BIO In the literature: contested

Is the brain poised near a critical point?

In plain words

Power-law statistics in brain activity suggest that neural networks operate at a phase transition. Other explanations, such as shared slowly varying inputs, can produce the same statistics without any tuning.

Precise statement

For cortical networks in vivo, determine whether collective activity is at or near a continuous phase transition (avalanche criticality at an absorbing-to-active boundary, or an edge-of-instability point), as opposed to a non-critical state producing power laws by other means (latent common inputs, subsampling, neutral dynamics), and whether the distance to criticality is regulated by homeostasis. An answer states criteria such as finite-size scaling under an independently varied control parameter.

What would settle it

Recordings in which a physiological control parameter is varied and activity shows finite-size scaling and divergent susceptibility at a specific value, excluding latent-variable explanations.

Status in the literature

Unverified note

Analyses in 2023 to 2026 report near-critical scaling in mouse and human recordings, while latent-variable models reproduce the same signatures without tuning; no consensus as of 2026.