Fig. 5: LFP discharge sequences exhibit strong directionality.
From: Focal seizures induce spatiotemporally organized spiking activity in the human cortex
a The timing of peak multi-unit spiking activity (MUA; top) and local field potential discharges (LFP; bottom) was mapped onto the spatial layout of the MEA during the same four example seizure bursts (blue: early; yellow: late). We fit a plane to the spatial organization of each spiking sequence, generating a measure of goodness of fit (R2, indicated by the length of the black arrow) and a direction (indicated by the direction of the black arrow). b Distribution of R2 values for all MUA spiking sequences (dark blue, mean R2 = 0.12 ± 0.09) and sequences of LFP discharges (maroon, mean R2 = 0.30 ± 0.21) during all seizure bursts in the same example seizure histogram, compared to null bursts (gray), created by scrambling the order of active spiking electrodes in the MUA sequences. c Average R2 over all seizure bursts for LFP discharges (mean 0.47 ± 0.13), MUA spiking sequences (mean 0.15 ± 0.05), and null bursts in every participant and array. Each dot represents a single participant and array. Average R2 was significantly greater for LFP discharges compared to MUA spiking sequences (two-tailed p < 0.001, repeated measures ANOVA; Holm–Bonferroni correction for multiple comparisons) and compared to null (p < 0.001). Average R2 was also significantly greater for MUA spiking sequences compared to null (p = 0.045).
