Old age goes fast.
We tend to think about the brain’s memory the same way we think about a computer’s memory, which captures everything. But the human brain is more like a sieve; only a small fraction of our daily events make it into memory. You don’t remember most of your life—you remember key frame moments. The amount of footage of memory that you have from an event determines how long you think it lasted, which is why time seems to speed up as you get older. Remember when you were at the end of a childhood summer and looked back? There were so many novel things that your brain remembered. So many events that were totally new to you. When you looked back on the summer, you thought it lasted a long time. But as an adult you look back at the summer and think, “Where did it all go?” Why? You have already figured out most of the rules of the world, so your brain doesn’t bother to write much down. In retrospect, events like the summer appear to pass more rapidly.
How do you live longer?
If you want to extend how long something seems to have lasted, the key is to seek novelty. I’m not telling you how to live longer, but how to make it seem as though you’ve lived longer. Seek out new things that jar your brain off the path of least resistance. Your brain will be forced to write memories down and incorporate new things into its model of the world. There are many easy ways to get off the path. If you wear a watch or a Fitbit, switch it to the other wrist. Brush your teeth with your other hand. Rearrange your office. Take a new route home from work every day. These simple things knock you off the path of automization, so in retrospect you think, “Wow! That month, that summer, that year lasted a long time.”
How can society be enriched by these findings?
I am on the board of the Long Now Foundation, which thinks about time on a ten-thousand-year scale. It is easy for us to get caught up in our day-to-day tasks and local political cycles. But we must ask, now that we are a sufficiently advanced species, how do we think about things on a very long timescale? This exercise is rarely performed. When you think about erecting a building, do you think about how to build it to last ten thousand years? Or when you build a clock, which the Long Now Foundation is doing, do you question how to make it last for that time span? The Long Now Clock will have one chiming sound mark every one hundred years and a different chime mark every one thousand years. Just think of the possibilities if we built machinery—or our political or societal structures for that matter—with such timescales in mind.
About the Contributor
David Eagleman is a neuroscientist and New York Times bestselling author of Incognito: The Secret Lives of the Brain and Sum: Tales from the Afterlives. He is the writer and host of the Emmy-nominated PBS television series The Brain. Eagleman is an adjunct professor at Stanford University, a Guggenheim fellow, and the director of the Center for Science and Law.
