Blind People Possess the Ability to Echolocate

Author: University of Western Ontario
Published: 2011/05/26 - Updated: 2024/10/06
Publication Type: Informative
Peer-Reviewed: Yes
Topic: Blindness and Vision Loss - Publications List

Page Content: Synopsis - Introduction - Main

Synopsis: Some blind people have the ability to utter clicks and to use echolocation, the returning echoes from those clicks, to sense their surroundings.

Why it matters: This article on echolocation is significant because it sheds light on a remarkable adaptive technique used by some blind individuals to navigate their environment. It explains how echolocation works, allowing people to create mental maps of their surroundings by interpreting sound echoes. This information is valuable for raising awareness about alternative methods of perception and mobility for the visually impaired. The article's exploration of this skill can inspire and empower blind individuals to develop new ways of interacting with the world, potentially enhancing their independence and quality of life - Disabled World (DW).

Introduction

It is common knowledge that bats and dolphins echo-locate, 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 echo-locate 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.

Main Item

Researchers at The University of Western Ontario's Center 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 neural basis of natural human echolocation.

Senior author Mel Goodale, Canada Research Chair in Visual Neuroscience, and Director of the Center 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 microphones in the ears of the blind echo-locators 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 echo-locators while their brain activity was being measured in Western's state-of-the-art 3T functional magnetic resonance imaging (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 visual information 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 echo-locate, 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 echolocation 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.

Attribution/Source(s): This peer reviewed publication was selected for publishing by the editors of Disabled World (DW) due to its relevance to the disability community. Originally authored by University of Western Ontario and published on 2011/05/26, this content may have been edited for style, clarity, or brevity. For further details or clarifications, University of Western Ontario can be contacted at uwo.ca NOTE: Disabled World does not provide any warranties or endorsements related to this article.