The Man Who Learned Without Knowing

I want to start with a puzzle, and I'd like you to try it before you read any further, because once you know what happens, you can't un-know it.

There's a star beside this page, a star drawn twice, one outline just inside the other, so there's a narrow road between them. Your job is to trace the road all the way around without touching either edge. Simple. Except you can't see your hand. You can see a mirror of it. Move your finger right, and the dot on the screen goes left. Move up, it goes up — that part's fine — but every left is a right, and the corners of the star are where it gets you.

Put your finger on the copper dot and go around once. Count the times you bump the edge; the screen counts too. Then go around again. Do it ten times.

I'll wait.

What you probably felt

Clumsy. Every corner of the star, your hand goes the wrong way, you correct, you overcorrect, you bump. By the fifth or sixth time around you're still going wrong at the corners and it still feels like a fight. If someone asked you, halfway through, "are you getting better at this?" I think you'd say no. Or "a little, maybe."

Now look at the graph the screen drew while you weren't watching it.

The first time around, most people bump the edges twenty or thirty times. By the tenth time, it's three or four. The line drops like a stone. Your hand learned the mirror. It learned it while you were feeling clumsy. The feeling and the graph disagree, and the graph is right.

Hold on to that. It's the whole story, and I'm going to tell you about the man who showed it to us.

Henry

In 11,953 (1953), a young man in Connecticut named Henry Molaison had an operation on his brain. He was twenty-seven. He'd had seizures since he was a boy — storms of electricity in the brain that knock you down — and they'd gotten so bad he couldn't hold a job. The neurosurgeon, William Scoville, thought the storms started in a part of the brain called the hippocampus, and he took it out. Both sides.

The seizures got better. And Henry stopped being able to remember anything new.

Not everything. He remembered his childhood. He knew his name, his parents, the streets of Hartford. He could talk with you, joke with you, do a crossword. But if you left the room and came back ten minutes later, he'd greet you as a stranger. He met the same doctors every week for fifty years and never once recognized them. He read the same magazines over and over. Every morning, the news was news.

The hippocampus, it turned out, is where the brain writes down what happened. Say it "hippo-CAMP-us"; it's named after a seahorse, because it's curled like one. You have two, one on each side, deep in the middle of the head, about level with your ears. Henry's were gone, so nothing new got written down. The pen was missing.

Brenda and the star

A neuropsychologist named Brenda Milner came down from Montreal to study Henry. She came for years. He never remembered her.

In 11,962 (1962) she gave him the star. The same one you just did: two outlines, a mirror, a pencil, trace the road. He bumped the edges about thirty times. She had him do it ten times that day, ten the next day, ten the day after.

Each morning he said he'd never seen it before. Each morning he was right, as far as he knew; the hippocampus writes down what happened, and his couldn't.

And each morning he was better at it. By the third day he went round the star almost clean, like someone who'd practiced for weeks, which he had. Then he looked at what he'd done and said something Milner never forgot:

"Huh. This is strange. I thought that would be difficult, but it seems as though I've done it quite well."

He had learned the mirror. He had no memory of learning it. Both of those were true at once.

Two memories

So there are two of them. Two different kinds of remembering, kept in different places, and you can lose one and keep the other.

One is what happened. Where you were yesterday, who said what, this story. That one runs through the hippocampus, and it's the one you can feel: you know when you remember something, and you know when you don't.

The other is getting better at things. Riding a bicycle, tying a knot, tracing a star in a mirror, playing a tune. That one lives somewhere else — mostly in a knot of structures under the cortex called the basal ganglia, and in the cerebellum at the back, the wrinkled thing that keeps your movements smooth. Henry kept all of it. And here's the part that matters to you: you can't feel this one working. There's no "aha." There's no moment you notice it. There's just, one day, your hand knowing.

That's why the graph and the feeling disagreed. You were asking the hippocampus, "am I getting better?", and the hippocampus doesn't know. It wasn't the one learning. Something else was, quietly, and it doesn't report in.

What this means for you

You'll spend a lot of your life doing things that feel clumsy and not getting an "aha." Learning to play something. Learning to draw. Learning to read a page that won't give up its meaning the first time. The feeling of not getting it will be there, loud, and it will feel like evidence.

It isn't. You just proved that. Ten trips around a star and your hand learned something your mind never noticed, and the only reason you know is that a machine was counting.

Henry didn't know either. He got better anyway.

Michael tried the star this week. He's seventy-seven. He says his first trip round was a disaster, thirty-one bumps, and his tenth was four, and that it felt exactly as bad the tenth time as the first. When Eileen tried it she was quicker to settle down. It might have been easier for her because she's an astronomer, and she learned to find stars from charts that were sometimes printed backward.