Traveling electrical waves in cortex: insights from phase dynamics and speculation on a computational role

The theory of coupled phase oscillators provides a framework to understand the emergent properties of networks of neuronal oscillators. When the archi tecture of the network is dominated by short-range connections, the pattern of electrical output is predicted to correspond to traveling plane and rot ating waves, in addition to synchronized output. We argue that this theory provides the foundation for understanding the traveling electrical waves th at are observed across olfactory, visual, and visuomotor areas of cortex in a variety of species. The waves are typically present during periods outsi de of stimulation, while synchronous activity typically dominates in the pr esence of a strong stimulus. We suggest that the continuum of phase shifts during epochs with traveling waves provides a means to scan the incoming se nsory stream for novel features. Experiments to test our theoretical approa ch are presented.