Table 3. Overall ANOVA time effects (df = 4,66 or 2,44) for changes in physiological parameters across Still-Face Tests and paired t-tests (df = 15 or 22) testing changes from Play to Still-Face episodes 1 and 2.

	Overall ANOVA effect			P vs. SF1		P vs. SF2
	F	p	ηp2	T	p	t	p
Test 1 (n = 23)
RSA (mL)	1.69	.197	.071	2.75	.012
logRSA/VTc (log ms/mL)	13.43	.001	.379	4.99	.001
TTOT (s)	4.54	.019	.171	2.56	.018
VT (mL)	8.53	.001	.279	4.02	.001
HR (b/min)	16.16	.001	.423	7.04	.001
Test 1 and 2 (n = 16)†
RSA (mL)	4.36	.004	.225	3.36	.008	3.75	.004
logRSA/VTc (log ms/mL)	8.23	.001	.354	4.74	.001	4.51	.001
TTOT (s)	12.50	.001	.454	3.13	.014	7.33	.001
VT (mL)	7.09	.001	.321	3.30	.010	5.46	.001
HR (b/min)	7.74	.001	.340	4.95	.001	4.83	.001

Note: P = Play episode; SF1 = Still-Face episode 1; SF2 = Still-Face episode 2; T_TOT = total respiratory cycle time; V_T = tidal volume; RSA = respiratory sinus arrhythmia; logRSA/V_Tc = logarithm of RSA normalized by V_T (logarithm(RSA/V_T)+1), adjusted for T_TOT; HR = heart rate.

^† p-level of both t-tests for each index are Bonferroni-adjusted in this subgroup.