Washington, June 27 : A researcher at the University of Maryland, College Park, says that studying the vocal sonar of bats may help gain significantly deeper understanding of mechanisms in the human brain, as well as benefit human health.
"For decades it's been recognized that a bat's voice produces sounds that give the bat information about the location of objects. We're now recognizing that every time a bat produces a sound there are changes in brain activity that may be important for scene analysis, sensorimotor control and spatial memory and navigation," says Cynthia Moss, a member of the Neuroscience and Cognitive Science program at the university.
A research article on her team's study says that working with Nachum Ulanovsky of the Weizmann Institute of Science in Israel, Cynthia and her colleague reviewed more than 100 studies, and determined that the brief calls emitted through a bat's mouth or nostrils and their returning echoes play a pivotal role in motor control and have other behavioural implications.
Published in the online edition of the Proceedings of the National Academy of Sciences, the study report suggests that echoes from a bat's voice causes it to turn its head and ears, and give the its brain a description of the scene.
The echoes also cue a bat's memory about its environment so as to enable it to safely fly between points, adds the report.
"Our review highlights new research findings suggesting that the bat's vocal production does more than yield echoes. We're learning every time the bat produces a vocalization, there are changes in brain activity that are essential to complex behaviours," says Moss.
She says that bats use information carried by the echoes of their high-pitched vocal chirps, produced at rates of 2-150 chirps per second, to compute the 3D location of objects in its environment - such as a tree, a wall or a lamppost - when they pursue prey.
According to her, these echoes actually allow bats to remember details of the environment in which it operates, displaying a very sensitive spatial memory component.
Cynthia believes that her team's findings may be useful for future human studies.
Just like bats engage in vocal-motor behaviours to generate signals to probe the environment, she points out, some blind humans produce tongue clicks to generate sounds for echolocation.
She also says that both bats and humans engage in so-called "motor behaviours" that shape their perceptions of the world.
"All of these motor behaviors influence the animal's perception and representation of the environment. But of interest to us is the idea that these vocal-motor behaviors contribute to environmental perception, memory, and spatial planning far beyond the processing of sound," she says.
"It may be that some of the information we learn from the bat gives us a window into understanding mechanisms of the human brain. But those outcomes are a little bit down the road," she adds.