Grand average of contralateral, ipsilateral, and contralateral-minus-ipsilateral waveforms for Experiment 1. Anterior waveforms are collapsed across electrode sites F3/4, F7/8, C3/4, T7/8. Posterior waveforms are collapsed across electrode sites P1/2, P3/4, P5/6, P7/8, P9/10, PO3/4, PO7/8, O1/2. For visual clarity, the waveforms shown here were filtered offline with a low-pass Gaussian filter with a half-amplitude cutoff at 50 Hz. The raw contralateral and ipsilateral waveforms use the 2.0 μV scale. The contralateral-minus-ipsilateral difference waveforms use the 1.0 μV scale.