This is Geena Davis' brain. This is Geena Davis' brain on TV.

Geena Davis came to Seattle’s Grey Sloan Memorial with one very handy tool in her medical bag. After learning that her Grey’s Anatomy character Dr. Herman, a curmudgeon of a fetal surgeon, had a baseball-size brain tumor, the 59-year-old offered to let the show use her real-life brain scans as props. (The tumor was added in later.)

Davis had these cerebral snapshots readily available thanks to a UCLA-based research study called the Big C Project. The study, which aims to figure out whether extraordinarily creative individuals’ brains are visibly unique, approached Davis because she’s both an Oscar-winning actress and an Olympic-level archer. She was immediately game—she’d been curious about her brain from a young age after watching an episode of Quincy, M.E. in which a footballer died from a brain aneurysm. “I swear I walked around very carefully for about two years because I didn’t want to set off my potential ticking time bomb,” Davis recalls.

What the study discovered: Davis’ brain is something of an overachiever. For one, it’s so large that it didn’t fit in the box doctors use to frame brains for examinations. “Her brain is literally outside the box,” says Dr. Robert Bilder, who runs the study, which also includes musicians Stewart Copeland and Moby, among others. “95 percent of the people in the world fit in this box, but not Geena.” For another, Davis has increased development in a location of her gray matter that regulates and inhibits impulse—i.e., it’s easier for her to control movement and nonverbal expression—which basically means her superbrain helped her win an Academy Award. Talk about a beautiful mind.

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