Do brain oscillations of different frequencies indicate interaction between cortical areas in humans?

Oscillatory cortical activity in the beta frequency range (14-32 Hz) was investigated in a voluntary movement task using closely-spaced electroencephalogram recordings over the sensorimotor cortex. According to recent studies, short-lasting beta oscillations were observed within the first second after termination of a self-paced finger movement. In this study we show, moreover, that finger movement creates beta bursts not only overlying the hand representation area, but also, at a higher frequency, over neighboring cortical areas representing the foot. The results indicate that, related to the same event, distinct cortical areas can display increased synchronized activity at different frequencies, providing evidence for interaction between the corresponding neuronal networks. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.