Figure 8.

Distributions of ripple characteristics across the cortex and hippocampus in NREM and waking. A-F, Cortical maps with hippocampal map insets of channel coverage (A) as well as NREM and waking mean ripple densities (B), peak 70-100 Hz analytic amplitudes (C), oscillation frequencies (D), durations (E), and changes in mean >200 Hz analytic amplitude during ripples compared with baseline (−2 to −1 s) (F) (SEEG Patients S1-S17; N = 273 channels). Left and right hemisphere channels were mapped onto a left hemisphere template. The parcellation scheme (specified in Table 2) is low resolution, and more extensive sampling may detect more spatially differentiated response characteristics. Values for each cortical region are reported in Table 3. G, H, Average cortical ripple density (G) and amplitude (H) by channel were significantly correlated with cortical parcel myelination index (i.e., lower densities and amplitudes in association compared with primary areas) (Rosen and Halgren, 2021) during NREM and waking (linear mixed-effects models with patient as random effect, FDR-corrected p values). Colors represent individual patients. I, Same as in G, H, but with change in mean >200 Hz amplitude z scores, for which there was a significant correlation during NREM but not waking.