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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Spectral Slope and Lempel–Ziv Complexity as Robust Markers of Brain States during Sleep and Wakefulness

eNeuro, Journal Year: 2024, Volume and Issue: 11(3), P. ENEURO.0259 - 23.2024

Published: March 1, 2024

Nonoscillatory measures of brain activity such as the spectral slope and Lempel–Ziv complexity are affected by many neurological disorders modulated sleep. A multitude frequency ranges, particularly a broadband (encompassing full spectrum) narrowband approach, have been used especially for estimating slope. However, effects choosing different ranges not yet explored in detail. Here, we evaluated impact sleep stage task engagement (resting, attention, memory) on (30–45 Hz) (1–45 range 28 healthy male human subjects (21.54 ± 1.90 years) using within-subject design over 2 weeks with three recording nights days per subject. We strived to determine how states affect two perform comparison. In range, steepened, decreased continuously from wakefulness N3 REM sleep, however, was best discriminated Importantly, also differed between tasks during wakefulness. While engagement, flattened both ranges. Interestingly, only positively correlated performance. Our results show that sensitive indices state variations yields more information could be greater variety research questions than complexity, when is used.

Language: Английский

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Pupil size reveals arousal level fluctuations in human sleep

Nature Communications, Journal Year: 2025, Volume and Issue: 16(1)

Published: Feb. 28, 2025

Abstract Recent animal research has revealed the intricate dynamics of arousal levels that are important for maintaining proper sleep resilience and memory consolidation. In humans, changes in level believed to be a determining characteristic healthy pathological but tracking fluctuations been methodologically challenging. Here we measured pupil size, an established indicator levels, by safely taping right eye open during overnight tested whether size affects cortical response auditory stimulation. We show change as function events across different temporal scales. particular, our results inversely related occurrence spindle clusters, marker resilience. Additionally, found prior stimulation influence evoked response, most notably delta power, several restorative regenerative functions sleep. Recording provides insights into interplay between oscillations.

Language: Английский

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Decreased aperiodic neural activity in Parkinson’s disease and dementia with Lewy bodies

Journal of Neurology, Journal Year: 2023, Volume and Issue: 270(8), P. 3958 - 3969

Published: May 3, 2023

Language: Английский

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Fundamentals of sleep regulation: Model and benchmark values for fractal and oscillatory neurodynamics

Progress in Neurobiology, Journal Year: 2024, Volume and Issue: 234, P. 102589 - 102589

Published: March 1, 2024

Homeostatic, circadian and ultradian mechanisms play crucial roles in the regulation of sleep. Evidence suggests that ratios low-to-high frequency power electroencephalogram (EEG) spectrum indicate instantaneous level sleep pressure, influenced by factors such as individual sleep-wake history, current stage, age-related differences brain topography characteristics. These effects are well captured reflected spectral exponent, a composite measure constant ratio periodogram, which is scale-free exhibits lower interindividual variability compared to slow wave activity, potentially serving suitable standardization reference measure. Here we propose an index homeostasis based on reflecting membrane hyperpolarization and/or network bistability central nervous system humans. In addition, advance idea U-shaped overnight deceleration oscillatory fast spindle frequencies marks biological night, providing somnologists with EEG-index regulation. supporting this assertion comes from studies replacement, forced desynchrony protocols high-resolution analyses spindles. Finally, regulatory indicated recurrent, abrupt shifts dominant frequencies, ranges signifying non-rapid eye movement non-spindle oscillations – rapid phases cycles. Reconsidering indicators fundamental processes framework new Fractal Oscillatory Adjustment Model (FOAM) offers appealing opportunity bridge gap between two-process model clinical somnology.

Language: Английский

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Persistently increased post-stress activity of paraventricular thalamic neurons is essential for the emergence of stress-induced alterations in behaviour

PLoS Biology, Journal Year: 2025, Volume and Issue: 23(1), P. e3002962 - e3002962

Published: Jan. 21, 2025

A single exposure to a stressful event can result in enduring changes behaviour. Long-term modifications neuronal networks induced by stress are well explored but the initial steps leading these alterations remain incompletely understood. In this study, we found that acute triggers an immediate increase firing activity of calretinin-positive neurons paraventricular thalamic nucleus (PVT/CR+) persists for several days mice. This had causal role stress-induced spontaneous Attenuating PVT/CR+ only 1 h after rescued both protracted rate and behavioural alterations. Activation key forebrain targets (basolateral amygdala, prelimbic cortex, accumbens) mediate defensive behaviour has also been reduced post-stress inhibition. Reduction cell 5 later remained still effective ameliorating The results demonstrate critical prolonged, shaping associated with stress. Our data proposes therapeutic window intervention stress-related disorders, offering potential avenues targeted treatment strategies.

