Our brain doesn’t have only learning mechanisms but also to erase the “unnecessary” memories for saving energy. In practice, eliminates everything considered useless, deletes unnecessary information to create space and operates in a “saving” mode. A group of researchers at Lund University in Sweden, have now been able to unravel the intricacies of this phenomenon at cellular level.
Learning and forgetting are sometimes two sides of the same coin
Several centuries ago, Pavlov, a Russian physiologist, experimented with dogs and discovered the classical conditioning. In practice, dogs learned that when a bell sounded, they would receive food, so they began to salivate just hearing the bells, though there was no sign of food around. This is because they created a connection in the brain between a neutral stimulus (bell) and an unconditional stimulus (food).
We also learn this way, we can establish connections between different stimuli and as a result, display the related answer. For example, some experiments conducted with people have linked a sound with the air in the eyes. So that eventually, people ended up blinking at the sound although there was no air. Obviously, this is an automatic learned response.
Paradoxically, when a light is added, people’s learning worsens and the connection is not reinforced. It is as if the additional stimulus would enhance oblivion.
Undoubtedly, it is a contradictory result since, in theory, learning should be strengthened. However, these researchers think the problem is that the brain forgets to save energy.
What's going on?
Initially, is activated a brain mechanism that allows learning by creating a pattern at neuronal level. It's like if that part of the brain that captures and learns the association, the cerebellum, said: “I got it, I don’t need more stimulus”.
In fact, these researchers noted that when an association is consolidated in the brain, when learning occurs, are activated some neurons whose function is to apply the handbrake, indicating that is enough and we should stop.
However, when two associations are introduced, it is as if the brain is oversaturated. At this point, the possibilities to forget increase, even of the information we just learned before, albeit temporarily.
Researchers believe that keeping active in the brain the neural connections considered “unnecessary” generates and additional energy spending. So far, instead of learning, we step back and forget.
How can we apply these results to practical life?
First, it is convenient to avoid saturating the brain with too much information, because this way we will only hinder the learning. It is better focusing on one thing at a time, and only when that learning is consolidated we can move on.
Secondly, it is important to create meaningful associations. It is not about “stacking” information, because the brain would consider it useless or unnecessary. It is important to search for logical connections, so to create new neural patterns from the existing ones, rather than overcome them one another.
Rasmussen, A. et. Al. (2015) Purkinje cell activity during classical conditioning with different conditional stimuli explains central tenet of Rescorla–Wagner model. PNAS; 112(45): 14060–14065.
Our brain forgets to save energy
4/ 5Oleh Jennifer Delgado