Influence of passive thumb movements on μ wave

μ wave is the spontaneous EEG activity around 10Hz originating from Rolandic area and is suppressed by voluntary movements. The current study was designed to test whether μ wave was also suppressed by passive movements. The passive movements of right thumb (driven by a custom-made mechanism) of two different frequencies, namely, 5 and 10 Hz, were used as the sensory inputs. Sixteen channels of EEG signals in bilateral central area were recorded with a digital EEG machine with a sampling rate of 256 Hz. Two time-frequency signal processing methods, short time Fourier Transform and wavelet decomposition were employed to analyze the data. Three normal subjects were recruited. The results of both short time Fourier Transform and wavelet decomposition analyses indicated that μ wave on the contralateral somatosensory area was suppressed during passive movements.