Table 6.

Statistical results for the effects of head shaking (phase effect) on the relative cumulative variance rCUM of PP_k for the four testing conditions based on rANOVA (black letters) or Friedmann tests (grey letters). For rANOVA results partial eta-square (η²) are reported as a as measure of the effect size, and 1−β for the observed power. Asterisks (*) indicate significant head-shaking effects on the relative variance of the movement component.

PPk	Trial		Overall rCUM
			F | χ2	DoF	p-Value	η 2	1 − β
PP1	Nodding head	eyes open	1.320	2, 30	0.282	0.081	0.263
		eyes closed	1.719	2, 30	0.196	0.103	0.332
	Tilting head	eyes open	0.625	2, 30	0.542	0.040	0.145
		eyes closed	0.274	2, 30	0.763	0.018	0.089
PP2	Nodding head	eyes open	3.917	2, 30	0.031 *	0.207	0.661
		eyes closed	0.032	2, 30	0.968	0.002	0.054
	Tilting head	eyes open	1.004	2, 30	0.378	0.063	0.208
		eyes closed	0.206	2, 30	0.815	0.014	0.079
PP3	Nodding head	eyes open	2.816	2, 30	0.076	0.158	0.551
		eyes closed	0.524	2, 30	0.597	0.034	0.128
	Tilting head	eyes open	0.765	2, 30	0.474	0.049	0.168
		eyes closed	0.178	2, 30	0.838	0.012	0.075
PP4	Nodding head	eyes open	2.822	2, 30	0.075	0.158	0.512
		eyes closed	0.500	2	0.779	-	-
	Tilting head	eyes open	0.966	2, 30	0.392	0.060	0.202
		eyes closed	0.141	2, 30	0.869	0.009	0.070
PP5	Nodding head	eyes open	2.823	2, 30	0.075	0.158	0.513
		eyes closed	1.625	2	0.444	-	-
	Tilting head	eyes open	0.876	2, 30	0.427	0.055	0.187
		eyes closed	2.625	2	0.269	-	-