Beta-amplitude effects cannot be explained by differences in initial amplitude or phase stability. Beta-amplitude effects cannot be explained by differences in initial amplitude or phase stability. A, Beta amplitude (normalized to the median) at the time of the first pulse during epochs of consecutive stimuli did not differ between amplifying or suppressing phases (1 Pulse Epochs: p = 0.879; 2 Pulse Epochs: p = 0.742; 3 Pulse Epochs: p = 0.742; 4 Pulse Epochs: p = 0.742; 5 Pulse Epochs: p = 0.828; Wilcoxon rank sum test, FDR-corrected, 5 comparisons). B, Normalized histogram of cycle lengths over entire epochs of three consecutive pulses at the suppressing or amplifying phase for an example subject. C, Across eight patients there was no significant difference in the phase stability of the beta signal over epochs of three consecutive suppressing or amplifying stimuli as determined from entropy measures derived from cycle length histograms (W = 73, p = 0.645, Wilcoxon rank sum test). D, Normalized histogram of cycle lengths for the initial cycle of epochs of three consecutive suppressing or amplifying stimuli for an example patient. E, Across eight patients, there was no significant difference in the phase stability of the initial cycle of three consecutive suppressing or amplifying pulse epochs (W = 69, p = 0.959, Wilcoxon rank sum test). Abbey B. Holt et al. J. Neurosci. 2019;39:1119-1134 ©2019 by Society for Neuroscience