The rapid growth of toddlers' minds comes at the expense of their memories
It's easy to remember the events of previous decades, birthdays, high school graduations, visits to grandma's, but who can remember the days when he was a baby? For about a hundred years, researchers have been trying to decipher the cause of childhood forgetfulness. Sigmund Freud blamed it on the repression of early sexual experiences, an idea that was rejected. The researchers then attributed this to the fact that babies have no personal perception, no language, and no mental skills needed to encode memories.
Paul Frankland and Sheena Joslin, both neurobiologists at Children's Hospital in Toronto, believe that language skills or sense of self do not offer an adequate explanation. It turns out that humans are not the only animals that experience childhood forgetfulness. Mice and monkeys also forget their early childhood. To explain the launch points between the species, Frankland and Joslin developed another theory: the growth of many new nerve cells in the young brain blocks access to old memories.
In a recent experiment, the scientists changed the growth rate of nerve cells in the hippocampus of young and adult mice. The hippocampus is an area of the brain where autobiographical events are recorded. Young mice, whose brain nerve cell growth rate was slowed, had better long-term memory. Whereas older mice whose nerve cell growth rate was accelerated, lost their memory.
Based on this data, published in the journal Science in May 2014, Frankland and Joslin believe that rapid growth of nerve cells in early childhood disrupts the circuits in the brain that store the old memories and prevents access to them. Also, the prefrontal cortex of children, another area that encodes memories, is not developed, so childhood forgetfulness can result from the combination of both factors.
As we age, the growth rate of nerve cells slows down and the hippocampus reaches a balance between creating memories and storing them. We forget, of course, many things, but perhaps it is better that way. "The sad truth is that most of the things we do are routine anyway," says Frankland. "The idea is that for a healthy adult memory to function properly, it is necessary not only to remember things, but also to erase unimportant memories." Who needs to remember all the hours of sleeping, crying and crawling?
The article was published with the permission of Scientific American Israel
One response
Hypothesis: when we get to learning a new method that will really transform our desire from the pure egoism with which we were born to altruism and influence. Even then a similar thing will happen. The brain will forget and lose memories rather than creating new wiring between the neurons that created a more sophisticated brain.