While you live or find new things, your brain must codify this information through the right neural networks at the right time.
Every day, people learn and constantly form new memories. When you start practicing a new hobby, try a recipe recommended by a friend or read the latest news from the world, your brain stores many of these memories for years or decades.
But how does your brain get this extraordinary company?
In our new research in the Science magazine, we have identified some of the “rules” that the brain uses to learn.
Brain learning
The human brain is composed of billions of nerve cells. These neurons conduct electrical impulses that transport information, just like computers use the binary code to transport data.
These electrical impulses are communicated to other neurons through connections with each other calls synapses. The individual neurons have branched extensions known as dendrites that can receive thousands of electric inputs from other cells. The dendrites transmit these inputs to the main body of the neuron, where it integrates all these signs to generate their electrical impulses.
It is the collective activity of these electrical impulses in specific groups of neurons that form the representations of different information and experiences within the brain.
Neurons are the basic units of the brain.
OpenStax, CC By-Sa
For decades, neuroscientists believe that the brain learns by changing the way the neurons are connected to each other. As new information and experiments change the way in which neurons communicate with each other and change their standards of collective activities, some synaptic connections become stronger, while others become weaker. This process of synaptic plasticity is what produces representations of new information and experiences in the brain.
However, in order for the brain to produce correct representations during learning, correct synaptic connections must undergo the right changes at the right time. The “rules” that the brain uses to select which synapses should have changed during learning – which neuroscientists call the problem of credit assignment – are not yet very clear.
Definition of the rules
We decided to monitor the activity of the individual synaptic connections within the brain during learning to see if we could identify the models of activities that determined which connections would become stronger or weaker.
To this end, we genetically codify the biosons in the neurons of the mice that would light up in response to the synaptic and neural activity. We monitored this activity in real time while the mice learned an activity that involves pressing a lever in a certain position after a valid suggestion to receive water.
We are surprised to find that the synapses in a neuron do not follow the same rule. For example, scientists have always thought that neurons follow Ebba’s rules thus exchanged, in which neurons that shoot constantly connect. Instead, we saw that the synapses in different places of the dendrites of the same neuron followed different rules to determine whether the connections have become stronger or more weak. Some synapses have joined the traditional rule of Hebbian, in which neurons that shoot constantly together strengthen their connections. Other synapses have done something different and completely independent of the neuron activity.
Our results suggest that neurons, at the same time two different series of rules for learning in different groups of synapses, rather than a single uniform rule, can more accurately adjust the different types of items they receive to correctly represent new information in the brain.
In other words, following different rules in the learning process, neurons can perform various tasks and perform various functions in parallel.
Future applications
This discovery provides a clearer understanding of how connections between neurons change during learning. Considering that most brain disorders, including degenerative and psychiatric conditions, involves some form of malfunction of synapses, this has potentially important implications for human health and society.
For example, depression can develop from the excessive weakening of synaptic connections in some areas of the brain, which makes the feeling of pleasure difficult. By understanding how synaptic plasticity normally works, scientists can better understand what is wrong in depression and develop therapies to treat it more effectively.
The changes in amygdala connections – colored in green – are implicated in depression.
William J. Giardino/Luis de Lecea Lab/University of Stanford Via Nih/Flickr, CC By-NC
These results can also have implications for artificial intelligence. The artificial neural networks at the base of the AI ​​have been widely inspired by how the brain works. However, the learning rules that researchers use to update connections within the networks and trains models are generally uniform and are not even biologically plausible. Our research can provide insights on how to develop more realistic artificial intelligence models from a more efficient biological point of view, they work better or both.
There is still a long way to go before you can use this information to develop new therapies for human brain disorders. Although we discovered that synaptic connections in different dendritic groups use different learning rules, we do not know exactly why or how. Furthermore, although the ability of neurons to use various learning methods simultaneously increase their ability to codify information, it is not yet clear what other properties can give it.
Future research should answer these questions and expand our understanding of how the brain learns.
William Wright receives funding from the National Institutes of Health (Ninds) and Schmidt sciences.
Takaki Komiyama receives funding from Nih, NSF, Simons Foundation, Chan Zuckerberg Initiative and Kavli Institute for Brain and Mind.
Source: Terra
Rose James is a Gossipify movie and series reviewer known for her in-depth analysis and unique perspective on the latest releases. With a background in film studies, she provides engaging and informative reviews, and keeps readers up to date with industry trends and emerging talents.
