No respiration-locked high-gamma modulation was detected in 20 HUP SEEG patients

We tested whether 70–150 Hz amplitude in human stereoelectroencephalography (SEEG) bipolar pairs changed with breathing phase at rest. Because OpenNeuro SEEG datasets lacked a respiration channel, we derived breathing phase from ECG R-peak amplitude (ECG-derived respiration, EDR), with respiratory sinus arrhythmia (RSA) from RR intervals as a secondary estimate. We analyzed 300-s interictal clips from 20 patients and 472 bipolar pairs in OpenNeuro ds004100. For each pair, we compared the modulation index of the QRS-masked high-gamma envelope and EDR phase with 500 circular-shift nulls. The mean fraction of significant pairs was 0.041 (95% bootstrap CI 0.021–0.063), not above the 0.05 false-positive rate (sign-flip p=0.41; Wilcoxon p=0.33). Mean pair z was 0.068 (95% CI −0.046–0.182; p=0.26). With RSA phase, the fraction was 0.088 (p=0.029; Holm p=0.058), nominal but not significant after correction. Raw 0.1–0.5 Hz SEEG was coherent with EDR in 12.5% of pairs (p=0.0028; Holm p=0.0084), consistent with a slow respiratory component that may be mechanical or volume-conducted. No patient had at least five significant pairs for the planned preferred-phase Rayleigh test. In a non-preregistered sensitivity analysis of 10 patients whose EDR and RSA spectral peaks agreed within 0.05 Hz, the primary fraction was 0.033 (sign-flip p=0.28). These data do not show respiration-phase locking of high-gamma amplitude in the sampled contacts. Limitations include ECG-proxy phase error, 300-s recordings (about 50–60 breaths), only the first 32 depth channels in alphabetical order, no anatomical labels, and a 20-of-38 patient sample from one center (HUP).

stereoelectroencephalography · respiration · high-gamma · ECG-derived respiration · respiratory sinus arrhythmia · OpenNeuro · signal coherence