What Pixar's Inside Out Got Right About Memory

Photo: Courtesy of Walt Disney Pictures.
You've probably already heard that Pixar's new movie, Inside Out, will make you cry. And it will. But it might also give you a little insight into how your brain works: The movie largely takes place inside the mind of the 11-year-old main (human) character, Riley, and it shows just how rough it can be to make big transitions as a little kid.

While science has yet to confirm the existence of tiny, animated, personified emotions running around your brain and controlling everything you feel, the movie did depict a lot of things pretty accurately. Pixar made sure to consult with psychologists to get the facts (mostly) right about how your memory really works.

Spoilers ahead, duh.

1. Your memories can change.
We tend to think our memory works like a video camera, passively and accurately recording everything we see. (Perhaps even storing those memories in colorful, little marbles.) But, research shows our memory is far more flexible than that (just ask Brian Williams).

All of this means that every time you remember something — in the film, every time another marble is projected onto Riley's big brain screen — that memory becomes vulnerable again. It can change, and the way we feel in the present can change the way we remember something that happened in the past. This is called reconsolidation, which means the memory has to be "consolidated" again, a process that can actually change its content. Then, it's put back into long-term memory storage with all the other old marbles.
2. Sleep is essential for memory.
To make that reconsolidation happen — or for memories to be consolidated and stored in the first place — you'll need to sleep. That's when your brain is hard at work strengthening the connections between your neurons. Then, when you're awake, it'll be easier to remember those events. (This is one of many reasons why all-nighters are usually a bad way to study.)

Although we don't see any neurons in Inside Out, we do see Riley's brain shut down a lot of its work during sleep. Joy and Sadness have to go out of their way when the Train of Thought stops running after Riley hits the hay. But, the brain isn't necessarily "off" when we're snoozing; it just has different jobs to do, including making weird dreams out of the things you've seen that day.
3. Memories can come back.
First, yes: It's true that if you don't use a memory for a while, its neuronal connections will get weaker until you just can't remember it. For instance, after years of neglect, I can probably say adios to my ninth-grade Spanish. But researchers have shown that this loss isn't always permanent. Instead, we can still have traces of memories and get pieces of them back, sometimes in unexpected ways. In the movie, all of those unused, gray memory marbles get tossed into the abyss, but Joy still finds an unusual way out.

In reality, it's unlikely we'll remember something long-forgotten exactly as it was. But, even if we don't remember everything, we can still act as though we've had some practice. In one famous case, a patient who suffered brain damage after an experimental surgery was able to get progressively better at drawing tasks after practicing daily, but never explicitly remembered the training. This is obviously an extreme case, since your forgetting probably isn't the result of trauma. But, this and other research suggests we can remember once-forgotten concepts, because the memories are still physically present in our brains. We've just lost the connections we need to access them.
4. You'll remember dumb stuff forever.
Unfortunately, you probably already knew this one. Like the silly gum commercial that keeps popping into Riley's head, there are stupid things we'd all rather just forget — but can't. These songs are nicknamed "earworms," and they've been researched a lot recently. Psychologically, they show up when our minds are just wandering, and we end up latching onto something we've heard a million times before.

But why do we remember the unimportant stuff at all? According to other research, this is a symptom of our brains not totally being able to predict what we'll need to know in the future. We're more likely to remember things that we think will be useful in the future or that have a strong emotional component. Usually, we're pretty good at picking out the right stuff, but not always.

That means you're much more likely to remember something fun and catchy than whatever boring subject you're supposed to be studying right now, even if you know you're going to need it for that test tomorrow. And, the more you remember that jingle when you're zoning out, the more that memory connection grows stronger.
Sure, Inside Out isn't a 100% accurate representation of the way your brain works. But once you've wiped away your tears, hopefully you can also appreciate all the ways your memory can go wrong — and how often it actually goes right. Now, what were we doing again?