Neurons on a 2D grid fire when input exceeds threshold, exciting neighbors. SOC self-tunes the network to criticality. Avalanche size distribution follows a power law P(s) ∝ s⁻¹·⁵.
Beggs & Plenz (2003) discovered neuronal avalanches in cortical tissue with P(s)∝s⁻¹·⁵ — the hallmark of criticality in the directed percolation universality class. SOC (Bak 1987): the system self-organizes to the critical point without fine-tuning, maximizing dynamic range and information transmission.