[EEG modeling by amplitude and phase radioelectric modulation. Consequences for morphological aspects of the signal (author's transl)].
An application of radioelectric modulation theory has been made on digital computer to simulate EEG-like signals. Both amplitude and phase time-series oscillating around a carrier frequency were computed. Such a model is non-linear and presents multiple solutions, nevertheless we have obtained the following results: 1) An additive model made of two EEG generators, 9.5 and 11.5 Hz, is equivalent to a 10.5 Hz one-generator multiplicative model which is modulated in amplitude by an envelope slowly oscillating around 1 Hz. 2) This first result is also valid for a phase modulated signal, sine-wave or random-like, with or without additive noise. 3) With a sine-wave phase modulation of high modulation index (5 to 10), the synthetized EEG signals appear visually similar to occipital posterior slow waves. 4) With a broad frequency-band sine-wave phase modulation centered around alpha frequency, the increase of modulation index (from 0.5 to 1) produces EEG-like signals visually similar to spiky irritative tracings. The general radioelectric modulation model named "emission and reception in diversity" can probably explain these diverse computerized EEG-like signals.
D003201:Computers; D004569:Electroencephalography; D006801:Humans; D008959:Models, Neurological
Modèle d'E.E.G. par modulation radioélectrique d'amplitude et de phase. Conséquences sur l'aspect morphologique du signal.