Fig. 4.

Stimulus-evoked 16 Hz oscillations seen in the positive rebound phase of the response. A, Average time course for a cutaneous stimulation (n = 192 trials), depicting the appearance of oscillations. B,Power spectrum performed on rebound depolarization phase ofA (from t = 155 msec).C, Contour plot showing that the spatial extent of the 16 Hz oscillations amplitude in the rebound phase (red) is similar to the spatial extent of the response in the initial depolarization phase, for the same data as in A. D, Comparison of a typical single trial, showing both ongoing and evoked activity (green), to average response from 75 trials (blue). Large ongoing activity is detected only in the trial without signal averaging (arrow).