[Quadri-dimensional analysis of the electroencephalography. First application to an episode of paradoxical sleep in man]. / Analyse quadri-dimensionnelle de l'électroencéphalogramme. Première application à un épisode de sommeil paradoxal chez l'Homme.

ABSTRACT

A first example of quadri-dimensional EEG analysis is presented which is characteristic of a series of ten analyses episodes of paradoxical sleep recorded in polygraphy during 5 nights' sleep in three human volunteers. A first EEG recording of wakefulness, eyes open, with visual fixation of a central point, was followed by a polygraphic night of sleep recording after habituation. The first subject was recorded during three nights; two other subjects during one night only after habituation. An EEG montage of 16 channels was quantified by spectral analysis and parametrization, after artefact rejection, for the reference sequence of wakefulness and further episodes of paradoxical sleep. After temporal and spatial interpolation algorithms, for each sequence, a series of root-mean-square successive EEG maps were computed and displayed, between 0.5 to 30 Hz. Low amplitude values of locally activated areas were chosen during the wakefulness EEG sequence and provided filtering thresholds for isolating activated areas during paradoxical sleep. The first 30 maps of each episode were piled up one on top of the other, along a vertical time axis, then dynamically visualised in colors and 3D. The "trajectories of activated areas" were then displayed in a quadri-dimensional functional space (x-y spatial map of the scalp; t time; color or black and white filtered or unfiltered rms EEG amplitudes). The EEG trajectories of awakened areas, appeared through time like unique "fibres" or double fibres after bifurcation. The unique fibres were located over left temporo-central activated areas and a double fibre appeared after bifurcation over the right parietal area.(ABSTRACT TRUNCATED AT 250 WORDS)