We often complain that our memory worsens and we have more and more forgetfulness, such as not remembering where we have put the keys or where we have parked the car, but the brain ages just like the rest of the body and that is why there is nothing special about it. that we lose faculties, without that meaning that we should worry.
In fact, the first results of experimental tests carried out by a team of neuroscientists and that were designed to analyze these memory losses indicate that “forgetting” may not be a bad thing, but may represent a form of learning, and they describe in an article the results that support this hypothesis.
Last year, neuroscientists who wanted to demonstrate the new theory suggested that changes in our ability to access specific memories are based on environmental feedback and predictability. And that rather than being an error, forgetting may be a functional characteristic of the brain, allowing it to dynamically interact with a dynamic environment.
In a changing world like the one we live in, forgetting some memories would be beneficial, they reasoned, as this can lead to more flexible behavior and better decision-making. If the memories were obtained in circumstances that are not entirely relevant to the current environment, forgetting them could be a positive change that improves our well-being.
“Natural forgetting” is reversible in certain circumstances
The researchers have presented in Cell Reports the first of a series of new experimental studies investigating the effect of natural – “daily” – forgetting on how normal forgetting processes affect particular memories in the brain. The team studied a form of forgetting called retroactive interference, in which different experiences occurring very close in time can cause recently formed memories to be forgotten.
“Memories interfered with can still be reactivated by surrounding signals leading to memory expression”
To carry out the study, they asked mice to associate a specific object with a particular context or room and then recognize that object that was displaced from its original context. However, mice forget these associations when competing experiences are allowed to “interfere” with the first memory.
To study the outcome of this form of forgetting on one’s memory, neuroscientists genetically tagged a contextual “engram” (a group of brain cells that store a specific memory) in the brains of these mice, and followed the activation and functioning of these cells after forgetting occurred.
Using a technique called optogenetics, they discovered that stimulating engram cells with light recovered apparently lost memories in more than one behavioral situation. Furthermore, when the mice were provided with new experiences related to the forgotten memories, the ‘lost’ engrams could be naturally rejuvenated.
“Memories are stored in sets of neurons called ‘engram cells,’ and successful recall of these memories involves the reactivation of these sets,” said Dr. Tomás Ryan, associate professor in the School of Biochemistry and Immunology and the Institute of Trinity College Neuroscience at Trinity College Dublin, and lead author of the just-published paper.
“By logical extension, forgetting occurs when the engram cells cannot be reactivated. However, it is becoming increasingly clear that the memories themselves are still there, but the specific sets are not activated and therefore not activated.” “Recover the memory. It’s like the memories are locked in a safe, but you can’t remember the code to unlock it.”
“Our findings support the idea that competition between engrams affects recollection and that the forgotten memory trace can be reactivated by natural and artificial cues, as well as updated with new information. The continuous flow of environmental changes leads to the encoding of multiple engrams competing for consolidation and expression,” adds Dr Livia Autore, Irish Research Council (IRC) Postgraduate Fellow, who spearheaded this work at the Ryan Laboratory at Trinity.
“So while some may persist undisturbed, some will be subject to interference from new incoming and prevailing information. Interfered memories, however, can still be reactivated by surrounding cues leading to memory expression, or by experiences misleading or novel, ending in an updated behavioral result.
Because we now know that “natural forgetting” is reversible in certain circumstances, this work has significant implications for disease states, such as in people living with Alzheimer’s disease, for example, where these everyday forgetting processes can be erroneously activated by a brain disease.
