Table 2.

Effect Size and Tests of heterogeneity between experiments comparing MMN amplitude and MMN latency between ASD and TD groups.Results are computed for all experiments in the meta-analysis and experiments that counterbalanced standards and deviants. Positive SMD values correspond to the ASD group’s overall reduction in that metric, while negative values represent an increase.

	Test of Heterogeneity						Effect Size
Sample	Q	df	p value	T2	H	I2 [95% CI]	SMD [95% CI]	z-score	p value
Amplitude Measures: All	98.48	63	<0.01	0.09	1.25	36.0 [13–53]	0.071 [−0.06–0.20]	1.1	0.27
Amplitude Measures: Counterbalanced	24.07	23	0.40	0.01	1.02	4.4 [0–35]	0.15 [−0.02–0.32]	1.78	0.07
Amplitude Measures: Speech	11.27	10	0.34	0.02	1.06	11.2 [0–51]	0.01 [−0.25–0.27]	0.07	0.94
Amplitude Measures: Nonspeech	10.87	12	0.54	0.00	1.00	0.0 [0–52]	0.25 [0.03–0.46]	2.26	0.02
Latency Measures: All	154.32	49	<0.01	0.36	1.79	68.9 [58–77]	−0.02 [−0.22–0.19]	−0.14	0.89
Latency Measures: Counterbalanced	67.03	18	<0.01	0.47	1.93	22.9 [0–56]	0.16 [−0.20–0.53]	0.89	0.37