Sampling effects and measurement overlap can bias the inference of neuronal avalanches
Fig 7
In vivo avalanche-size distributions p(S) from spikes depend on time-bin size Δt.
In vivo results from spikes are reproduced by sub-sampled simulations of subcritical to reverberating dynamics. Neither spike experiments nor sub-sampled simulations show the cut-off that is characteristic under coarse-sampling. A: Experimental in vivo results (spikes, awake monkey) from an array of 16 electrodes, adapted from [24]. The pronounced decay and the dependence on bin size indicate subcritical dynamics. B: Experimental in vitro results (spikes, culture DIV 34) from an array with 59 electrodes, adapted from [44]. Avalanche-size distributions are largely independent of time-bin size and resemble a power law over four orders of magnitude. In combination, this indicates a separation of timescales and critical dynamics (or even super critical dynamics [45]). B, Inset: Log-Lin plot of fitted α, fit range s/N ≤ 5. C–F: Simulation for sub-sampling, analogous to Fig 6. Subcritical dynamics do not produce power-law distributions and are clearly distinguishable from critical dynamics. F: Only the (close-to) critical simulation produces power-law distributions. F, Inset: Log-Log plot of fitted α, fit range S ≤ 50. In contrast to the in vitro culture (in B), the simulation does not feature a separation of time scales (due to external drive and stationary activity), and therefore the slope shows a systematic bin-size dependence here.