Coherence Potentials: Loss-Less, All-or-None Network Events in the Cortex
Figure 3
Correlated waveforms are similar in amplitude.
(A) Schematic of amplitude comparison where the peak amplitude within the time-aligned window at each site was normalized by the peak amplitude of the trigger nLFP (elecamp/nLFPtrigamp). Comparison of time-aligned random segments was used as a control (red). (B) Distributions of log-normalized values as in (A) for correlated waveforms with peaks ≤−4 SD from the M1left array in monkey A distribute narrowly around 0 (i.e., log 1). Inclusion of waveforms at all sites irrespective of correlation broadens the original distribution towards ratios <1. The sharp peak at 0 is absent in random segment comparisons. (C) Fraction of sites with peak amplitude within ±50% of the nLFP trigger amplitude (shaded area in B) increased non-linearly as a function of trigger amplitude and was significantly greater for correlated waveforms alone (see Figure S4 for monkey B and cultures).