Our brains might be functioning close to a tipping point, according to new research from Northwestern University. This “critical point” is a state of high complexity seen in materials when they smoothly transition from one phase to another, like a magnet losing its magnetism when heated.
Scientists analysed brain scans of humans, mice, and fruit flies, finding a similar critical point in all three species. This suggests the finding could be a fundamental principle across brains.
While the researchers don’t yet understand what specific phases the brain might be transitioning between, this discovery could be key to developing more complex brain models. These models could help us better understand how our brains work and the amazing things they can do.
“The human brain is one of the most complex systems known, and many properties of the details governing its structure are not yet understood,” said Northwestern’s Istvan Kovacs, the study’s senior author. “Several other researchers have studied brain criticality in terms of neuron dynamics. But we are looking at criticality at the structural level in order to ultimately understand how this underpins the complexity of brain dynamics. That has been a missing piece for how we think about the brain’s complexity. Unlike in a computer, where any software can run on the same hardware, in the brain, the dynamics and the hardware are strongly related.”
“The structure of the brain at the cellular level appears to be near a phase transition,” said Northwestern’s Helen Ansell, the paper’s first author. “An everyday example of this is when ice melts into water. It’s still water molecules, but they are undergoing a transition from solid to liquid. We certainly are not saying that the brain is nearing melting. In fact, we don’t have a way of knowing what two phases the brain could be transitioning between. Because if it were on either side of the critical point, it wouldn’t be a brain.”
The research was published on June 10 in Communications Physics, a journal published by Nature Portfolio.
According to the researchers, these discoveries may influence the creation of neural networks in computers as well as statistical models of the brain. Additionally, they add that they will carry out more research and examine many creatures to determine whether the state of criticality is more broadly applicable.
