Table 2A. The effect of preprocessing steps on coherence function of BOLD signals within regions of interest.

	Before	Low pass		Global		CSF		White matter		All
Regions of interest (ROIs)	Mean±s.d.	Mean±s.d.	P-value	Mean±s.d.	P-value	Mean±s.d.	P-value	Mean±s.d.	P-value	Mean±s.d.	P-value
Global↔R-ICC	0.70±0.15	0.69±0.14	0.146	0.30±0.07	<0.001	0.60±0.11	0.006	0.40±0.10	<0.001	0.29±0.06	<0.001
Global↔R-Hip	0.64±0.19	0.63±0.18	0.001	0.33±0.09	<0.001	0.56±0.15	0.027	0.36±0.10	<0.001	0.31±0.09	<0.001
Global↔R-LOC	0.68±0.16	0.66±0.17	0.034	0.41±0.14	<0.001	0.63±0.14	0.017	0.43±0.11	<0.001	0.38±0.14	<0.001
Global↔L-LOC	0.69±0.16	0.67±0.15	0.044	0.42±0.15	<0.001	0.66±0.14	0.030	0.47±0.12	<0.001	0.41±0.13	<0.001
R-ICC↔L-ICC	0.92±0.05	0.93±0.05	0.412	0.83±0.09	0.004	0.91±0.04	0.102	0.88±0.06	0.010	0.83±0.09	0.004
R-Hip↔L-Hip	0.82±0.07	0.82±0.07	0.534	0.62±0.12	0.001	0.79±0.06	0.207	0.70±0.10	0.009	0.65±0.10	0.001
R-LOC↔L-LOC	0.85±0.08	0.85±0.08	0.516	0.73±0.09	<0.001	0.84±0.08	0.038	0.74±0.10	<0.001	0.72±0.08	<0.001
R-Hip↔R-ICC	0.62±0.16	0.62±0.15	0.693	0.37±0.10	0.001	0.57±0.10	0.080	0.45±0.12	0.003	0.37±0.10	<0.001
R-Hip↔R-LOC	0.50±0.19	0.51±0.19	0.923	0.30±0.07	0.003	0.45±0.17	0.022	0.32±0.08	0.004	0.30±0.09	0.006
R-Hip↔L-LOC	0.49±0.19	0.49±0.19	0.931	0.30±0.07	0.005	0.44±0.17	0.042	0.31±0.09	0.009	0.28±0.08	0.003
R-ICC↔L-LOC	0.47±0.18	0.48±0.18	0.104	0.32±0.08	0.027	0.41±0.14	0.013	0.28±0.07	0.002	0.31±0.05	0.019
R-ICC↔R-LOC	0.47±0.19	0.48±0.18	0.105	0.32±0.09	0.037	0.42±0.14	0.032	0.27±0.08	0.002	0.32±0.08	0.032

BOLD, blood oxgen level dependent; CSF, cerebrospinal fluid; ICC, isthums of cingulate cortex; Hip, hippocampus; LOC, lateral occipital cortex; R, right side; L, left side. Bold represents P<0.05 after Bonferroni correction. Values are mean±standard deviation. P-values represent the results of paired t-test compared with before preprocessing. The effects of each preprocessing step as well as all of the steps combined are presented. Coherence function was derived from 0.016 to 0.078 Hz.