Fig. 2: Extracting spike waveform parameters.
a, The bottom of one shank and its recording sites. b, The average spike waveform for an example unit, in the 22 recording sites marked in black in a and in 12 adjacent sites (gray). c, The amplitude of the waveform as a function of distance to ‘max site’ for the example unit. Using an exponential decay fit (curve), we defined the distance d10 at which the amplitude drops to 10% of the maximum. Spatial decay is computed from the slope of the amplitude decrease over distance. d, The distribution of d10 for all units in two example recordings, showing the median (solid line) and the 95% confidence interval (dashed lines). e, The weighted-average waveform for the example unit in b and c, computed by giving larger weight to sites near the maximum site. The unit’s amplitude is taken from this weighted-average waveform. f, The centroid trajectory of the example waveform from 0.2 ms before the peak (bottom) to 0.5 ms after the peak (top), showing the average centroid (circle). The travel direction and distance are calculated at each time point.
