Figure 1: Example traveling waves in the human neocortex.

Panels A–G show data from an 8.3-Hz traveling wave in Patient 1. (A) Top panel, raw signals for 4 s of one trial from three selected electrodes. The selected electrodes are ordered from anterior (top) to posterior (bottom). Middle panel, a 500-ms zoomed version of the signals from the top panel. Bottom panel, signals filtered at 6–10 Hz. (B) Relative phase of this traveling wave on this trial across the 3×8 electrode grid. Color indicates the relative phase on each electrode. Arrow indicates direction of wave propagation. Inset shows the normalized power spectrum for each electrode, demonstrating that all the electrodes exhibit narrowband 8.3-Hz oscillations. (C) Illustration of the circular–linear model for quantifying single-trial spatial phase gradients and traveling waves. Black dots indicate the relative phase for each electrode in this cluster on this trial; colored surface indicates the fitted phase plane from the circular–linear model; black lines indicate residuals. (D) The topography of this traveling wave’s phase at four timepoints during this trial. (E) Illustration of the average traveling wave on this cluster across trials. Each electrode’s time-averaged waveform is computed as the average signal relative to oscillation troughs triggered from electrode 5. (F) Analysis of phase-gradient directionality (PGD) for the traveling waves on this cluster. Black line indicates the median PGD for this cluster, computed across trials. Gray bars indicate the distribution of median PGD values expected by chance for this cluster, estimated from shuffled data. (G) Histogram indicating the distribution across trials of propagation directions for the traveling waves on this cluster. (H) Example 5.9-Hz traveling wave from Patient 3.(I) Example 7.9-Hz traveling wave from Patient 63. (J) Example 8.8-Hz traveling wave from Patient 77.