Language: Английский

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Scale-free and oscillatory spectral measures of sleep stages in humans

Frontiers in Neuroinformatics, Journal Year: 2022, Volume and Issue: 16

Published: Oct. 3, 2022

Power spectra of sleep electroencephalograms (EEG) comprise two main components: a decaying power-law corresponding to the aperiodic neural background activity, and spectral peaks present due oscillations. "Traditional" band-based methods ignore this fundamental structure EEG thus are susceptible misrepresenting underlying phenomena. A fitting method that attempts separate parameterize periodic components called "fitting oscillations one over f" (FOOOF) was applied set annotated whole-night recordings 251 subjects from wide age range (4-69 years). Most extracted parameters exhibited stage sensitivity; significant effects interactions stage, age, sex, brain region were found. The slope (describing steepness component) showed especially large consistent variability between stages (and low subjects), making it candidate indicator states. limitations arisen problems FOOOF also discussed, possible solutions for some them suggested.

Language: Английский

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The maturation of aperiodic EEG activity across development reveals a progressive differentiation of wakefulness from sleep

NeuroImage, Journal Year: 2023, Volume and Issue: 277, P. 120264 - 120264

Published: July 1, 2023

During development, the brain undergoes radical structural and functional changes following a posterior-to-anterior gradient, associated with profound of cortical electrical activity during both wakefulness sleep. However, systematic assessment developmental effects on aperiodic EEG maturation across vigilance states is lacking, particularly regarding its topographical aspects. Here, in population 160 healthy infants, children teenagers (from 2 to 17 years, 10 subjects for each year), we investigated development Specifically, parameterized shape background Power Spectral Density (PSD) by means spectral exponent offset; reflects rate exponential decay power over increasing frequencies offset an estimate y-intercept PSD. We found that sleep caused EEG-PSD rotate opposite directions: PSD showed flatter reduced while it steeper higher as becomes deeper. deep (N2, N3) only decreased age, indexing broad-band voltage reduction. As result, difference between values those light (N1) increased suggesting progressive differentiation from activity, most prominent frontal regions, latest complete maturation. Notably, stages were entirely separated values, consistently ages line previous findings adults. Concerning location showing steepest largest shifted posterior anterior regions age. This shift, evident sleep, paralleled migration slow wave was consistent neuroanatomical cognitive development. Overall, distinguishes regardless age; while, reveals postero-anterior Our study could help interpret due pathological conditions may elucidate neurophysiological processes underlying

Language: Английский

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The Temporal Dynamics of Aperiodic Neural Activity Track Changes in Sleep Architecture

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2024, Volume and Issue: unknown

Published: Jan. 26, 2024

Abstract The aperiodic (1/f-like) component of electrophysiological data - whereby power systematically decreases with increasing frequency, as quantified by the exponent has been shown to differentiate sleep stages. Earlier work, however, typically focused on measuring across a narrow frequency range. In this we sought further investigate activity during extending these analyses broader ranges and considering alternate model definitions. This included ‘knees’ in component, which reflect bends spectrum, indicating change exponent. We also evaluate temporal dynamics sleep. To do so, analyzed from two sources: intracranial EEG (iEEG) 106 epilepsy patients high-density 17 healthy individuals, measured activity, explicitly comparing different forms. doing find that fitting broadband models incorporating ‘knee’ feature effectively captures sleep-stage-dependent differences well relate stage transitions responses external stimuli. particular, knee parameter shows stage-specific variation, suggesting an interpretation varying timescales These results demonstrate examining more complex reveals novel insights interpretations for understanding neural

Language: Английский

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Overnight dynamics in scale-free and oscillatory spectral parameters of NREM sleep EEG

Scientific Reports, Journal Year: 2022, Volume and Issue: 12(1)

Published: Nov. 1, 2022

Abstract Unfolding the overnight dynamics in human sleep features plays a pivotal role understanding regulation. Studies revealed complex reorganization of frequency composition electroencephalogram (EEG) during course sleep, however scale-free and oscillatory measures remained undistinguished improperly characterized before. By focusing on first four non-rapid eye movement (NREM) periods night records 251 healthy subjects (4–69 years), here we reveal flattening spectral slopes decrease several intercepts consecutive cycles. Slopes are significant predictors slow wave activity (SWA), gold standard measure intensity. The increase peak sizes (amplitudes relative to spectra) broad sigma range is paralleled by U-shaped time frequencies frontopolar regions. Although, set indices analyzed herein reproduce known age- sex-effects, interindividual variability slope steepness lower as compared SWA. Findings indicate that distinct EEG could provide composite with low redundancy, potentially affording new insights into regulatory processes future studies.

Language: Английский

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