Figure 2. Seizures can be segmented into distinct stages based on LFPs or MUA.

All data on this figure are from P1, seizure 1. (A) Top trace: LFPs from a representative electrode. Heat map below: corresponding multitaper spectrogram (see Materials and Methods). Red box (solid lines): time period manually selected for segmentation, encompassing seizure onset (indicated by t = 0 s, based on visual inspection). Dashed red lines: results of a semi-automatic segmentation algorithm (see Materials and Methods) applied on LFPs, and dividing the seizure into different stages. (B) LFP-based distance matrix used by the segmentation algorithm to find transitions between different segments/stages. Each axis: time period within the red box in (A). The color of each point (t_i, t_j) represents the “distance”, or dissimilarity, between the multichannel LFPs recorded at the two times t_i and t_j, based on spectral features obtained from LFPs. Dashed red lines: limits of the different stages found by the algorithm, and also shown in (A). (C) Top trace: high-pass MUA from the same electrode as in (A). Heat map: MUA rate (in 1-s bins) over time (x-axis) and across electrodes (y-axis, ordered row-wise across the MEA). Red box: same as in (A). Dashed red lines: results of the segmentation algorithm applied to MUA data. Note the differences between the segmentations based on LFPs and MUA. (D) MUA-based distance matrix used by the segmentation algorithm. This panel is similar to (B) but with features derived from MUA instead of LFPs.