. Author manuscript; available in PMC: 2012 Jul 1.

Published in final edited form as: Magn Reson Imaging. 2011 May 14;29(6):819–826. doi: 10.1016/j.mri.2011.02.017

Table 1.

Whole brain all subject averages ± across-subject standard deviation for measures of the impact of physiologic noise correction.

	Correction Applied	σ (%)	Max R²_a	Mean R²_a	Activation (%)
1.5 T	No correction	0.282 = 0.055	0.4067 ± 0.0765	0.0360 ± 0.0047	2.79 ± 1.60
	RB only	0.278 = 0.055	0.4183 ± 0.0912	0.0564 ± 0.0040	2.60 ± 1.55
	PPG only	0.278 = 0.055	0.4059 ± 0.0666	0.0568 ± 0.0048	2.78 ± 1.76
	RETROICOR	0.259 = 0.054	0.5860 ± 0.2103	0.1177 ± 0.0289	2.35 ± 1.40
	RETROICOR + ETCO₂	0.254 = 0.053	0.5706 ± 0.2244	0.1175 ± 0.0326	2.14 ± 3.03

3.0 T	No correction	0.366 = 0.114	0.4481 ± 0.0980	0.0572 ± 0.0246	7.66 ± 5.71
	RB only	0.359 = 0.113	0.4610 ± 0.0888	0.0783 ± 0.0247	7.91 ± 5.72
	PPG only	0.360 = 0.113	0.4622 ± 0.0788	0.0765 ± 0.0255	7.63 ± 5.71
	RETROICOR	0.328 – 0.104	0.7459 + 0.0872	0.1945 + 0.0531	6.97 + 4.88
	RETROICOR + ETCO₂	0.320 = 0.090	0.7522 ± 0.0718	0.2028 ± 0.0487	6.82 ± 5.00

Legend: σ (%) = temporal standard deviation of the preprocessed FMRI data timecourse as a percentage of the total MR signal amplitude. Max and mean R² _a are, respectively, the maximum and average adjusted coefficient of multiple determination. Activation (%) is the number of activated voxels expressed as a percentage of the total.