Humans Can Learn Echolocation in Ten Weeks
And it's not just people with impaired vision, sighted people can echolocate too
Hiya!
We’re living through an exceptionally transitional period of history that affects nearly every aspect of life, from cultural and political to technological and scientific. I’m particularly excited about the latter two because we’re finally transitioning from breaking things apart to seeing how they work together. Allow me to explain.
We humans tend to approach knowledge using a reductionist approach or breaking things down into the sum of their parts. The point is to understand the role each part plays as a whole. We do it with everything from machinery and algorithms to learning how to read, but we also reduce and segregate branches of knowledge, our emotions, and even our bodily senses.
Taste, touch, smell, sight, and hearing have long been known as our five dominant senses. However, scientists now recognize additional senses, such as balance and proprioception, bringing the total to seven and counting. Now, we’ve reached a point where scientists are learning how our senses overlap to better understand how they work together. In the process, they’ve discovered even more abilities we possess, like echolocation.
Echolocation & Blindness
You’re likely familiar with echolocation, a physiological process many animals use to locate objects and navigate in darkness, whether environmental, such as the deep ocean or a cave, or in the case of blindness or impaired vision.
By producing a noise, such as a click or a high-frequency call, an animal senses the soundwaves reflecting off objects in its environment, which helps it navigate its surroundings. Bats, dolphins, whales, and some birds can all echolocate — and it turns out that humans can, too.
One of the earliest records of human echolocation comes from French author and philosopher Denis Diderot, best known for his writings that influenced the Enlightenment.
While much of his work was significant during his lifetime, Diderot published a largely ignored pamphlet in 1749 titled Letter on the Blind for the Use of Those Who Can See. In it, he describes how people who are blind can locate “silent objects.” He also foreshadowed braille as a method for people with impaired vision to read in the future.
Nearly two centuries later, in 1944, zoologist Donald Griffin coined the term "echolocation" (aka locating via echoes) after studying bats. By the 1950s, scientists were formally studying human echolocation.
Like other echolocating animals, humans create a noise — by clicking sharply with their tongues — and then listen to the differences in the sound reflecting off nearby objects.
Did you try it? I sure did.
Anyway, since then, many examples of people who are vision-impaired using echolocation have been recorded. Take Daniel Kish, for example. Kish is the founder and president of World Access for the Blind, a nonprofit that teaches echolocation and other skills to people with limited or no vision to help them navigate life. Oh, and he also taught himself how to echolocate as a child after losing his sight.
In 2017, Kish sat down with Nathan Hurst of the Smithsonian for an interview, in which he described the level of detail echolocation provides him about his surroundings — which is a lot.
Echolocation provides enough details that people can do anything from ride a bicycle to play basketball despite being completely blind, even from a young age.
Yet, recent research shows it’s not just the vision impaired who can learn to echolocate. The pathway appears to exist in our brains, even if we haven’t used it before, and learning to engage this pathway is just a matter of time and practice, no different from learning any other skill.
2021
Previous brain-imagining studies of expert human echolocators show activity in their primary visual region in response to sound, which led researchers to think that when someone loses their vision, the brain rewires itself to allow echolocation to emerge.
Researchers, including Kish and Lore Thaler, a neuroscientist at Durham University in England, explained to Simon Makin of Scientific American that,
“There’s been this strong tradition to think of the blind brain as different, that it’s necessary to have gone through that sensory loss to have this neuroplasticity.”
But then Thaler co-led a study in 2021 (which I wrote about) and discovered that echolocation is not just for the vision impaired. Both blind and sighted people can learn to echolocate in a matter of weeks.
The Study
Thaler and her colleagues at Durham University trained participants (14 sighted people and 12 blind people) in various virtual and practical navigation tasks twice a week for 10 weeks. The blind participants also completed a 3-month follow-up survey to assess the effects of the study’s training on their daily lives. In the end, the researchers concluded:
“We found that both sighted and blind people improved considerably on all measures, and in some cases performed comparatively to expert echolocators at the end of training.”
Even more remarkable, neither age nor blindness hampered the participants’ abilities or progress between the first and final sessions.
Three months later, during the follow-up, the researchers discovered that 83 percent of the blind participants reported more independence and well-being thanks to their new echolocating skills.
This study shattered the assumption that the brain reconfigures the vision center by showing that sighted people can echolocate, too.
But Thaler wasn’t finished.
If it’s not just the vision impaired who can learn to echolocate, she wondered, what happens in the brain to allow it?
2024 Study
Thaler and her colleagues expanded the 2021 study in a June 2024 study published in Cerebral Cortex.
Like their earlier research, the team trained 12 blind and 14 sighted people for two and three hours, twice a week, over 10 weeks. First, they taught the participants how to make the clicking noise and then trained them in three tasks.
The first two tasks assessed the size and orientation of objects, while the third involved teaching the participants to navigate virtual mazes guided by simulated clicks followed by echoes tied to the click’s position.
Both groups of participants underwent fMRI scanning before and after training, allowing the researchers to observe any echolocation-related brain changes. During the scans, the participants performed tasks related to recognizing mazes with and without click echoes.
Results
Remarkably, both groups improved in every task by the end of the experiment, but the differences in the participants’ brain imaging between the beginning and end of the experiment were even more surprising.
By the end of their training, both groups of participants showed increased activity in their auditory cortex in response to sound, and higher gray matter density in their auditory areas. Grey matter plays a crucial role in memory, emotions, and movement.
However, the most intriguing observation throughout the study was that the visual cortexes of both blind and sighted participants activated in response to audible echoes. In other words, the vision parts of both groups’ brains responded when they heard the echoes. Thaler told Makin:
“We weren’t sure if we would get this result in sighted people, so it was really rewarding to see it.”
Meanwhile, Santani Teng, a psychologist at the Smith-Kettlewell Eye Research Institute in San Francisco, who studies echolocation and braille, told Makin:
“This study adds a significant contribution to a growing body of evidence that this is a trainable, nonexotic skill that’s available to both blind and sighted people.”
Further, this study illuminates the complexity of our senses and challenges the idea that the primary sensory regions in our brains are exclusively sense-specific. Thaler suspects that the visual areas actually receive and process information from multiple senses to help us form a spatial recognition of our surroundings.
Perspective Shift
See what I mean? I wrote at the beginning that we’ve spent most of history breaking things down into the sum of their parts, but now we’re learning how the parts work together. Thaler’s research helps move us beyond isolating our senses to learning how they work together in the brain. However, there is another transition occurring these days that Thaler’s research is also part of.
Throughout history, we’ve studied our shared external world, but that's changing now thanks to technological and scientific advancements. The echolocation research discussed today joins a growing number of studies focusing on our unique internal experiences, and like many others, it shows that we’re capable of even more than we imagined.
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I beg your pardon?
There is a narrative, I don´t remember if from the NYT or the Guardian about a project that was collecting testimonials from people inside the torture center of the Assad Regime that described some people tortured there having said ability.