A sudden burst of improvisational creativity may feel almost supernatural in origin, but there’s a biological basis for it, say researchers.

How did they study it? By scanning the brains of freestyling rappers, of course.

They found that rapping memorized lyrics and rapping freestyle use entirely different parts of the brain. In fact, improvising actually shuts down the part of the frontal lobe that regulates other brain functions. So freestyling doesn’t just come from the more intuitive, emotional parts of your head; it actually shuts down the part that’s used to control the rest of your head, leaving you free to spit your best verses.