Time flies faster as we age . . . or so it seems

[ Sun. Jul. 12. 2009 ]

By Norbert Cunningham

Hello everyone! I've a little science today, but first note that language is a communication tool; it's what allows us to relate our experiences and thoughts, all, of course, as processed by our brains.

And while we don't yet understand how our brains work very well, scientists have lately been making remarkable progress, in part thanks to new technologies such as MRI scanners that allow them to observe healthy (as well as damaged) brains as they work.

Time flies

Now to connect this to language: we've all heard or used the cliché that "time flies."

Anybody over 40 has also likely remarked at how much faster time flies as you get older. It's a common observation many find puzzling: why does summer as a youngster seem "endless," yet pass in the blink of an eye to adults who swear it was only a couple weeks ago that they put the snow shovel away?

Does time speed up in some magical, bizarre way as we age?

Do people in traumatic events like car crashes actually witness time slowing down as they so often report?

The intuitive answer is that these are matters of perception more than reality in which time has been said to flow like a river, sure and steady (only, as Einstein showed, does time actually slow significantly enough to truly notice if you travel at incredibly high speeds beyond anything most of us will ever experience).

That intuition it is our perception has been shown to be correct, so why do we perceive time to speed up as we age? Our everyday language and the millions of people commenting on the fact are not wrong: the perception is real.


I take the following from an essay titled "Brain Time" by Dr. David M. Eagleman which appears in a book called "What's Next? Dispatches on the Future of Science," edited by Max Brockman.

Dr. Eagleman is a bright young scientist who has undergraduate degrees from Rice University and Oxford University in literature, but who obtained a doctorate in neuroscience from the Baylor College of Medicine 11 years ago. Today he is director of the Baylor College of Medicine's Laboratory for Perception and Action. The lab's long-term goal is to "understand the neural mechanisms of time perception," which in plain English is to figure out how our brains make us think time has slowed or sped up when it hasn't. It was his and his colleagues' work that allowed me to say that our intuitions are correct: people in traumatic situations do perceive time to slow, but a hair-raising experiment shows they have no extra time to react or do anything extra beyond what would normally be possible.

An explanation

We perceive the slow motion because time and memory are "tightly linked," says Dr. Eagleman. In such critical situations a part of our brain called the amygdala kicks into high gear and takes over most of the brain's resources. This forces a secondary memory system to do the processing, a system that can later produce flashbacks of the sort soldiers with post-traumatic stress experience. This backup memory is "stickier" than what our brains usually use to store memories, producing more vivid and clear images in our minds; more detail. And in remembering these, since there are many more images, just like inserting extra images in a movie reel, it makes the event appear to last longer and slows motion down. That much is fairly certain.

Less certain, but strongly suspected by Dr. Eagleman, is that the same or a similar process is what makes time seem to speed up as we age. As we experience ever more in life, familiar patterns recur and the memories our brains store get ever more compressed. Our brain can skip or compress a lot of things we know or have already experienced because we've got the general template from the first time and it need add only new details. As a result, when we draw on our memory, it is much less vivid and detailed, having the effect of cutting some frames out of a film, which seemingly speeds time up. Children, on the other hand, are frequently having first-time experiences, encountering novel things. Their brains store that information in all its detail and richness since it is the first time. Recalling it, even decades later, we remember those "endless summers" and wonder whatever happened to them. This is not "proven" yet, but it sounds logical and fits with what is known about the sensation of time slowing when in a critical situation. It's a good tentative explanation.

Full circle

So it's back to language, which does describe what we perceive well. But time to us is not really a steady flowing river after all. It's relative, according to how our brains stored our memories. And time flies as we age . . . it seems.

The last word

Here is author and wit Douglas Adams:

Time is an illusion. Lunchtime doubly so.

* Lex Talk! is researched and written by Times & Transcript editorial page editor Norbert Cunningham. It appears in this space every Monday.