Table 4.

Group mean and standard deviation (SD) mismatch negativity (MMN) amplitude values in microvolts for each deviant type at the six fronto-central electrode sites (F3, Fz, F4, C3, Cz, C4).

Group	Site	Duration-deviant		Frequency-deviant		Double-deviant		Intensity-deviant
		Mean	SD	Mean	SD	Mean	SD	Mean	SD
Healthy controls (N = 21)	F3	−2.52	1.03	−2.99	1.28	−3.57	1.62	−3.36	1.49
	Fz	−2.98	1.11	−3.13	1.23	−3.86	1.62	−3.63	1.69
	F4	−2.84	1.08	−3.07	1.37	−4.05	1.69	−3.71	1.79
	C3	−2.54	1.24	−2.56	1.21	−3.52	1.74	−3.00	1.46
	Cz	−2.66	1.23	−2.63	1.22	−3.43	1.69	−3.05	1.59
	C4	−2.53	1.00	−2.54	1.14	−3.55	1.65	−3.20	1.59
Early illness schizophrenia patients (N = 24)	F3	−1.96	0.98	−2.08	1.09	−3.04	1.17	−2.68	1.18
	Fz	−2.38	1.22	−2.33	1.02	−3.28	1.35	−2.92	1.13
	F4	−2.33	1.35	−2.33	0.89	−3.41	1.24	−2.90	1.02
	C3	−1.79	0.93	−1.82	1.17	−2.72	1.26	−2.30	1.22
	Cz	−2.25	1.12	−1.93	1.08	−2.69	1.39	−2.60	1.26
	C4	−2.15	0.88	−1.96	0.84	−2.83	1.09	−2.45	0.93