Table 2.

Results of likelihood-ratio tests to determine the best-fitting model by group and condition.

Condition	Group	Comparison	DF	F	P	The better fitting model	The best-fitting model
Speech	ASD	Linear and Quadratic	1	0.71	0.40	Linear	Cubic model
		Linear and Cubic	2	10.48	<0.001 ***	Cubic
		Cubic and Quartic	1	1.18	0.28	Cubic
	Non-ASD	Linear and Quadratic	1	1.26	0.26	Linear	Cubic model
		Linear and Cubic	2	26.00	<0.001 ***	Cubic
		Cubic and Quartic	1	0.71	0.40	Cubic
Complex tone	ASD	Linear and Quadratic	1	0.15	0.70	Linear	Quartic model
		Linear and Cubic	2	2.68	0.07	Linear
		Linear and Quartic	3	3.07	0.03 *	Quartic
	Non-ASD	Linear and Quadratic	1	2.20	0.14	Linear	Cubic model
		Linear and Cubic	2	10.43	<0.001 ***	Cubic
		Cubic and Quartic	1	2.30	0.13	Cubic

ASD: autism spectrum disorder.

^*p < 0.05; **p < 0.01; ***p < 0.001.