Denying us access to certain cells in the brain that store memories might be a practical feature of the human organism that helps us upgrade decision-making abilities, new research suggests.

Not being able to recall specific memories in certain environmental conditions does not indicate decay of the brain, but rather shows it’s developing to promote learning and flexible behavior, according to a theory put forward by a team of international scientists.

To better interact with the changing world, the brain switches parts in charge of remembering things “from an accessible to an inaccessible state,” Dublin professor, Dr. Tomas Ryan, suggests. He has been researching the theory together with his colleague from Toronto, Dr. Paul Frankland, and their study was published this week in the leading international journal, Nature.

“We propose that forgetting is actually a form of learning that alters memory accessibility in line with the environment and how predictable it is,” said Dr. Ryan.

Ensembles of neurons called “engram cells” are in charge of keeping memories, and they are reactivated when memories need to be recalled, the professor explains. When the cells cannot be reactivated, forgetting occurs – meaning memories are not lost, they are still there, but the brain doesn’t give us access. “The rate of forgetting” apparently depends on circumstances in an ever-changing world.

“It’s as if the memories are stored in a safe but you can’t remember the code to unlock it,” the scientist said.

Such memory loss does not appear to be permanent, but is reversible in certain circumstances, and is more of an altered memory access. There are certain cases when it’s not temporary, but then not remembering things is a different, pathological thing that indicates a disease.