Study plots cosmic brains
Italian researchers have found some surprising links between the structure of the human brain and the structure of the universe.
An astrophysicist from the University of Bologna and a neurosurgeon from the University of Verona have compared the cosmic network of galaxies with the network of neurons in the cerebral cortex, and found some strikingly similar characteristics.
The new study, published in the journal Frontiers of Physics, sees astrophysicist Dr Franco Vazza and neurosurgeon Dr Alberto Feletti investigate two of the most enigmatic and complex systems known to man.
The study - somewhere between cosmology and neurosurgery – finds that despite the enormous difference in scale of the two systems and their completely different physical processes, they form structures with surprisingly similar levels of complexity and self-organisation.
The functions of the human brain are determined by a network of about 69 billion neurons. The visible Universe is made up of a ‘cosmic web’ of at least 100 billion galaxies.
In both cases, galaxies and neurons occupy only a small fraction of the mass of the two systems : less than 30 per cent.
In both cases, galaxies and neurons organise themselves into long filaments, or nodes between filaments, and in both cases, about 70 per cent of the mass or energy distribution of the two systems is made up of components that have an apparently passive role; water in the case of the brain, dark energy for the observable Universe.
Using these common characteristics, the researchers compared a simulated version of the network of galaxies with sections of the cerebral cortex and cerebellum. They were looking to find out how the fluctuations of matter are distributed on such different scales.
“We calculated the spectral density of both systems. This is a technique often employed in cosmology for studying the spatial distribution of galaxies,” Dr Vazza said.
“Our analysis showed that the distribution of the fluctuation within the cerebellum neuronal network on a scale from 1 micrometre to 0.1 millimetres follows the same progression of the distribution of matter in the cosmic web but, of course, on a larger scale that goes from 5 million to 500 million light-years.”
The team also looked at features, such as the number of filaments connected to each node.
They found that the cosmic web has on average 3.8 to 4.1 connections per node, while the human cortex has an average of 4.6 to 5.4 connections per node.
Both systems also appear to cluster connections around central nodes, and both seem to have a similar information capacity.
The memory of the human brain is estimated to be around 2.5 petabytes, while Dr Vazza’s research suggests that the memory capacity required to store the complexity of the Universe would be around 4.3 petabytes.
“Roughly speaking”, the researchers wrote in an earlier paper on the same topic, “this similarity in memory capacity means that the entire body of information that is stored in a human brain (for instance, the entire life experience of a person) can also be encoded into the distribution of galaxies in our universe”.
“Once again, structural parameters have identified unexpected agreement levels. Probably, the connectivity within the two networks evolves following similar physical principles, despite the striking and obvious difference between the physical powers regulating galaxies and neurons,” Dr Feletti said.
“These two complex networks show more similarities than those shared between the cosmic web and a galaxy or a neuronal network and the inside of a neuronal body.”