For every human on earth, memories of childhood are the most easily recalled. As we think of events in the past it often seems time is stretched, as if through a warp. Recollections tend to artificially lengthen the time period for an event. Not so as we age.
In comparison, our more recent years of adulthood often feel like they’ve passed are gone before we know it. We often credit this experience with just another outcome of getting older. Like creaking knees, hair loss and expanding waistlines, we may not take much notice of it.
Now, a fascinating new study is offering up a more scientific explanation: as we age, the speed in which our brains obtain and process images gradually slows, resulting in this temporal discrepancy in memories.
Simply put, this slowing of the brain’s imaging speed causes perception of time to speed up as we age.
“People are often amazed at how much they remember from days that seemed to last forever in their youth,” says main study author Adrian Bejan, the J.A. Jones Professor of Mechanical Engineering at Duke University, in a release. “It’s not that their experiences were much deeper or more meaningful, it’s just that they were being processed in rapid fire.”
As we mature, the nerves and neurons in our brains also mature, growing in size and complexity. Consequently, new neural signals (memories), are faced with a longer path to travel than when we were young. Our nerves also deteriorate as we age, slowing down the flow of electrical signals throughout our minds.
These developments mean that it takes longer for new mental images and memories to be obtained and processed. One piece of evidence Bejan noted to back up his theory is how much more often infants’ eyes move in comparison to adults; children process images much faster than adults, leading to quicker eye movements and a rapid integration of information.
So, because older people are processing far fewer images within a given amount of time than they used to in their youth, it feels like time is passing at a faster rate.
“The human mind senses time changing when the perceived images change,” Bejan concludes. “The present is different from the past because the mental viewing has changed, not because somebody’s clock rings. Days seemed to last longer in your youth because the young mind receives more images during one day than the same mind in old age.”
The study on time and age is published in the scientific journal European Review.