Figure 1

Data recorded at the right hand of a patient while the stimulator was switched off (DBSoff). The upper graph shows the PSDs of every 2 s-window of the recorded angular velocity (gray lines) and the average PSD of these windows (red line). All windows were in this case classified as tremor windows. The broken line indicates the frequency of the auditory cueing signal, i.e. 1.6 Hz. The lower graph shows the low frequency component of the angular velocity (red line), associated with voluntary movement performed by the hand. This movement component was extracted by filtering the angular velocity signal with a low pass filter (5th order non-causal Butterworth filter with a cut off frequency of 3.5 Hz) and normalizing the filtered signal to a range between -1 and 1. The cueing signal is represented by a 1.6 Hz sinusoidal signal (blue line) with an amplitude of 0.5. In addition, the PLV for the movement component of the angular velocity and the cueing signal (black markers connected by a linear line) is shown.