Table 1.

Mean correlation coefficients (Fisher’s Z’) between SD 1 and absolute band power in the six HF bands ¹ (mean ± SD).

	Analysis 1: Sleep vs. Daytime 2		Analysis 2: Low vs. High Activity 3
	Sleep	Daytime	Low Activity	High Activity
Z’(ln(SD1)∗ln(HF1))
toddlers	2.06 ± 0.48	1.59 ± 0.32	1.51 ± 0.37	1.23 ± 0.21
adults	2.15 ± 0.38	1.97 ± 0.28	1.84 ± 0.38	1.61 ± 0.35
Z’(ln(SD1)∗ln(HF2))
toddlers	2.47 ± 0.39	2.05 ± 0.36	2.04 ± 0.41	1.61 ± 0.29
adults	2.28 ± 0.38	2.23 ± 0.29	2.05 ± 0.36	1.92 ± 0.33
Z’(ln(SD1)∗ln(HF3))
toddlers	2.30 ± 0.45	2.26 ± 0.35	2.16 ± 0.40	1.92 ± 0.26
adults	1.40 ± 0.56	2.27 ± 0.35	1.92 ± 0.36	2.05 ± 0.35
Z’(ln(SD1)∗ln(HF4))
toddlers	2.51 ± 0.38	2.13 ± 0.36	2.11 ± 0.40	1.71 ± 0.28
adults	2.28 ± 0.38	2.27 ± 0.30	2.06 ± 0.37	1.99 ± 0.31
Z’(ln(SD1)∗ln(HF5))
toddlers	1.99 ± 0.48	1.63 ± 0.36	1.51 ± 0.43	1.29 ± 0.23
adults	2.13 ± 0.37	1.90 ± 0.30	1.63 ± 0.33	1.05 ± 0.31
Z’(ln(SD1)∗ln(HF6))
toddlers	2.35 ± 0.36	2.14 ± 0.35	2.05 ± 0.41	1.78 ± 0.26
adults	2.26 ± 0.37	2.10 ± 0.32	1.78 ± 0.33	1.76 ± 0.31

¹ Correlations were computed for each participant and Fisher’s Z’ was transformed to enable inferential statistical analysis (see Section 2.3.4). ² Significant three-way interaction frequency band × time of day × age group (F(5,465) = 41.7, p < 0.001). ³ Significant three-way interaction frequency band × activity level × age group (F(5,465) = 15.2, p < 0.001).