Study reveals why adults can't remember infancy
Friday, June 27, 2014, 4:02 PM - Most people possess little-to-no memories of early childhood and a new study may have pinpointed the cause.
Prior to the paper, there were a few theories as to why adults have little recollection of early childhood.
One of them suggests that memories are rooted in language, because children typically begin forming long-lasting memories around the time they start speaking.
“But the really weird thing is that most animals show infantile amnesia too,” study coauthor Sheena Josselyn of the Hospital for Sick Children in Toronto told Science News.
“So the development of language can’t be the whole explanation.”
Children typically fail to recall specific events until they are between two and four years old, according to Live Science. Scientists now suspect this could be the time when the brain's hippocampus starts to connect fragments of information together.
A research team studied a group of mice and found that as they age, the production of neurons in the brain slows down.
Adult mice were placed in a chamber they were unfamiliar with and their feet were buzzed with a mild shock. Adults learned to be apprehensive of the room, even 28 days after the fact.
Young mice were more forgetful, with their fears diminishing one day after being shocked. This led researchers to believe that the production of new brain cells may interfere with memory retention.
For the next experiment scientists increased neuron production in the adult mice through exercise, a natural method of producing new brain cells in the hippocampus.
After a few weeks of physical activity the adult mice forgot the "scary" room as well. Researchers were able to extend the memories of young mice by slowing down the birth of new neurons in their brains.
Josselyn told Science News that forgetting isn't necessarily a bad thing, adding that it could be "good to clear away some memories and forget some things that are not so important.”
The complete paper can be found online in the journal Science.