'I can hear a building over there': Researchers study blind people's ability to echolocate

May 25, 2011

It is common knowledge that bats and dolphins echolocate, emitting bursts of sounds and then listening to the echoes that bounce back to detect objects. What is less well-known is that people can echolocate too. In fact, there are blind people who have learned to make clicks with their mouths and to use the returning echoes from those clicks to sense their surroundings. Some of these individuals are so adept at echolocation that they can use this skill to navigate unknown environments, and participate in activities such as mountain biking and basketball.

Researchers at The University of Western Ontario's Centre for Brain and Mind (London, Ontario, Canada) have recently shown that blind echolocation experts use what is normally the 'visual' part of their brain to process the clicks and echoes. The study, appearing this month in the scientific journal PLoS ONE, is the first to investigate the of natural human echolocation.

Senior author Mel Goodale, Canada Research Chair in Visual Neuroscience, and Director of the Centre for Brain and Mind, says, "It is clear echolocation enables blind people to do things otherwise thought to be impossible without vision and can provide blind and visually-impaired people with a high degree of independence."

Goodale and his team of researchers first made recordings of the clicks and their very faint echoes using tiny in the ears of the blind echolocators as they stood outside and tried to identify different objects such as a car, a flag pole, and a tree. The researchers then played the recorded sounds back to the echolocators while their was being measured in Western's state-of-the-art 3T (fMRI) brain scanner.

Remarkably, when the echolocation recordings were played back to the blind experts, not only did they perceive the objects based on the echoes, but they also showed activity in those areas of their brain that normally process in sighted people. Most interestingly, the brain areas that process auditory information were no more activated by sound recordings of outdoor scenes containing echoes than they were by sound recordings of outdoor scenes with the echoes removed.

When the same experiment was carried out with sighted control people who did not echolocate, these individuals could not perceive the objects, and neither did their brain show any echo-related activity, suggesting visual brain areas play an important role for in blind people.

According to Goodale, this research will provide a deeper understanding of brain function, particularly how the senses are processed and what happens neurologically when one sense is lost.

More information: Thaler L, Arnott SR, Goodale MA (2011) Neural Correlates of Natural Human Echolocation in Early and Late Blind Echolocation Experts. PLoS ONE 6(5): e20162. doi:10.1371/journal.pone.0020162

Related Stories

Recommended for you

Now you like it, now you don't: Brain stimulation can change how much we enjoy and value music

November 20, 2017
Enjoyment of music is considered a subjective experience; what one person finds gratifying, another may find irritating. Music theorists have long emphasized that although musical taste is relative, our enjoyment of music, ...

Schizophrenia originates early in pregnancy, 'mini-brain' research suggests

November 20, 2017
Symptoms of schizophrenia usually appear in adolescence or young adulthood, but new research reveals that the brain disease likely begins very early in development, toward the end of the first trimester of pregnancy. The ...

Deletion of a stem cell factor promotes TBI recovery in mice

November 20, 2017
UT Southwestern molecular biologists today report the unexpected finding that selectively deleting a stem cell transcription factor in adult mice promotes recovery after traumatic brain injury (TBI).

Brain cell advance brings hope for Creutzfeldt-Jakob disease

November 20, 2017
Scientists have developed a new system to study Creutzfeldt-Jakob disease in the laboratory, paving the way for research to find treatments for the fatal brain disorder.

MRI uncovers brain abnormalities in people with depression and anxiety

November 20, 2017
Researchers using MRI have discovered a common pattern of structural abnormalities in the brains of people with depression and social anxiety, according to a study presented being next week at the annual meeting of the Radiological ...

Theory: Flexibility is at the heart of human intelligence

November 19, 2017
Centuries of study have yielded many theories about how the brain gives rise to human intelligence. Some neuroscientists think intelligence springs from a single region or neural network. Others argue that metabolism or the ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.