EEG activities with open eyes in a quiet state (OA), during the pseudo-Raven's test (PRA), in hypnagogic state (HYP) and in the course of REM sleep (REM) are characteristic by nearly flat curves. We observed the states with eyes closed (OC), with hyperventilation (HV), during mental activity of calculation (CAL) and in NONREM 1 sleep (NR 1). 24 tested persons (probands) were investigated. We have found 8 typical states of EEG signals, which all have relation to attention and mental activity. Consequently, the EEG analysis can help in the differentiation between the above eight states. Using similar analyses, it is possible to discriminate all stages of NONREM and REM sleep without polysomnography.
Decrease of attention and an possible micro-sleep of an artificial system operator is very dangerous and its early detection can prevent great losses. This article deals with a classification of States of vigilance based on the analysis of an electroencefalographic activity of the brain. Preprocessing of data is done by the Discrete Fourier Transform. For the recognition radial basis functions (RBF), a k-nearest neighbor and a method based on the Bayesian theory is used. Its coefficients are found using the maximum likelihood estimation. An experiment with recognition of 6 States of vigilance created according to reaction time is performed.