Coherence and phase measures of the cross-frequency coupling of different frequency bands to θ phase frequency analyzed at a RAD electrode
| Low γ (30–57 Hz) | High γ (63–100 Hz) | Low ripples (100–250 Hz) | High ripples (250–400 Hz) | |
|---|---|---|---|---|
| Peak log power | –1.13 ± 0.06 | –2.18 ± 0.04 | –2.97 ± 0.05 | –4.00 ± 0.10 |
| Phase (RAD θ) | –80.1 ± 12.7° | –53.5 ± 23.8° | –58.2 ± 20.7° | –73.0 ± 21.6° |
| z-coherence | 0.14 ± 0.02 | 0.069 ± 0.016 | 0.086 ± 0.019 | 0.057 ± 0.012 |
| Number | 17 | 17 | 19 | 16 |
For each frequency band, a z-transform coherence (z-coherence) peak of >0.005 at a θ (2.9–6 Hz) frequency was required for inclusion. The mean peak theta frequency of the unfiltered signal (n = 19 rats) was 3.61 ± 0.10 Hz, with power of 0.46 ± 0.06 log units; zero log power is 1 mV2/Hz. Phase was analyzed using the RAD θ as reference.