[Investigation of features of EEG changes at psychomotor disturbanses associated with microsleep]

We tested our earlier suggested hypothesis that one of mechanisms for failures of performance of behavioural tasks during microsleep is a spontaneous generation of ponto-geniculo-occipital (PGO) waves that suppress transmission of visual information from the retina via lateral geniculate nucleus to primary visual cortical areas and the striatum, and therefore significantly impair visual perception and attention. Experiments were done during the nighttime. Monotonic testing during performance of the two-alternative psychomotor test invoked participants into a state defined as a microsleep with open eyes. For each participant we made a comparative analysis of intensity of EEG spectrum during state of microsleep with open eyes when failure in test performance occurred and during accurate performance in waking state. Following trends in changes of EEG spectrum were found: increase in intensity of low alpha-range, and decrease in intensity of high alpha- and beta-ranges. Changes in theta-, low beta- and gamma-ranges were differently directed. Taking into account the known from the literature data these changes specify decrease in activation of primary visual cortical areas. Revealed data could support our hypothesis concerning mechanism of visual-motor disturbances during microsleep with open eyes.