Figure 3. Stimulus-triggered averages of LFP.

A, B and C, sample traces of LFP aligned to the PT stimulus, recorded during three different trials (150 μA; monkey M35). Single stimuli were delivered to the PT ipsilateral to the recording site during the hold period. Note that a complex wave was evoked by the PT shock, irrespective of whether there was on-going oscillatory activity before the stimulus (B and C) or not (A). Resetting of the on-going activity is demonstrated by rhythmic activity in traces B and C being out of phase before the stimulus, but in phase after it (filled circles indicate peaks of trace B, open circles indicate peaks of trace C). D, average of 110 traces shows phase locking of LFP for 100-150 ms after the stimulus. E, stimulus-triggered average for contralateral PT stimulation (150 μA, 110 trials) showed no effect.