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Mustang. Impala. Jaguar. Automakers have long used animals known for their speed, grace, and strength to sell their cars. So it might seem a bit odd that Mercedes-Benz turned to the chicken, of all creatures, to advertise its latest innovation.

In the fowl commercial, which has nearly 5 million views on YouTube, disembodied hands hold chickens aloft, dancing them to Diana Ross’s “Upside Down.” While their bodies undulate to the disco beat, the birds, with an unperturbed air, keep their heads remarkably—and comically—still.

The ad, for the German car company’s “Magic Body Control” suspension, is certainly compelling. But since this is Լ����Ƶ (never mind that we’re ocassionally confused with the German autobahn), we’ll focus on the chickens’ head control, rather than that of a car.*

It’s not magic, says J. David Dickman, a neuroscientist at . “Most, if not all, flight-capable birds can do this.”

Dickman studies the vestibular system, located in the inner ear, which many vertebrates use to maintain balance. Some receptors in the ear detect linear accelerations (like gravity), and others detect rotational head motion. These receptors send signals to the brain about head orientation with relation to gravity. These receptors—along with sensors in muscles, joints, and tendons throughout the body—relay changes in position, allowing the bird to adjust (hence the small head movements you see in the video).

“Basically it’s designed so that the head and eye stay locked to gravity, no matter what the body is doing,” says Dickman. “It’s really just a gaze-stabilization mechanism.”

In other words, by locking their head in place, the birds can focus their vision and not become dizzy—an important adaptation for animals that fly. We have a similar mechanism that helps control eye movements and keep us upright.

(To test this, keep your eyes locked on the word FOCUS and slowly move your head side to side. You can read it even as your head moves. But if you move your eyes with your head as you look from side to side, it’s a dizzying blur.)

As for the chickens’ incredibly flexible body movement, that’s due to the large number of cervical, or neck, vertebrae. We have seven; most birds have at least twice as many. “That’s why they can move their neck in a very sophisticated way,” says Dickman.

The chickens’ minor head movements have to do with the communication between the inner ear vestibular system and the proprioceptive system, which sends signals from receptors in the muscles, tendons, and joints.

Studying the vestibular system in pigeons, as Dickman does, could have implications for human health. People with dementia, for instance, often have vestibular symptoms, such as nausea and dizziness. “It’s involved in the navigation circuit, too,” says Dickman. “People with Alzheimer’s might leave the house or drive down the street and forget where they are and how to get back. The vestibular system sends those signals out—how far you’ve gone, and your map of space. We’re trying to figure out how the brain does that so that we can hopefully come up with some treatments.”

Dickman says he and others are “studying the vestibular system like mad,” but treatments that would repair injured neurons are a long way off. 

In the meantime, he has a new prop for the classroom. He’s long brought a pigeon to demonstrate gaze stabilization. Now, he says, “I’ll show the Mercedes-Benz video, too.”

P.S. Mercedes-Benz isn't the only company using chickens and their head stability to sell its product. Check out this LG G2 smartphone commercial:

*For those of you who must know more, here’s about the new S-Class suspension:

MAGIC BODY CONTROL is based on the ABC (Active Body Control) suspension featuring active suspension which improves both comfort and driving dynamics. In the case of Active Body Control from Mercedes-Benz, the four spring struts are fitted with hydraulic cylinders to enable the force in each spring strut to be adjusted individually. As a result, the vertical, rolling and pitching movements to which the body can be subjected are almost completely compensated for. The control unit receives information on the current driving conditions from various acceleration sensors and compares it with the data from the pressure sensors in the spring struts and the level sensors on the control arms. Subsequently the system calculates control signals for the servo-hydraulic valves on the front and rear axle, in order to meter the flow of oil appropriately. All of this results in a magical combination of optimum comfort and impressive driving dynamics.