To Dickinson, a fly is no mere pest; it’s an aerodynamic marvel. “It's hard to imagine a more sophisticated flying device,” he says. “This organism can land on the ceiling. It can fly briefly upside down. It can hover in place. It can make rapid turns to the left and the right. And all of this is done autonomously,” much like the tiny flying robots Dickinson says engineers are working to develop.
In fact, that’s one potential application of Dickinson’s research. "We're hoping to understand how a fly's brain works and apply that information to the design of small flying robots,” for planetary exploration or search-and-rescue, he explains.
So what’s behind the fly’s in-air virtuosity? Dickinson attributes the bug’s aerial acrobatics to its “very, very fast eyes” and speed at processing sensory information. “Flies also have tiny gyroscopes. They have little tiny wind detectors on their head,” he adds.
“Most people would swat flies without ever thinking about what they were destroying, but I must confess, I don't swat flies unless I absolutely have to. In fact, I'll usually try to induce them to land on my arm, and take a nice long look at them as long as they're happy to stay there.”
But there are limits even to Dickinson’s arthropod awe. He says, “If I notice that they're starting to bite me, well, then it's curtains for the poor fly. But until that point, I'm really more interested in how the creature works than in trying to swat it.”
Flies, of course, aren’t the only animals forced to make snap judgments. We humans also have to turn visual signals into safe movements. But while we have big brains to help us decide to stop at a red light, for instance, flies manage such decisions despite their budget-sized brain capacity. Dickinson says, “The human brain has about 300,000 times more neurons than a fly's brain, and therefore, all of these decisions the fly must be able to make with rather limited neural resources.”
Dickinson says the work won’t stop with flight simulation, so be ready for more buzz on fly cognition.
“This problem of determining what’s a safe perch and what’s a predator is just one of the many, many decisions that a fly has to make throughout the course of its life,” he says. “It has to decide when to take off. It has to determine in which direction to fly in order to find a nice piece of smelly fruit where it can find a good meal, a place to lay its eggs, and maybe some mates.”
To Dickinson, that’s all fodder for more research. “We hope to keep plugging away at trying to determine how the fly’s brain makes all of these very, very challenging decisions,” he says.
Authors: Gaby Maimon, Andrew D. Straw, and Michael H. Dickinson
Publication: Current Biology, online March 13, 2008
RESEARCH FUNDED BY: National Science Foundation, Office of Naval Research, the Air Force Office of Scientific Research, and Caltech Della Martin Fellowship