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

May 25, 2011, University of Western Ontario

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

Recording a thought's fleeting trip through the brain

January 17, 2018
University of California, Berkeley neuroscientists have tracked the progress of a thought through the brain, showing clearly how the prefrontal cortex at the front of the brain coordinates activity to help us act in response ...

Midbrain 'start neurons' control whether we walk or run

January 17, 2018
Locomotion comprises the most fundamental movements we perform. It is a complex sequence from initiating the first step, to stopping when we reach our goal. At the same time, locomotion is executed at different speeds to ...

Brain zaps may help curb tics of Tourette syndrome

January 16, 2018
Electric zaps can help rewire the brains of Tourette syndrome patients, effectively reducing their uncontrollable vocal and motor tics, a new study shows.

A 'touching sight': How babies' brains process touch builds foundations for learning

January 16, 2018
Touch is the first of the five senses to develop, yet scientists know far less about the baby's brain response to touch than to, say, the sight of mom's face, or the sound of her voice.

Miles Davis is not Mozart: The brains of jazz and classical pianists work differently

January 16, 2018
Keith Jarret, world-famous jazz pianist, once answered in an interview when asked if he would ever be interested in doing a concert where he would play both jazz and classical music: "No, that's hilarious. [...] It's like ...

New study reveals why some people are more creative than others

January 16, 2018
Creativity is often defined as the ability to come up with new and useful ideas. Like intelligence, it can be considered a trait that everyone – not just creative "geniuses" like Picasso and Steve Jobs – possesses in ...

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.