Hi there, it's Matt here and welcome back to the podcast. And welcome back to another episode

about the human brain and how truly amazing it really is. Imagine this. You're at a family

dinner and your cousin casually states that she has always known Wednesday is sky blue, not metaphorically,

not I've got a bright blue feeling about Wednesdays. What she means with total sincerity is this. When she reads the word, when she sees the

letter W, a precise hue of sky blue floods her mind's eye. Everyone pauses and kind of looks at her with a kindly but

worried look on their face. She shrugs, what? It's just how my head works. In that moment,

you glimpse a quiet truth about the human brain. Most of us spend our lives on the freeway

of perception, eyes front, never asking how the

lanes got painted. Synesthetes show you the off-ramps. And once you see them, you cannot

unsee them. Here's the claim we're going to test today, and it's going to surprise you in so many

different ways. You, yes, you listening to surprise you in so many different ways.

You, yes, you listening, you are a synesthete.

Not quite in the dramatic Wednesday is sky blue way, but in subtler, more universal ways

that shape how you experience reality every single day.

The legendary neuroscientist V.S. Ramachandran proved it with an experiment so simple you can do it right now. The test that changed everything.

Here's what the experimenters did. They said, I'm going to show you two shapes on the computer screen in front of you, and

then they start the experiment.

First, you see a shape that is all rounded and blobby.

Next, the computer screen changes, and you see a shape that is sharp and jagged, like a child

drew a star with anger issues. So two shapes, one that is round and

blobby, the other that is sharp and spiky. You're now asked the following. One of the shapes is

called booba and the other is kiki. Which one is booba and which one is kiki? If you're like 98% of humanity from American college students to Tamil speakers in India,

...