Extended Data Fig. 9: Spatial waveform measures.
From: Large-scale neural recordings with single neuron resolution using Neuropixels probes in human cortex
a. Spatial spread examples of individual units (averaged across all waveforms attributed to a given unit) across the left and right columns of the Neuropixels probe. Voltage indicated by the greyscale color scheme. Bottom plot: diagram (arrows) demonstrating the spatial mapping calculations, including spatial spread, velocity above (yellow arrow), and velocity below (cyan arrow) the center point (channel with the largest waveform). (Measures shown in Extended Data Fig. 4). b. The spatial spread, depth, velocity above, and velocity below the center point (channel with the largest waveform) violin plots are shown for the different waveform types. * indicate significant differences between all putative cell or waveform types, Kruskal-Wallis multiple comparison test, p < 0.001 with post hoc Tukey-Kramer test. Grey letters a-c indicate statistically separable groups. Left: single channel classifications. Middle: multichannel classification based on the principal components and k-means clustering across patients. Right: multichannel classification based on the WaveMAP clustering across patients.
