Scientists have successfully trained a small group of people navigating by echolocation, that is, the method by which they communicate with each other some species, such as dolphins and bats. Although the possibility of using this method, blind people have already been proven in the past, scientists had till the end to find out whether the sighted people to develop the same ability, as the latter rely on their visual perception of the environment.
“We believed that if we are talking about seeing the person, then nothing happens. Therefore, thought unlikely to be of any use,” said Virginia Flanagan, a researcher from the Munich Ludwig-Maximilian University.
However, the results of the experiment with the involvement of 11 impaired people and one blind volunteers showed a completely different picture. One of the people who have problems with vision and most effectively have mastered the method of using echolocation, could determine a 4% difference in the change in the size of the virtual room.
“The people who showed a lower efficiency, still able to tell the difference, representing 6 to 8 percent. While the least effective indicator among the volunteers was 16 percent,” the researchers say.
“The overall picture is similar to the same indicators of visual acuity – the level of the ability to determine the differences in the environment — which are determined in some tests for visual assessment”, — commented Flanagan.
At the beginning of the experiment, the scientists first trained the volunteers in fact the very method of echolocation by placing them zvukoizolyatora and shielded anechoic room. People that are in it, listened to audio recordings of certain ticking (perhaps even clicking frenzy) sounds, previously recorded under normal conditions in rooms of various sizes. In the end, the researchers thus trained the people to distinguish the difference between clicking frenzy of sounds recorded in small and large buildings. Once people have passed the initial series of exercises, they were sent for the procedure magnetic resonance imaging. The scanner was connected to a virtual three-dimensional computer model of the nearby premises of the Church building.
While in the scanner, the people themselves or their tongues created a clicking frenzy sounds, or for them, it makes the car. Thus was created the principle of “active” and “passive” sonar. After that people listened to these sounds are echo through the virtual room. Based on the difference in the echo, the volunteers were able to determine the size of the virtual room.
The study showed that this task people cope much better when you use an active echolocation method. That is, they create the sounds of a clicking frenzy turned out to be a more effective tool for positioning themselves within the virtual environment. Scientists also noticed that people are increasingly using this technique on the exhale. In addition, it was noted that the echo sound activates the motor cortex of sighted volunteers – a part of the brain responsible for movement. When the researchers compared the results of MRI scans (which allowed to determine which parts of the brain are activated in producing ticking sounds) with active and passive echolocation, in both cases was marked by the activity of this area of the brain. In General, the motor cortex was most active each time in the case of larger virtual scenes, than small. This, in turn, can talk about a certain connection between the virtual and the physical positioning of the person in space.
“It seems that the motor cortex is somehow involved in the process of sensory information processing,” — said Flanagin.
As for the blind volunteer, in this case, the unused echoes activated the visual cortex of the brain. The brain, probably, thus tried to present a picture of the Bouncing from the walls of the echo within the virtual space.
Yet, one should take into account the fact that the experiment is conducted on a very small group of people, so to make any definitive conclusions would be premature. At least it is necessary to conduct similar experiments on larger and more diverse group of volunteers. However, given what we already know about the human predisposition to the use of echolocation, it is clear that the sighted people are able to use sound waves as a means for positioning themselves in the surrounding space.
Below you can see the level of the most famous expert on human echolocation, Daniel Kish, who, despite his blindness, showing its potential Cycling using this method.