Table 1.

Demographics and ERP results of control and patient groups (SD in parentheses).^a

	Control	Patients	Statistics	Effect size (Cohen’s d)
	n = 120	n = 42
Age	26.63 (5.09)	25.82 (7.08)	0.424
Male gender (%)b	63 (52.5%)	21 (50%)	χ2 = 0.08, p = 0.78
Education (years)	15.62 (1.88)	14.00 (2.51)	<0.001**
Smoking PPD	0.03 (0.1)	0.15 (0.4)	0.035*
PANSS
Positive symptoms (P1 to P7)	—	17.0 (4.3)
Negative symptoms (N1 to N7)	—	14.1 (5.9)
General psychopathology (G1 to G16)	—	35.3 (8.6)
MMN Fz	−1.36 (0.81)	−1.05 (0.78)	0.047*	0.39
P50
S1 amplitude	2.44 (1.06)	2.53 (1.4)	0.679	0.07
S2 amplitude	1.09 (0.64)	1.45 (0.84)	0.008**	0.48
P50 ratio	0.51 (0.34)	0.63 (0.38)	0.075	0.33
P50 difference	1.35 (1.07)	1.08 (1.39)	0.239	0.22
N100
S1 amplitude	6.73 (3.27)	5.82 (2.95)	0.150	0.29
S2 amplitude	2 (1.31)	2.46 (1.3)	0.073	0.35
N100 ratio	0.36 (0.31)	0.51 (0.34)	0.017*	0.46
N100 difference	4.73 (3.35)	3.36 (2.62)	0.030*	0.46

UHR, ultra-high-risk group; FEP, first-episode psychosis group. ERP, event-related potential. MMN, mismatch negativity.

^aSome subjects failed to stay before the ERP session was terminated. The number of analyzable P50/N100 subjects was 20 UHR and 13 FEP. The number of analyzable MMN subjects was 18 UHR and 16 FEP.

^bChi-square tests.

^*p < 0.05.

^**p < 0.01.