Table 1.
Cortical ripple coupling with cortical or hippocampal ripples: frequency and order
| Ripple | ripple | Significant modulation | Significant Sidedness | Cortical ripple leading |
|---|---|---|---|
| NREM | |||
| Cort-R | Cort-R | 98.6% (4,487/4,550) | 3.5% (157/4,487) | N/A |
| Hipp-R | Cort-R | 28.9% (133/461) | 31.6% (42/133) | 33.3% (14/42)* |
| Cort-R | Hipp-R | 29.3% (135/461) | 31.1% (42/135) | 33.3% (14/42)* |
| Hipp-SWR | Cort-R | 19.7% (91/461) | 45.1% (41/91) | 24.4% (10/41)* |
| Cort-R | Hipp-SWR | 20.6% (95/461) | 44.2% (42/95) | 21.4% (9/42)* |
| Hipp-SSR | Cort-R | 12.2% (56/461) | 17.9% (10/56) | 50.0% (5/10) |
| Cort-R | Hipp-SSR | 11.7% (54/461) | 22.2% (11/54) | 41.7% (5/12) |
| Waking | |||
| Cort-R | Cort-R | 98.4% (4,478/4,550) | 8.1% (364/4,478) | N/A |
| Hipp-R | Cort-R | 87.0% (401/461) | 22.4% (90/401) | 84.4% (76/90)* |
| Cort-R | Hipp-R | 87.4% (403/461) | 22.3% (90/403) | 84.4% (76/90)* |
Significant modulation: Proportion of channel pairs with a significant increase in the conditional probability of a ripple occurring in the first channel given that one occurred within ±500 ms in the second (e.g., Hipp-R | Cort-R refers to hippocampal ripples occurring within ±500 ms relative to cortical ripples at t = 0; one-sided randomization test, 200 shuffles, 25-ms nonoverlapping bins, three consecutive bins each with post-FDR P < 0.05 required for significance). During NREM, conditional probabilities are shown separately for those hippocampal ripples associated with sharpwaves (Hipp-SWR) and sleep spindles (Hipp-SSR) as well as all ripples (Hipp-R). Significant sidedness: Those with significant modulations that had significant sidedness preference around t = 0 (post-FDR P < 0.05, two-sided binomial test, expected = 0.5, −500 to −1 ms vs. 1 to 500 ms). Cortical ripple leading: Those with significant sidedness around 0 that had cortical ripples leading (according to counts within −500 to −1 ms vs. 1 to 500 ms). During NREM, Hipp-R and Hipp-SWR led Cort-R, and during waking, Cort-R led Hipp-R (*P < 0.05, two-sided binomial test, expected value = 0.5), resulting in a significant preference for cortical ripples to lead hippocampal ripples in waking vs. NREM (P < 0.00001, χ2 = 51.59, df = 1). See SI Appendix, Table 3 for results from individual patients. N/A, not applicable since both channels are cortical.