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slash holidays. From KQED. Welcome to Forum. I'm Alexis Madrigal. Thinking about neuroscience these days feels to me that one very strong message emanating from the field is that human brains accomplish the goals of human life in wildly different ways.

Though all living humans are very similar genetically, and our brains, where you look at them and jars would look quite similar, the connections between our billions of neurons are wired

up in so many different ways.

And this spectrum of variation between people includes even capacities that most people

take entirely for granted, like the ability to visualize things in your mind.

New Yorker's staff writer Larissa McFarker explores the range of visualization in humans in

a big new feature in the magazine, and she joins us this morning.

Welcome, Larissa.

Thanks for having me.

We're also joined this morning by Tom E. Bayer, who's founder of the Afantasia Network.

Welcome, Tom.

Thanks so much for having me.

So, Larissa, let's talk about this condition, Afantasia, the subject of this big New Yorker feature.

Just tell us what it is.

Essentially, whereas the most people, the vast majority of people can, as you said, see pictures in their minds and, you know, use those pictures to remember things they've seen in the past or done in the past.

Some people can't. They don't see

those pictures. They know many of the same things that the rest of us do. If you ask them,

does a squirrel have a short or long tail? They know the answer, but they just can't see the

...