Understanding Brain Science with Inside Out

Inside Out is not just an entertaining movie, it's also a worthwhile movie. It had enough bright colors and pratfalls for my four-year-old and enough deep psychological subtext for me. I may never look at certain thought processes the same way again. The subtext is sturdy enough that it provides another dimension to the movie: it forms a framework for understanding brain science. As Exhibit A, I submit a recent Cell paper that Inside Out can illuminate.

(Before I continue, let me say that this contains MILD SPOILERS for a location visited relatively late in the movie. If you want to discover this location for yourself, go see it right now and come back!)

The paper I'm thinking of is titled "Sleep Facilitates Memory by Blocking Dopamine Neuron-Mediated Forgetting." Like any good title, it contains the key point of the paper, which can be illustrated using the imagery of Inside Out.

Researchers started from the knowledge that sleep helps build memories. In the Inside Out world, the sky turns black during sleep time and the memories roll out to Long-Term Memory storage, which fits precisely with this knowledge. Some memories don't fit in Long-Term and are rolled down to the Memory Dump. By studying memories of smell in fruit flies, the researchers dug into the tubes and found one gatekeeper who determines which memories roll where.

Imagine an Inside Out Forgetter (as pictured above) who sits at the entry to Long-Term Memory, kicking some memories out of the rolling chute and down into the black funnel that is the memory dump. This Forgetter is Dopamine -- the same molecule that gives you that euphoric dopamine rush so many people talk about. Maybe this particular Forgetter is moonlighting, constructing pleasant sensations by day and working as a Forgetter by night.

What the scientists did is they kidnapped the Dopamine forgetter, and more memories rolled into Long-Term storage. The science is a lot more detailed and complicated, mostly because dopamine has so many jobs, but the basic message is smaller than a Pixar short.

Speaking of which, can we enlist the Inside Out crew to make some educational videos for psychology courses? Something tells me profs teaching next year's courses will have a whole new set of references in them thanks to this movie. Which provides one more small reason to see it.