Table 2.

Statistical evaluation of the effect of the preprocessing procedures for healthy controls.

Analysis method	Parameter	Main effect (Friedman test)		Post-hoc (Wilcoxon signed ranks test)
				P1–P2	P2–P3	P3–P4	P4–P5
		χ2	p	p	p	P	p
Independent component analysis	Qualitative	8	1	–	–	–	–
	PCC: z-score	22	0.007	1	1	0.004	0.001
	MPFC: z-score	31	0.0001	0.3	0.03	0.005	0.1
	LPR: z-score	17	0.07	–	–	–	–
	LPL: z-score	23	0.006	1	0.6	0.0003	0.02
	Extra-DMN: %	39	<0.0001	0.6	0.02	0.004	0.1
Seed-based analysis	MPFC: z-score	71	<0.0001	0.003	0.0002	1	0.3
	LPR: z-score	73	<0.0001	0.8	0.0005	1	1
	LPL: z-score	65	<0.0001	1	0.0005	1	1
	Extra-DMN: %	120	<0.0001	<0.0001	<0.0001	0.0001	0.0001
Linear regression	LPL-LPR: r	100	<0.0001	0.002	<0.0001	0.03	0.03
	PCCL-LPL: r	112	<0.0001	<0.0001	<0.0001	0.2	0.6
	PCCR-LPR: r	104	<0.0001	0.0005	<0.0001	1	1
	PCCL-MPFCL: r	108	<0.0001	<0.0001	<0.0001	0.2	0.01
	PCCR-MPFCR: r	110	<0.0001	<0.0001	<0.0001	0.08	0.005

As described in-text, Friedman tests followed, where appropriate, by Wilcoxon post-hocs were performed. All p-values are reported following Bonferroni-Holm correction. PCC, posterior cingulate and precuneus; LP, lateral parietal cortex; MPFC, anterior cingulate and medial prefrontal cortex. Subscripts “L” or “R” stand for left or right hemisphere. “Extra-DMN” refers to the proportion of activated voxels outside the expected DMN localization. The effect of preprocessing “grade” was significant for most parameters, with the greatest overall differences being observed between P1–P2 and P2–P3, corresponding to the addition of band-pass filtering and removal of co-variance with the movement vectors and global brain parenchyma signal. See text for details.