Spatiotemporal hierarchy of the brain’s complex dynamical organization spans multiple scales. The brain’s cognitive hierarchy includes five or more layers across at least 12 orders of magnitude, from large (nearly brain-wide, ~10 cm), relatively slow (10{}^2 Hz) processes based on neuronal membranes and synaptic network processes, downward and inward to increasingly smaller and faster molecular scales inside neurons, including the kilohertz (10{}^3) to petahertz (10{}^{15}) dynamics of cytoskeletal filaments, mitochondrial reticula, and their constituents at nanometer and sub-nanometer length scales. Adapted from [3].