Neural Avalanche

A neuronal avalanche is a cascade of bursts of activity in neuronal networks. This means that, after a period of not spiking a lot, a group of neurons spike repeatedly during a certain time frame, after which they collectively mostly stop firing.

Avalanche Duration
In order to determine the length of an avalanche first a threshold value is set. This value is set at 50% of the median spike activity. Then an avalanche starts when the overal network activity, over a certain time step, crosses the threshold. The avalanche ends when the network activity drops below this threshold.

Avalanche Size
The size of the avalanche is simply determined by the number of neurons that are active during the duration of the avalanche. For Self-Organized Criticality, the distribution of the avalanche size should follow a Power Law.