Similarly, for average-referenced ERPs, there were no significant main effects (all F[1, 37] ≤ 1.7 , all p ≥ .20) or interactions (all p ≥ .22) involving group. However, in contrast to linked mastoids, N1 amplitude showed a highly significant monotonic increase with intensity, F(2, 74) = 7.26, p = .001, ε = 0.9920, with means more than doubled (weak to strong, −2.22 ± 1.54, −2.46 ±1.40, −2.9 ± 1. 3 µV). There was also a significant left-greater-than-right N1 asymmetry, F(1, 37) = 6.00, p = .02. While there were no significant effects for N1 latency, N1 peaks were over 120 ms delayed compared to linked-mastoid ERPs (patients vs. controls, 463 ±134 vs. 445 ±136 ms; weak to strong, 470 ±139, 450 ±132, 444 ±133 ms). For P2 amplitude, highly significant main effects of intensity, F(2, 74) = 15.7, p < .0001, ε = 0.9022, and site, F(1, 37) = 5.58, p = .02, were comparable to those found for linked mastoids, but amplitudes were substantially smaller (weak to strong, 5.77 ±3.38, 6.06 ±2.92, 7.33 ±3.01 µV; z vs. Pz,
