Is There Sufficient Evidence for Criticality in Cortical Systems?

Area of Science:

• Neuroscience
• Complex Systems

Background:

• The brain's information processing capabilities are hypothesized to be linked to operating at a critical point.
• Recent studies suggest criticality signatures are present across diverse neural systems, from cultures to awake brains.

Purpose of the Study:

• To critically evaluate the methodology used to identify criticality in neural systems.
• To investigate whether the observed criticality signatures are robust or artifacts of the analytical approach.

Main Methods:

• Analysis of statistical methods used in previous criticality studies.
• Replication of criticality assessment on data from two known non-critical systems.
• Comparison of results from non-critical systems with those reported for neural systems.

Main Results:

• Non-critical systems exhibited identical scaling and criticality signatures as reported for neural systems.
• The methodology used in prior studies appears insufficient to definitively establish criticality.
• A crucial control analysis, absent in previous work, highlights potential flaws.

Conclusions:

• The claim that the brain operates at criticality, based on current methods, is questionable.
• The observed criticality signatures may not be unique to critical systems.
• Developing more robust methods is essential to determine if the brain operates at criticality.