The brain can store nearly 10 times more data than previously thought, study confirms

The brain may be able to hold nearly 10 times more information than previously thought, a new study confirms.

Similar to computers, the brain's memory storage is measured in "bits," and the number of bits it can hold rests on the connections between its neurons, known as synapses. Historically, scientists thought synapses came in a fairly limited number of sizes and strengths, and this in turn limited the brain's storage capacity. However, this theory has been challenged in recent years — and the new study further backs the idea that the brain can hold about 10-fold more than once thought.    

In the new study, researchers developed a highly precise method to assess the strength of connections between neurons in part of a rat's brain. These synapses form the basis of learning and memory, as brain cells communicate at these points and thus store and share information. 

By better understanding how synapses strengthen and weaken, and by how much, the scientists more precisely quantified how much information these connections can store. The analysis, published April 23 in the journal Neural Computation, demonstrates how this new method could not only increase our understanding of learning but also of aging and diseases that erode connections in the brain.. 

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"These approaches get at the heart of the information processing capacity of neural circuits," Jai Yu, an assistant professor of neurophysiology at the University of Chicago who was not involved in the research, told Live Science in an email. "Being able to estimate how much information can potentially be represented is an important step towards understanding the capacity of the brain to perform complex computations."

In the human brain, there are more than 100 trillion synapses between neurons. Chemical messengers are launched across these synapses, facilitating the transfer of information across the brain. As we learn, the transfer of information through specific synapses increases. This "strengthening" of synapses enables us to retain the new information. In general, synapses strengthen or weaken in response to how active their constituent neurons are — a phenomenon called synaptic plasticity.