Figure 1. Global parameters of the brain functional networks for the heroin-dependent individuals (HDIs) and the normal controls (NCs) changing with the sparsity threshold.

The error bar represents the standard deviation of a parameter at a given sparsity across all subjects. The symbol (*) means that significant between-group difference in the given parameter was detected (p<0.05). Except for the sparsity range of 0.05≤sparsity≤0.09, no statistically significant between-group differences were detected for other values of sparsity. , clustering coefficient; , characteristic path length; , normalized clustering coefficient; , normalized shortest path length; , small-worldness; , global efficiency; , local efficiency.