This means our brain’s memory capacity is 10x larger than previously thought.
A new study by scientists from the Salk Institute for Biological Studies in California reveals that the human brain’s memory capacity may be 10 times larger than previously thought.
"This is a real bombshell in the field of neuroscience," Terry Sejnowski from the Salk Institute for Biological Studies said in a press release. "Our new measurements of the brain's memory capacity increase conservative estimates by a factor of 10 to at least a petabyte, in the same ballpark as the World Wide Web."
To better explore the brain’s memory capacity, the researchers built a 3D reconstruction of brain tissue from a rat’s hippocampus — the memory center of the brain. This led them to a strange discovery: the synapses, which are junctions that form between neurons, were being duplicated in around 10 percent of the cases.
The team then measured the differences between these duplicate synapses by reconstructing the rat brain tissue’s connectivity, shapes, volumes, and surface area at a nano-molecular level. To do so, they used advanced microscopy and computational algorithms.
Amazingly, the researchers discovered that the difference in sizes of the pairs of synapses was only about 8 percent different, which is extremely small. "No one thought it would be such a small difference. This was a curveball from nature,” said Tom Bartol, one of the scientists.
Previously, scientists believed that there were only a few categories of sizes of synapses, but this finding reveals that there may be as many as 26! This means our synaptic dimensions are much more complex than we thought — suggesting a huge boost in our brain’s potential memory capacity.
"This is roughly an order of magnitude of precision more than anyone has ever imagined," said Sejnowski. "The implications of what we found are far-reaching. Hidden under the apparent chaos and messiness of the brain is an underlying precision to the size and shapes of synapses that was hidden from us."
Another interesting finding in the study, published in eLIFE, revealed that our synapses adjust themselves according to the signals that they receive, in both size and ability. "This means that every 2 or 20 minutes, your synapses are going up or down to the next size," said Bartol.
The researchers hope the findings about the the brain could also lead to advancements in technology.
"This trick of the brain absolutely points to a way to design better computers," said Sejnowski. "Using probabilistic transmission turns out to be as accurate and require much less energy for both computers and brains."
To learn more about how synapses work, check out the Salk Institute’s new video below.