Intracranial high-γ connectivity distinguishes wakefulness from sleep.
Neuroimage April 1, 2018 Ezequiel Mikulan, Eugenia Hesse, Lucas Sedeño et al.
Gamma-band neural synchrony is thought to be important for cortical computation and consciousness, but prior evidence has been inconclusive due to methodological issues. By using intracranial EEG in three participants with implanted electrodes, researchers compared high-gamma connectivity (90-120 Hz) during passive wakefulness versus non-REM sleep. Connectivity and graph-theory measures were higher during wakefulness and distinguished the two states better than other frequency bands. This is the first intracranial EEG report of wake-sleep differences in high-gamma activity at both local and distant brain sites, highlighting the technique's value for studying neural correlates of consciousness.