Dragonflies can predict the path of their prey
This collaboration between Lund University and the University of Adelaide resulted in the discovery of nerve cells, neurons, in the brain of the dragonfly Hemicordulia that allows it to predict where their flying prey are moving to and catch them. These neurons make it possible to focus on a small object that moves over a complex background. We humans use similar brain processes to track and catch a ball thrown towards us.
This discovery is important for research on the nervous system. In particular, for understanding how single nerve cells can make advanced predictions based on the path of moving objects.
David O'Carroll, professor of biology at the Faculty of Natural Sciences in Lund, thinks that dragonflies can serve as model organisms for continued research in this field. The nerve cells discovered by the researchers in the brain of the dragonfly are able to make a selection of a single target from the mass of visual information that the brain receives, such as motion of another insect, and then predict its direction and future location. The dragonfly, like humans, makes this assessment based on the path along which the object moves.
"In other words, the dragonfly does something very similar to what we do when we track a ball in motion. Despite major differences in the complexity of the brain, evolution has led to the insect using its brain for advanced visual processes that are usually only considered in mammals," says David O'Carroll.
The researchers found that the nerve cells they studied work by focusing the dragonfly's eyesight into a small area just in front of the present location of a moving object being tracked. If the prey then disappears from the field of vision, the visual focus spreads forward over time allowing the brain to predict where the target is most likely to reappear. The dragonfly makes this prediction based on the previous path along which the prey has flown.
David O'Carroll and his colleagues are convinced that their research results have practical applications, not least in terms of technical innovations in areas of artificial vision and robotics.
"Our discovery can be used for the development of artificial control and vision systems, such as self-steering vehicles and bionic vision," said Steven Wiederman, Senior Lecturer at the University of Adelaide, and a partner in the project, an international collaboration funded by the Swedish Research Council, the Australian Research Council and STINT, the Swedish Foundation for International Cooperation in Research and Higher Education.
Bionic vision, as Steven Wiederman mentions in the above quotation, can potentially help people with hereditary retinal diseases such as Retinitis pigmentosa. One way of creating bionic vision is through the implant of a microchip under the retina that replaces light-sensitive cells that are not working.
The researchers present their findings in an article published in the journal eLife. The article will be published on July 25th and can be accessed here