Neocortical activity is stimulus- and scale-invariant
Fig 4
Average avalanche size scales with duration as predicted for a network operating near criticality.
(A-C) For each avalanche (solid purple dots) the size is plotted (log-log scale) vs the duration for the three stimulus conditions (mouse #3). For each avalanche duration the average avalanche size (cyan dots) is plotted. The linear relationship on logarithmic axes reveals a power law relationship < S > ~ Dβ between average avalanche size and duration as predicted by criticality theory. The fitted exponent β is derived from the linear regression line (yellow dashes). The predicted line (red) is derived from the predicted exponent β = (α − 1)/(τ − 1). Solid purple dots were included in the exponent estimation, open circles were not (see Materials and methods). (D) The summary plot for all mice shows that the fitted exponent β largely matches the predicted exponent β = (α − 1)/(τ − 1) for all mice and stimulus conditions. This is despite the fact that different values were found for size exponents τ and duration exponents α for different mice and stimulus conditions.