Statistical Methods

The above properties were computed based on the individual level. We examined whether there were altered topological properties in functional brain networks in FD patients using two-sample random permutation tests as follows. We considered a significant change in FD patients for each property using the following approach. First, we calculated the difference between FD patients and the HC group for one property of the brain networks using a two-sample t test method. Next, the property values in the patient group and control group were randomly permutated 1000 times and the difference was re-computed after each permutation. Then, 1000 P-values could form a null distribution. If the real difference before permutation reached the level 0.05 of the null distribution, the result was considered to be significant at P < 0.05 after the permutation test. In addition, the correlation analysis was conducted using the Pearson correlation.