Figure 4. Avalanche distributions differed with vigilance states and synaptic strength dE.

A. The avalanche size distribution f(s) for the neuronal avalanches was evaluated for each vigilance state separately. f(s) was similar for all vigilance states, however, it showed fewer large avalanches for REM sleep than for SWS (s2 and s3/s4). All f(s) were normalized such that f(s = 1): = 1. B Here, we showed the same results as in A, however, f(s) was plotted separately for each of the 10 recording nights to show that the differences in f(s) with vigilance states were present in each night. (Logarithmic binning to smooth the curves; the offset between the sets is two orders of magnitude.) C. The avalanche distribution for the subsampled SOC model was close to a power law for the critical state (black line). To deviate from the critical state, the synaptic strength dE was varied systematically by up to 0.6% (colored lines). Technically, for dE<1 the model is subcritcal and for dE>1 it is supercritical. With larger dE, f(s) showed an increased number of large avalanches. For the supercritical state (dE>1) a significant amount of avalanches was larger than 64, the number of sampling sites. D. The results for the fully sampled model look similar to the subsampled model, except that the cutoff is, as expected, at larger s.