On the critical signatures of neural activity.

The critical brain hypothesis has emerged as an attractive framework to understand the functional implications of the variability in brain activity. However, the mechanisms behind the observed emergent collective neural patterns remain unclear. Here we propose a modeling framework to reconcile apparent contrasting results. We show that the presence of scale-free neuronal avalanches and the associated crackling-noise relation can be explained by the presence of an extrinsic, stochastic-induced mutual information in the system, whereas the intrinsic spatial correlation structure shows the typical features of systems close to their critical point. We test our results on data obtained from the rat's cortex through state-of-the-art multi-array probes.