Table 3.

Mean amplitudes and mean peak latencies of the P1, N1, and P2 components in the AIS control group.

	Mean amplitude (μV)		Peak latencies (ms)
	AIS	Control	AIS	Control
P1 (80–160 ms)
D1	5.15 ± 3.17	4.95 ± 2.87	143.56 ± 17.22	151.67 ± 13.98
D2	4.98 ± 3.06	5.01 ± 3.26	149.72 ± 18.85	150.36 ± 17.24
D3	4.63 ± 3.37	5.14 ± 2.90	143.40 ± 15.58	149.72 ± 13.41
N1 (100–200 ms)
D1	−2.52 ± 1.73	−1.52 ± 2.08	156.71 ± 10.60	147.89 ± 13.03
D2	−2.19 ± 2.29	−2.02 ± 2.19	154.26 ± 11.60	151.22 ± 14.05
D3	−3.10 ± 2.09	−2.51 ± 2.56	157.28 ± 11.24	154.94 ± 12.22
P2 (200–300 ms)
D1	6.57 ± 3.67	6.36 ± 3.67	244.15 ± 17.67	250.10 ± 15.88
D2	5.80 ± 2.92	5.75 ± 3.61	236.54 ± 20.28	246.18 ± 15.02
D3	4.07 ± 2.90	4.40 ± 3.15	238.64 ± 23.67	242.44 ± 17.54

D1: feet shoulder-width apart, D2: feet together, D3: tandem stance.

Values are expressed as mean ± SD. The mean amplitudes and peak latencies are the average of mean amplitudes and peak latencies of O1, OZ, and O2 electrodes for the P1 component; F3, FZ, F4, FCZ, and CZ electrodes for the N1 component; and P3, PZ, and P4 electrodes for the P2 component. Significance was only reported for the main effect of posture for the mean amplitudes of the P2 component (F = 14.39, p < 0.01). Subsequent post-hoc Bonferroni analysis indicated that both D1 and D2 postures demonstrated significantly larger P2 mean amplitudes than D3 did. None of the rest results revealed any interaction effect or main effects of posture or group.