Reflections on the topics: EEG frequency bands and regulation of vigilance.

A critical analysis of quantitative pharmaco-electroencephalography begins with parametrization into variables. The determination of frequency bands according to clinical criteria should be reconsidered. Alternatives may be the determination of factor scores or the definition of frequency bands based on factor analysis. If the latter procedure is used, the clinical alpha-band is subdivided into a lower (alpha 1F = 8,5-10.5 HZ) and an upper (alpha 2F = 10.5-12.5 HZ) part. Furthermore parts of the clinical theta-band (and the delta-band are combined into the delta F-band (1.5-6.0 HZ), for awake healthy volunteers with an occipital alpha-rhythm. Existing concepts of vigilance for the awake stages are not contradictory to the following observations: the factor structure of EEG relative power spectrum variables shows a negative correlation of slow alpha-frequencies with those in the delta F- and beta 3F-band. There is also a negative correlation between slow and fast alpha-wave relative power values.