Salience network functional connectivity is spatially heterogeneous across sensorimotor cortex in healthy humans.

The salience network is responsive during a range of conditions requiring immediate behavioral responses, including pain processing. Resting-state functional connectivity of the salience network to the sensorimotor cortex is altered in chronic pain. However, little is understood about their fundamental communication in the absence of pain. In this study, we mapped salience network resting-state functional connectivity across sensorimotor cortex in healthy individuals. Using electromyography and task-based functional magnetic resonance imaging (fMRI), we first localized distinct regions-of-interest across sensorimotor cortex in medial (gluteal), intermediate (shoulder), and lateral (hand) areas. We then used resting-state fMRI for two cohorts (primary and replication) of healthy individuals from public repositories to map salience network resting-state functional connectivity across sensorimotor cortex. Both the primary and replication cohorts exhibited significant heterogeneity in salience network resting-state functional connectivity across the sensorimotor regions-of-interest. Using a cortical flatmap to visualize the entire sensorimotor surface, we observed similar heterogeneity in both cohorts. In general, the somatotopic representation of proximal body regions (trunk/face) had higher salience network resting-state functional connectivity compared to distal body regions (upper/lower limbs). We conclude that sensorimotor cortex is spatially heterogeneous in its interaction with the salience network in healthy individuals.