July 8, 2021 – Humans have a sixth sense that most of us don’t use, but could learn to do.
Some blind people have already figured out how to exploit this, the same way dolphins navigate underwater and bats find their way in total darkness. And it’s only a matter of time before others figure out how to do that, too, scientists say.
Our five senses – sight, hearing, smell, taste and touch – help us understand and perceive the world around us. But according to two recent studies, people can tap into a so-called sixth sense and learn to navigate in the dark when our sight cannot come through.
Dolphins and some other animals use biological sonar, called echolocation, to move around even when dark, murky waters prevent them from seeing. Bats seem to feel the sound as they bounce off obstacles as they fly unhindered in dark spaces.
“People passively use echolocation all the time,” according to Lore Thaler, PhD, associate professor of psychology at Durham University in the UK.
When a person walks into a room and intuitively understands whether the space is small or large and whether or not it contains furniture, they are probably basing their intuition on echoes and reverberations, says Thaler.
Blind people sometimes tap a cane or lightly stamp their feet to help them get a feel for the space around them. Humans can also echo by snapping their fingers or making clicking noises with their mouths, scientists say, as the sound waves it creates bounce off nearby objects.
People with little or no training can learn to use these echoes to determine the shape, size or texture of an object.
It is not a wacky superpower. Active detection is something that many people already master, says Daniel Kish, founder and president of World Access for the Blind. The California-based nonprofit helps train people who cannot see how to use echolocation, among other tactics, to navigate the world around them.
Pick up a superpower
In a new study, Thaler and his colleagues tested whether people can learn to echolocate.
Participants attended 20 training sessions – two per week for 10 weeks – and then tried to use echolocation to identify an object’s size and orientation in the lab. In addition, they performed a computer navigation task, in which they listened to sounds and navigated around objects.
“We had a huge age range – 21 to 79 – and included both sighted and blind people, and they all learned,” Thaler said.
For people who cannot see, developing their active sensing ability increased their ability to move around independently and improved their sense of well-being.
In a second study, Miwa Sumiya, PhD, who has since joined Thaler’s lab, and her colleagues asked 15 participants untrained in echolocation to send sound waves, from computer tablets, that were similar to noises bats use when flying in the dark. They were then asked if a cylinder in the room that they could not see was moving or stationary.
Even without training, most participants knew the answer. It is probably not difficult for people to understand the technique and use it when interacting with their surroundings, say Sumiya and her colleagues.
Still, some participants were much better than others at it, they say.
This is something Kish says his nonprofit has seen in the real world, outside of the lab as well. “The blind understand this much faster,” he notes.
The human brain is predisposed to use vision, and people who can see rely heavily on their sight to navigate the world around them. But blind people need to trust their other senses, Kish points out.
“I believe early humans were very auditory and probably used echolocation,” he says. “Most of human existence has taken place without artificial light, so we spent a lot of time in the dark. We spent time in caves and we had to know what was around us to avoid threats and predators, and you can hear around corners a lot easier than you can see around them, and you can hear through the foliage a lot more easily than you can see through.
In fact, there is evidence that as early as the 1700s, blind people were using echolocation to move around society, says Andrew Kolarik, PhD, of Anglia Ruskin University in the UK.
And studies have already shown that in the absence of sight, the brain will stimulate other senses to compensate.
“The brain kind of reconnects when blindness occurs,” Kolarik explains.
This remake amplifies the hearing system to improve a person’s ability to hear and use other senses in new and powerful ways.
Our sincere thanks to