Premium
Fronto‐occipital EEG power gradients in human sleep
Author(s) -
WERTH ESTHER,
ACHERMANN PETER,
BORBÉLY ALEXANDER
Publication year - 1997
Publication title -
journal of sleep research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.297
H-Index - 117
eISSN - 1365-2869
pISSN - 0962-1105
DOI - 10.1046/j.1365-2869.1997.d01-36.x
Subject(s) - non rapid eye movement sleep , electroencephalography , sleep (system call) , k complex , sleep spindle , audiology , delta wave , psychology , nuclear magnetic resonance , physics , neuroscience , medicine , computer science , operating system
The brain topography of power spectra along the antero‐posterior (A‐P) axis was studied in the all‐night human sleep EEG. Spectra (0.25–25.0 Hz) were computed for an anterior ( A ; F3‐C3), a middle ( M ; C3‐P3) and a posterior ( P ; P3‐O1) bipolar derivation, and the spectral gradients between two adjacent derivations were expressed by power ratios ( A / M and M / P ). At NREM‐REM sleep transitions a power shift from A to M was present over almost the entire frequency range, while the direction of shifts between M and P differed between frequency bands. Within NREM sleep, frequency specific power gradients were present: In the low delta band power in both A (0.25 Hz bin) and P (0.25–1.0 Hz bins) was higher than in M . In the 4–9 Hz range the relation was A > M > P , and in the 15–25 Hz range power was largest in M . Power in the spindle frequency range was highest at 11.75 Hz in M , and at 13.5–13.75 Hz in A . Topographical differences were seen also in the temporal changes of power across and within NREM sleep episodes. Whereas NREM sleep power in the 2‐Hz bin was higher in A than in M in the first episode, this difference vanished in the course of the night. This result points to a specific involvement of frontal parts of the cortex in sleep homeostasis. The regional differences in sleep EEG spectra indicate that sleep is not only a global phenomenon but also a local brain process with a different regional involvement of neuronal populations.