Traveling waves across scales: Different mechanisms but same canonical computation?

Non-stationary dynamical cortical states - neural activity changing on the topology of the cortex across time - and in particular traveling waves, is an emerging topic. In this article, we propose that similar spatio-temporal traveling wave patterns observed across cortical scales are underpinned by generative mechanisms that differ in nature, that we categorize as first- and second-order traveling waves. This original definition provides a unifying framework making testable predictions at both mechanistic and functional levels. While having diverse mechanistic origins, we propose that traveling waves across spatial and temporal scales subserve a canonical computation at the core of a variety of brain functions, thereby ordering neuronal processing to impose a computational syntax.