Increased Sensitivity of Spatial Filters by Combining the Magnetic and Electrical Components of the Sensorimotor Cortical Beta RhythmстатьяИсследовательская статья
Информация о цитировании статьи получена из
Scopus
Статья опубликована в журнале из списка Web of Science и/или Scopus
Дата последнего поиска статьи во внешних источниках: 17 апреля 2024 г.
Аннотация:Modulation of human magnetic or electrical sensorimotor rhythms during motor imagery is widely used in fundamental and applied neurophysiological research. To date, there is evidence of a better sensitivity of magnetic field sensors to beta-rhythm modulation; however, the potential synergistic effect of combining the two modalities has not yet been investigated. In this study, simultaneous registration of an electroencephalogram (EEG) and a magnetoencephalogram (MEG) was carried out in eight healthy volunteers during voluntary and imaginary movements as well as during electrical stimulation of the median nerve. In all subjects it was possible to identify desynchronization (suppression) of µ- and β-rhythms during the performance of sensorimotor tasks as well as β-synchronization after the end of movement or stimulation. Using the common projections of the covariance signal matrices of the electric, magnetic, and combined (MEEG) modalities, the most sensitive individual spatial filters were calculated separately for each type of reaction. Relative to the prestimulus control, the amplitude of changes in the amplitude of sensorimotor rhythm components was found to be the largest in the combined MEEG modality. At the same time, for µ-desynchronization, MEG turned out to be significantly worse than MEEG; as for β-desynchronization, MEEG was shown to be significantly better than MEG and EEG. For β-synchronization, a shift in the position of sources in the fronto-medial direction was demonstrated, and there were no significant differences in amplitude between the modalities. It was also shown that, for β-desynchronization, most subjects identified MEG sources with identical EEG projections or without pronounced EEG projections, which indicated the presence of several small tangentially located cortical dipoles involved in β-rhythm desynchronization. The results suggested that the combination of MEG and EEG led to greater sensitivity in studies of modulation of sensorimotor rhythm components, in particular β-desynchronization. The multifocal nature of the magnetic β-rhythm and its different expression in EEG sources indicated the presence of independent regulatory circuits of cortical-thalamic or intracortical origin.