With new multichannel recording technologies, traveling waves of neural activity have recently been discovered in multiple sensory, motor, and cognitive regions of cortex. These waves can be spontaneously generated or evoked by external stimuli.
They travel along brain networks at single-region (mesoscopic) and whole-brain (macroscopic) scales and transiently modulate neuronal excitability as they propagate through local circuits. Their overall role in neural computation, however, remains poorly understood.
In recent work, we have introduced new methods for detection and quantification of traveling waves in multichannel recordings. At the mesoscopic scale, these methods have revealed that small visual stimuli consistently evoke outward traveling waves in primary visual cortex of the awake monkey (Muller et al., Nature Communications 5, 2014). At the macroscopic scale, the 11-15 Hz sleep "spindle", a brain oscillation causally implicated in consolidation of long-term memory, is consistently organized as a rotating wave traveling in a preferred direction (Muller et al., eLife 5, 2016). These results indicate that traveling waves play a role in organizing neural activity during multiple behavioral states. In upcoming work, we aim to address the network-level mechanisms generating traveling waves and complex spatiotemporal patterns, under the general aim of understanding their role in neural computation.