Robust and stable small-world topology of brain intrinsic organization during pre- and post-task resting states

Brain functional network studies have demonstrated the small-world topology as the nature of large-scale spontaneous brain activity. Studies have also revealed that the temporal coherence of spontaneous activity could be reshaped during task-dependent (or post-task) resting states within local spatial patterns such as task-related and the default-mode networks. However, to our best knowledge, it is still a lack of rigorous investigations that whether the small-world topology of spontaneous intrinsic organization remains robust and stable during different resting states. To address the problem, we recorded blood oxygen level-dependent (BOLD) signals from two rests (namely, pre- and post-task resting states) before and after a simple semantic-matching task, and investigated the preceding task influences on the topology of the large-scale spontaneous intrinsic organization during the post-task resting state. The major findings are that the small-world configuration of spontaneous intrinsic organization remains robust and stable during resting states regardless of preceding task influences.