Fig. 16.

An example of the activity of a GPi cell recorded simultaneously with tremor. The recordings are from monkey I in the MPTP-treated state. A, D, Five seconds of simultaneous recordings. The top trace is the spike train, the middle trace is the spike train smoothed with a digital Hamming window 20 msec wide, and the bottom trace is the accelerometer output. B,E, One second of data from A andD. It can be seen in B that the spike train and the tremor are correlated, whereas in E they are not. C, F, Power spectra of the two signals and their coherence function. The spectral analysis was performed over the entire recording segments (23.8 and 34.7 sec for theleft and right segments, respectively).