Echolocation acts as substitute sense for blind people

Recent research carried out by scientists at Heriot-Watt University has demonstrated that human echolocation operates as a viable 'sense', working in tandem with other senses to deliver information to people with visual impairment.

Ironically, the proof for the vision-like qualities of echolocation came from blind echolocators wrongly judging how heavy objects of different sizes felt. The experiment, conducted by Heriot-Watt's Dr Gavin Buckingham and his colleagues at the Brain and Mind Institute at Western University in Canada, demonstrated that echolocators experience a 'size-weight illusion' when they use their echolocation to get a sense of how big objects are, in just the same way as sighted people do when using their normal vision.

Dr Buckingham's findings are published this week in the journal Psychological Science. He said, "Some blind people use echolocation to assess their environment and find their way around. They will either snap their fingers or click their tongue to bounce sound waves off objects, a skill often associated with bats, which use echolocation when flying. However, we don't yet understand how much echolocation in humans has in common with how a sighted individual would use their vision."

The researchers had three groups taking part in the experiment: blind echolocators, blind non-echolocators, and control subjects with no . All three groups were asked to judge the weight of three cubes which were identical in weight but differed in size.

Dr Buckingham said, "The blind group who did not echolocate experienced no illusion, correctly judging the boxes as weighing the same amount as one another because they had no indication of how big each box was."

"The sighted group, where each member was able to see how big each box was, overwhelmingly succumbed to the 'size-weight illusion' and experienced the smaller box as feeling a lot heavier than the largest one.

"We were interested to discover that echolocators, who only experienced the size of the box through echolocation, also experienced this illusion. This showed that echolocation was able to influence their sense of how heavy something felt. This resembles how visual assessment influenced how heavy the boxes felt in the sighted group."

The findings are consistent with earlier work showing that blind echolocators use 'visual' regions of their brain when listening to their own echoes. This new work shows that is not just a functional tool to help visually-impaired individuals navigate their environment, but actually has the potential to be a complete sensory replacement for vision.


Explore further

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

More information: "The Size-Weight Illusion Induced Through Human Echolocation." Psychological Science 0956797614561267, first published on December 19, 2014 DOI: 10.1177/0956797614561267
Journal information: Psychological Science

Citation: Echolocation acts as substitute sense for blind people (2014, December 22) retrieved 26 February 2020 from https://medicalxpress.com/news/2014-12-echolocation-substitute-people.html
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
1 shares

Feedback to editors

User comments