Planar, spiral, and concentric traveling waves distinguish behavioral states in human memory

A fundamental challenge in neuroscience is explaining how widespread brain regions flexibly interact to support behaviors. We hypothesize that traveling waves of oscillations are a key mechanism of neural coordination, such that they propagate across the cortex in distinctive spatial patterns that control how different regions interact. To test this hypothesis, we used direct brain recordings from humans performing multiple memory experiments and an analytical framework that flexibly measures the propagation patterns of traveling waves. We found that traveling waves propagated along the cortex in not only plane waves, but also spirals, sources and sinks, and more complex patterns. The propagation patterns of traveling waves correlated with novel aspects of behavior, with specific spatial patterns reflecting particular cortical processes and even individual remembered items. Our findings show that large-scale cortical patterns of traveling waves reveal a diverse range of spatial patterns in the brain that are relevant for neural decoding.