Interhemispheric phase synchrony and amplitude correlation of spontaneous beta oscillations in human subjects: a magnetoencephalographic study.
Interhemispheric phase synchrony and amplitude correlation of beta oscillations were studied with MEG in a resting condition. The left and right hemisphere beta oscillations exhibited phase-locking with a phase-lag near zero degrees. The index of synchronization was strongest when these oscillations had large amplitude. Functionally, we interpret the phase synchrony on the basis of bilaterality of movement organization. A positive interhemispheric correlation was also found for the amplitude of spontaneous beta oscillations over long time intervals (> 1 s). The low-frequency correlation of spontaneous rhythmic activity may be the source of the low-frequency correlations of the hemodynamic responses in homologous areas that have been reported previously and have been interpreted as functional connectivity between these areas.
Nikouline
V V
VV
BioMag Laboratory, Medical Engineering Centre, Helsinki University Central Hospital, Helsinki, PO Box 340, FIN-00029 HUS, Finland.
Linkenkaer-Hansen
K
K
Huttunen
J
J
Ilmoniemi
R J
RJ
D001611:Beta Rhythm; D002540:Cerebral Cortex / Q000502:physiology*; D006801:Humans; D015225:Magnetoencephalography; D010507:Periodicity; D012146:Rest / Q000502:physiology