Cross-frequency decomposition: a novel technique for studying interactions between neuronal oscillations with different frequencies.
OBJECTIVE
We present a novel method for the extraction of neuronal components showing cross-frequency phase synchronization.


METHODS
In general the method can be applied for the detection of phase interactions between components with frequencies f1 and f2, where f2 ≈ rf1 and r is some integer. We refer to the method as cross-frequency decomposition (CFD), which consists of the following steps: (a) extraction of f1-oscillations with the spatio-spectral decomposition algorithm (SSD); (b) frequency modification of the f1-oscillations obtained with SSD; and (c) finding f2-oscillations synchronous with f1-oscillations using least-squares estimation.


RESULTS
Our simulations showed that CFD was capable of recovering interacting components even when the signal-to-noise ratio was as low as 0.01. An application of CFD to the real EEG data demonstrated that cross-frequency phase synchronization between alpha and beta oscillations can originate from the same or remote neuronal populations.


CONCLUSIONS
CFD allows a compact representation of the sets of interacting components. The application of CFD to EEG data allows differentiating cross-frequency synchronization arising due to genuine neurophysiological interactions from interactions occurring due to quasi-sinusoidal waveform of neuronal oscillations.


CONCLUSIONS
CFD is a method capable of extracting cross-frequency coupled neuronal oscillations even in the presence of strong noise.
Neurophysics Group, Department of Neurology, Campus Benjamin Franklin, Charité - University Medicine Berlin, D-12200 Berlin, Germany. vadim.nikulin@charite.de
Vadim V
VV
Nikulin
Guido
G
Nolte
Gabriel
G
Curio
D000465:Algorithms; D000513:Alpha Rhythm / Q000502:physiology; D001611:Beta Rhythm / Q000502:physiology; D001921:Brain / Q000502:physiology*; D003198:Computer Simulation; D004569:Electroencephalography / Q000379:methods*; D058407:Electroencephalography Phase Synchronization / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D009474:Neurons / Q000502:physiology*