How blind people map their surroundings using sound

Some blind people use returning echoes from their own mouth clicks to perceive external surroundings, or echolocation. New from eNeuro, Haydee Garcia Lazaro and Santani Teng, from Smith–Kettlewell Eye Research Institute, explored how the human brain creates representations of external surroundings using echolocation. 

The researchers first discovered that four blind individuals comfortable with using echolocation could identify object location better than 21 people with vision intact in a dark room. Accuracy at using echolocation improved with more self-generated mouth clicks in these expert echolocators. The researchers also linked neural activity in the brain to the ability of blind individuals to determine object location. This activity, alongside behavioral measures, strengthened across click sequences, leading to more accurate object location. Says Garcia-Lazaro, “Basically, we found that, in some experts, there appears to be a summation, or accumulation, of information in the brain that builds up across clicks about object location.” 

According to the researchers, this work shows how the brain uses repeated sound information to create representations of the environment in the absence of vision. Garcia-Lazaro expresses excitement about the next steps stemming from this work, including determining what makes blind people adept at echolocation and training people with and without sight to engage their echolocation ability. 

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About eNeuro 

eNeuro is an online, open-access journal published by the Society for Neuroscience. Established in 2014, eNeuro publishes a wide variety of content, including research articles, short reports, reviews, commentaries and opinions. 

About The Society for Neuroscience 

The Society for Neuroscience is the world's largest organization of scientists and physicians devoted to understanding the brain and nervous system. The nonprofit organization, founded in 1969, now has nearly 35,000 members in more than 95 countries.