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Related Experiment Video

Updated: May 23, 2026

Quantifying Infra-slow Dynamics of Spectral Power and Heart Rate in Sleeping Mice

Quantifying Infra-slow Dynamics of Spectral Power and Heart Rate in Sleeping Mice

Published on: August 2, 2017

Human gamma oscillations during slow wave sleep.

Mario Valderrama¹, Benoît Crépon, Vicente Botella-Soler

¹Institut National de la Santé et de la Recherche Médicale (INSERM) UMRS 975, Centre National de la Recherche Scientifique (CNRS)-UMR 7225, Université Pierre et Marie Curie (UPMC), Hôpital de la Pitié-Salpêtrière, Paris, France.

|April 13, 2012

Summary

This summary is machine-generated.

Gamma oscillations, high-frequency brain activity, were observed in human EEG during slow-wave sleep for the first time. These oscillations correlate with slow waves, suggesting a role in offline neural processing.

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Area of Science:

Neuroscience
Sleep Research
Electrophysiology

Background:

Gamma oscillations are known to occur during slow-wave sleep (SWS) in animal models.
Evidence for gamma oscillations at the macroscopic electroencephalogram (EEG) level in humans during SWS has been lacking.

Purpose of the Study:

To investigate the presence and characteristics of gamma oscillations in the human cerebral cortex during SWS using simultaneous scalp and intracranial EEG.
To determine the relationship between gamma oscillations and cortical slow waves during sleep.

Main Methods:

Simultaneous scalp and intracranial EEG recordings were performed in 20 epileptic subjects during SWS.
Analysis focused on identifying gamma oscillations (30-120 Hz) and their correlation with slow wave phases.

Main Results:

Gamma oscillations in low (30-50 Hz) and high (60-120 Hz) bands were recurrently observed across investigated cortical regions during SWS.
Two distinct patterns emerged: "IN-phase" (gamma bursts with positive slow wave peaks) and "ANTI-phase" (gamma bursts with negative slow wave peaks, prominent in temporal cortex).
Spatial coherence of gamma activity was found to be local, decreasing rapidly between distant cortical sites.

Conclusions:

This study provides the first human evidence of gamma oscillations detectable via macroscopic EEG during SWS.
These findings support the hypothesis that gamma oscillations are linked to phasic neural activity increases during slow oscillations.
Patterned gamma activity during sleep may contribute to offline processing within cortical networks.