In what is being called a "fundamental leap forward in our understanding of how brains work," Japanese researchers have successfully caught on film a thought being formed in the brain. And while the brain in this study belongs to a zebrafish, not a human, the footage is captivating, and sheds light on how researchers could use a similar technique to see how our brains work. 

To observe the zebrafish brain's neurons in real time, researchers used a fluorescent probe that makes neurons light up when they're active. What was the zebrafish thinking about? Something we humans obsess about all the time: Food. Researchers showed the fish a squirming piece of prey, and watched as the fish's brain perceived it and considered consuming it. "In other words, you're seeing what the fish thinks when it sees its lunch," explains Jamie Condliffe at Gizmodo. In the video, parts of the fish's brain light up like lightning in a storm before the light ripples through the neurons. It is, for lack of a better phrase, so cool.