Researchers find major clue to consciousness

A new line of research ties consciousness to a brain state called “criticality”—a balance point between rigid order and runaway chaos—arguing that this regime enables fast, accurate decisions despite slow neural signaling. The core claim is that when the brain operates near the edge of chaos, it develops long-range correlations across brain regions. Those correlations let distant parts of the brain coordinate quickly, helping explain how humans can predict and act in fractions of a second without needing the massive computational throughput and power draw of conventional computers.

The argument starts with a mismatch: neurons communicate slowly, with signals taking roughly 10–20 milliseconds to travel between neurons, yet people perform rapid, complex tasks like catching a ball mid-flight. In that scenario, the brain must estimate trajectories and trigger coordinated muscle responses almost instantly. Since modern computers can execute hundreds of billions to trillions of operations per second, the question becomes how the brain achieves comparable performance with far less raw speed.

The proposed answer borrows from physics. In complex systems, there is a “critical range” (often described as the edge of chaos) where behavior shifts from orderly to chaotic. In that transition regime, emergent features and complexity can arise. The transcript uses an analogy: if immigration is completely forbidden, the system is perfectly ordered but rigid; if immigration is completely unrestricted, the system becomes fully chaotic; the real world sits in between, where partial freedom produces richer, more interconnected patterns. In physics, criticality is treated as a rigorous concept, with long-range correlations as a hallmark. Examples include Bose–Einstein condensation, where long-range correlations allow a quantum state to extend across the whole condensate, and critical behavior seen in systems like stock markets as they move from order toward chaos.

Applying this to the brain, the researchers propose that consciousness depends on the brain lingering near this critical transition. Long-range connections in a critical system would allow different brain areas to “talk” more effectively, supporting rapid decision-making and reducing the need for high power consumption. The transcript emphasizes the energy gap: supercomputers typically require at least megawatts, while the human brain runs on about 20 watts—roughly enough for a dim bulb.

To test the idea, the researchers build a model using mathematics from quantum mechanics and use it to quantify how critical a brain’s state is. They then analyze functional MRI scans from more than 1,000 people and report that the criticality measure can distinguish people who are awake from those who are sleeping. The finding is presented as evidence that criticality tracks aspects of consciousness, even if the quantum-mechanics language does not necessarily mean the brain is a literal quantum computer. The broader takeaway is that generating complex, conscious behavior may require a system with “chaos within it,” enabling the emergence of coordinated dynamics rather than purely deterministic order.