Figure 1.

Ripple detection and event rejection. A, Broadband LFP single sweeps show events that exceeded amplitude thresholds and were accepted for or rejected from the analyses. Traces represent an example accepted ripple, with black arrows indicating multiple 70-100 Hz oscillation cycles, a rejected artifact, a rejected event with a single dominant cycle, and a rejected possible IIS. Putative ripples within ±500 ms of possible IIS detected on the same channel, as well as putative ripples coinciding with the sharp component of possible IIS on any cortical or hippocampal channel were rejected. B, Mean ± SD NREM ripple oscillation frequency (red line) across channels (N = 273; black lines) from all SEEG patients (S1-S17) is highly similar when using either a 70-100 Hz bandpass (mean ± SD = 89.1 ± 0.8 Hz) or a 65-120 Hz bandpass (92.7 ± 2.2 Hz). C, Average power spectral density of unfiltered, notched (60 Hz and harmonics), notched and 70-100 Hz bandpassed, as well as notched and 65-120 Hz bandpassed (N = 1000 randomly selected 27-s-long epochs over 450 min of recording from Patient S2). Dashed black lines indicate 70-100 Hz bandpass used for the main analyses in this study. Dashed red line indicates 90 Hz, the approximate average ripple frequency across states, structures, and filter settings.