Correction of functional disturbances during pregnancy by the method of adaptive EEG biofeedback training

The applicability and efficiency of the electroencephalogram (EEG)-based method of biofeedback (BFB) training in correcting functional disorders in pregnancy have been evaluated in an obstetric/gynecological clinic in 65 pregnant women. Each of them took part in 2–12 examinations, which differed in voluntarily regulated EEG rhythm (a decrease in the θ, an increase in the α, or a decrease in the β rhythm), left-or right-hemispheric location of the EEG derivations, and the duration of the delay (3 or 30 s) of auditory feedback stimuli. As compared to the baseline, the most distinct and significant changes were observed in the α and θ rhythms during medical procedures, testifying to a general relaxing effect of the EEG BFB. The greatest number of successful trials (83.3 ± 4.4%) was observed for the BFB sessions aimed at decreasing the θ activity, and the lowest number (32.0 ± 6.7%), for the attempts at decreasing the EEG β rhythm. Voluntary control of the α rhythm of the EEG yielded a moderate number of successful trials (63.7 ± 5.3%), but it was characterized by the lowest efficiency (demonstrating minimal differences in positive changes in the functional state between successful and unsuccessful trials). The comparatively low effectiveness of voluntary BFB control of the α rhythm may have been determined by its high heterogeneity and suggests the necessity of using more narrowband EEG components in BFB sessions.