Playing Music Through a Squid

The way we usually play music is through loudspeakers or headphones. But what happens if you play music through squid cells? To find out, check out the video embedded below that has become somewhat of an internet sensation. Since it was posted on YouTube in late August, it has raked up over two million views, and was even shown at the Imagine Science Film Festival in New York City in November.

The video’s maker, Greg Gage, is co-founder (with Tim Marzullo) of Backyard Brains, a company that sells experimental kits to teach neuroscience to the masses. The squid experiment isn’t the first time Gage has played music through a biological “device.” His company, he says, has already sold over 2,000 SpikerBox kits, which enable the user to connect an iPod to electrodes placed inside a cockroach leg to make it dance to the music. The iPod converts the music to an electrical current, which stimulates the nerve cells of the leg, which cause the leg muscles to move.

Last summer, Gage was experimenting with the Longfin Inshore Squid at the Marine Biology Laboratory in Woods Hole, Massachusetts, and became fascinated by the animal’s chromatophores — pigment cells on the squid’s skin that can expand if muscles attached to them contract. The squid uses its chromatophores to change color if it needs to hide from predators.

Gage wondered: What would happen if he tried the same thing he did with the cockroach leg with the squid’s chromatophores? To find out, he isolated the squid’s fin nerve, which controls the fin muscles and the muscles that control the chromatophores. He then attached an electrode to the nerve, and connected his iPod nano to the electrode.

And indeed, when he played music, the chromatophores started to dance. After trying several types of music, he found that heavy bass lines, especially those in hip hop songs, stimulated the chromatophores best. Eventually, Gage settled on Cypress Hill’s song “Insane in the Brain,” and made a video of an 8x magnified microscopic view of the fin’s chromatophores he called “Insane in the Chromatophores.”

The video quickly went viral: After a week, it had more than 1.3 million views. Soon, Gage says, he started to get emails from bands, asking if he could play their music through the squid. Someone working with the singer Peter Gabriel contacted Gage to ask for images from the video to be used in the printed program of Gabriel’s upcoming tour.

Artists also wanted to show the video in their exhibitions. In October, Dutch artist Suyin Tjon A Hie projected the movie onto an acrylic table to allow visitors to interact with it, at an exhibit that was part of Dutch Design Week in Eindhoven. “Loved the imagery immediately; vibrant colors, zoom in, ‘heartbeat’ movement,” she wrote in an email.

Apart from its artistic value, the video teaches an important lesson about nerve cells, Gage says, that they respond best to bass frequencies around 55 Hertz. “It’s that bass that people dance to, and it’s also the bass that makes enough current to cause those axons to fire, which causes those muscles to move,” he says, referring to axons, the extensions nerve cells use to send signals. “What I like about it [is that] when you see it, you just kind of get it. It’s a really visual way to explain something a little bit complicated.”

This sensitivity to frequencies in the lower bass range (40-140Hz) seems to be true for nerve cells in general, he adds. When doctors stimulate nerve cells deep in the brain to treat Parkinson’s disease, they use frequencies within this range.

When watching the video, it’s even possible to use the chromatophore movements to discover changes in the song that aren’t so easy to hear at first. For example, the chromatophores show some of the wildest movements around 2 minutes and 20 seconds in, and it’s exactly during that part of the song that the drums stop playing, while the bass continues. That part is easy to hear, but in addition, the bass seems to be stronger and deeper. “There is a really deep bass sound that kind of twangs,” Gage says. “It’s hard to pick up, but if you listen to it on better speakers than your computer, then you hear this really deep bass. It’s kind of cool, because you probably wouldn’t go back and check it, but because you see it, you go back, and there it is.”

To better understand such effects, Gage plans to analyze the frequency spectrum of the song and correlate that to the chromatophore movements. “More detailed analysis will let us know if there is an optimal frequency that correlates with the opening of the chromatophores,” he says.

By the way, Gage and his colleagues at Backyard Brains aren’t the first to play music through living tissue. “Up until a week ago, I would have said we were,” Gage told us last month. But then he saw a comment someone had posted on Backyard Brain’s website saying that someone had done something similar years ago.

That someone, it turns out, was Jonathan Ashmore from University College London. He played music into a hair cell taken from the inner ear of a guinea pig. The video was broadcast by the BBC in 1987.

His choice of music? Bill Haley’s 1954 Rock and Roll classic “Rock Around the Clock.”