About a week ago, after spending more than 15 minutes scouring my studio apartment for a set of keys before finally finding them beside the couch, I got into the car and flipped on the radio. Billy Joel’s “Piano Man” came on.
It’s not one I listen to often, but for some reason I knew every word. I turned to the next station, and I could sing the song playing on that one, too. I then popped in a Ben Folds CD and I remembered song after song.
Which made me wonder — how many songs can our brains actually remember? And if I had a way to dump some of them, would I be to remember things that are potentially more important, like where I left my keys?
The short answer: no.
“Your brain has almost an unlimited capacity for memory,” said Dr. Emily Mason, who studies memory and cognition at the University of Louisville. “It can actually store about 2.5 petabytes of memory.”
A petabyte is a million gigabytes, so it’s pretty large. To put that in terms of digital memory, Mason said, if your brain was a smartphone on which you downloaded TV shows, it could record 300 years of continuous TV before starting to run out of space.
But your brain’s short-term, quick recall memory has more limitations.
“You need more cues to remember things like that, and for something like your keys, where you might leave them in a different spot every day, that’s sort of confusing to your brain to remember,” she said.
And, in contrast, there are a few reasons why we remember music so well. Some of it has to do with how our brains are hardwired to latch onto repetition and rhyme — elements most songs have.
“In elementary school, that’s why things are put to song,” Mason said.
There’s also a small element of muscle memory. It’s sort of like if you play basketball, you get to the point where you don’t have to coach yourself through each step of dribbling. After a while, you do it without thinking. When you sing along to a song enough times, muscle memory between your brain and mouth kind of kicks in.
But according to Mason there’s something about music that hits us on an emotional level, and that especially aids in memory.
“Your brain loves emotions,” Mason said. “That really helps you remember things.”
This could happen with songs that you associate with being happy or in love.
“A song with a positive valence can activate your reward cortex, and your brain evolved to sort of guide you toward rewards,” Mason said.
The same is true for songs that make you feel really sad. Our brain recognizes these very human emotions and helps us remember what prompted those.
And our brains aren’t just good at remember and reciting lyrics. Thanks to these emotional bonds, often when we hear music — even music from years ago — it can take you back to a specific point in time. Mason said that’s why current research into Alzheimer’s and dementia is taking a closer look at how music can provide a gateway into old memories.
This, she said, is one way our brains help to preserve the most essential parts of what makes you, well, “you.”
“Whereas your keys, who cares?” she said with a laugh.