticus. At same time, a parallel recent convincing evidence complexity entropy magnetoencephalographic signals strongly relates individual's level consciousness. Having reviewed this literature, we discuss plausible mechanisms would resolve seeming contradiction We also consider implications concerning theories integrated information theory entropic brain hypothesis. Finally, conclude false inferences unconscious can be best avoided by examining measures electrophysiological addition spectral power.

Language: Английский

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Consciousness and complexity: a consilience of evidence

Neuroscience of Consciousness, Journal Year: 2021, Volume and Issue: 2021(2)

Published: Jan. 1, 2021

Over the last years, a surge of empirical studies converged on complexity-related measures as reliable markers consciousness across many different conditions, such sleep, anesthesia, hallucinatory states, coma, and related disorders. Most these were independently proposed by researchers endorsing disparate frameworks employing methods techniques. Since this body evidence has not been systematically reviewed coherently organized so far, positive trend remained somewhat below radar. The aim paper is to make consilience in science explicit. We start with systematic assessment growing literature identify their common denominator, tracing it back core theoretical principles predictions put forward more than 20 years ago. In doing this, we highlight consistent trajectory spanning two decades research provide provisional taxonomy present literature. Finally, consider all above ground approach new questions devise future experiments that may help consolidate further develop promising field where appears have, naturally converged.

Language: Английский

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An increase of inhibition drives the developmental decorrelation of neural activity

eLife, Journal Year: 2022, Volume and Issue: 11

Published: Aug. 17, 2022

Throughout development, the brain transits from early highly synchronous activity patterns to a mature state with sparse and decorrelated neural activity, yet mechanisms underlying this process are poorly understood. The developmental transition has important functional consequences, as latter is thought allow for more efficient storage, retrieval, processing of information. Here, we show that, in mouse medial prefrontal cortex (mPFC), during first two postnatal weeks decorrelates following specific spatial patterns. This accompanied by concomitant tilting excitation-inhibition (E-I) ratio toward inhibition. Using optogenetic manipulations network modeling, that phenomena mechanistically linked, relative increase inhibition drives decorrelation activity. Accordingly, mice mimicking etiology neurodevelopmental disorders, subtle alterations E-I associated impairments correlational structure spike trains. Finally, capitalizing on EEG data newborn babies, an analogous takes place also human brain. Thus, changes control (de)correlation and, these means, its imbalance might contribute pathogenesis disorders.

Language: Английский

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