Crocodile in Brain Scanner Reveals Reptiles Respond to Music

A Nile crocodile as it is about to enter an fMRI machine. Felix Ströckens

Playing Bach to reptiles is a hard job, but someone has to do it. Especially if you're a neurologist who wants to better understand how various brains react to music.

It's well-known that music can inspire reactions from humans, birds and other animals. Whether listening to Spotify or the songs of a potential mate, a wide variety of animals respond to complex melodies.

How universal is this trait? When did it evolve? There's no way for scientists to go back in time and ask every animal if they care about music. However, they can start with the Nile crocodile, a living relic that has stayed fairly similar over the last 200 million years.

Scientists from Germany and South Africa borrowed a young Nile crocodile from a zoo and taped its mouth shut. They gave it a mild sedative and gave it a functional magnetic resonance imaging (fMRI) scan. The researchers scanned the animal's brain to see how it would react to different stimuli, such as a tone at a fixed frequency or Bach's Brandenburg Concerto No. 4, Digital Trends reports.

The results, published in the journal Proceedings of the Royal Society B, show that the crocodile's brain responded to the music in a similar way to how a bird responds. Birds make their own songs and crocodiles don't, so it's particularly interesting that the crocodile would seem to care about music.

This is the first time that scientists have studied the brain of a cold-blooded animal like a reptile using an fMRI, Gizmodo reports. These results suggest that responding to music, or at least complex sounds like birdsong or Bach, is deeply wired into the animal brain, spanning across mammalian, avian, and reptilian brains. Since crocodiles have changed so little since the time of the dinosaurs, it's possible that this trait has been in animal brains for hundreds of millions of years.