Neuroscientists know a lot about how our brains learn new things, but not much about how they choose what to focus on while they learn. Now, researchers have traced that ability to an unexpected place in the brain.

In order to learn about the world, an animal needs to do more than just pay attention to its surroundings. It also needs to learn which sights, sounds, and sensations in its environment are the most important and monitor how the importance of those details change over time. Yet how humans and other animals track those details has remained a mystery.

Scientists think they’ve figured out how animals sort through the details. A part of the brain called the paraventricular thalamus, or PVT, serves as a kind of gatekeeper, making sure that the brain identifies and tracks the most salient details of a situation. The findings appear in the journal Science.

Sandeep Datta says the brain composes behavior from pre-existing “syllables.”

Illustration by Chiara Zarmati/Salzman Art

Every year, various members of the illusion community—which is made up of scientists, neurologists, researchers, and even artists—get together to decide which of their recently created mind-melters deserves the honor of Best Illusion of the Year. This year, Japan’s Kokichi Sugihara claimed the top prize with a deceptively simple illusion that plays with how our mind perceives 3D objects.

This isn’t the first time Kokichi Sugihara, a mathematician at Meiji University in Japan, has won the Best Illusion of the Year honor. Nor is it the first time his fantastic illusions have shown up on Gizmodo. Triply Ambiguous Object, his latest award-winning creation, appears to be a simple 3D structure, with a tiny flag mounted on one of its many corners.