Figure 3.

Variation in mEPs. LFP amplitude in the time domain was averaged across all successful trials of each movement type to generate mEPs for two channels from the same recording session in monkey Y: one channel in array G (top) and another in array J (bottom) indicated with arrows in Figure 2. Separate mEPs were formed by averaging data aligned at the cue (A), OM (B), or SH (C). The mEPs in the two channels differed in many respects but had a number of general similarities. An early negative trough and positive peak were evident shortly after the cue. OM was preceded by a second negative peak. By the time of SH, the average traces in both monkeys were significantly different depending on the object. Similar results could be observed in population averages for all recording sessions (data not shown). The modulation of LFP amplitude in all recorded channels showed significant movement type × time interactions (two-way ANOVA, p < 0.01).