restingstate

Resting-state refers to brain activity observed when a person is not engaged in a specific task. In neuroscience and neuroimaging, resting-state functional connectivity studies measure spontaneous fluctuations in the BOLD signal to identify networks that appear to be functionally connected even in the absence of external stimuli.

Resting-state data are usually collected while participants lie still with eyes open or closed for several minutes. Preprocessing addresses motion and physiological noise. The approach enables mapping of intrinsic connectivity networks that underlie the brain’s baseline organization and its readiness to respond to tasks.

The field traces its origins to early findings by Biswal in the mid-1990s showing co-activation of distant motor regions during rest. The default mode network (DMN) is a prominent resting-state network; other networks include the frontoparietal control network, the salience network, sensorimotor networks, and visual networks. These networks show characteristic patterns of correlated activity that persist across many individuals.

Analysis methods include seed-based correlation, independent component analysis (ICA), and graph theory metrics to assess network topology. Measures focus on functional connectivity and network integrity, often exploring how activity in one region relates to activity in others.

Applications of resting-state research include mapping healthy brain organization, studying aging, and examining a range of neurological and psychiatric conditions where resting-state connectivity is altered, such as Alzheimer’s disease, autism spectrum disorders, and schizophrenia. Resting-state metrics can serve as potential biomarkers or targets for intervention, though findings vary across studies.

Limitations include sensitivity to head motion and physiological noise, ambiguity about whether functional connectivity reflects direct communication or common drivers, and challenges in standardization across scanners and protocols. Researchers emphasize cautious interpretation and replication to establish robust conclusions.