Illustrated representation of the decomposition process of sDL. A matrix representing the complete volume of v voxel signals acquired from a scan of time t is arranged into a signal matrix . Through sDL, the matrix is decomposed into a dictionary matrix and , such that approximates . Dictionary contains activity for n number of atoms, or detected RSNs, whereas contains representations of the detect RSN maps that can be mapped back to a brain volume. BOLD, blood-oxygenation-level dependent; fMRI, functional magnetic resonance imaging; RSNs, resting-state networks; sDL, sparse dictionary learning.