[fMRI-EEG study of healthy human brain responses to functional loads].

The functional magnetic resonance imaging (fMRI) and EEG responses to identical functional (visual and motor) loads have been compared in ten healthy subjects with the use of individual structural MRIs of the brain. It has been established that an increase in the coherence of the EEG α waves corresponds mostly to the zone of the fMRI response (as a +BOLD reaction). Reactive rearrangements, according to the data of fMRI and, particularly, EEG studies, are characterized by pronounced interindividual variation, which increases along with the functional test complexity. The fMRI responses have shown a greater locality and closer dependence on the modality of presented stimuli than EEG rearrangements, which underline the systemic character of brain response to functional loads. The −BOLD response accompanying the local +BOLD effect is more generalized, without distinct topographic referencing to the functional load modality; it conforms most of all to the decrease in the EEG’s coherence.