There are some people without sight who use clicks of their tongue to build a mental map of nearby objects.
It would be fascinating to compare fMRI images of bats and humans performing a similar task. Not sure if that would qualify for an ignoble prize, but it'd be an interesting study to read!
EDIT: https://en.wikipedia.org/wiki/Daniel_Kish is who I am thinking of. I've tried it myself in a very dark room with a sleeping mask on: You can definitely hear differences, and with practice it might help you to navigate. I also became a lot more aware of air currents, and had to move slowly to prevent disrupting "useful" air movements.
I was once blindfolded for a team activity and led from a small hallway to an empty basketball gymnasium. With no training or prior awareness, I could instantly tell not only that I was in a gymnasium, but also (very) approximately how far I was away from the walls. after that, I started paying attention to how often I use audio cues to spatially locate myself.
It's almost 40 years since it was published and almost as long since I read it, but The Blind Watchmaker by Richard Dawkins [1] has a chapter or section about echolocation in bats that I found fascinating.
As I recall, it talks about how the scientists who discovered echolocation were initially laughed at (the greatest human engineers had just invented radar, how could the bats have evolved it?), how echolocation may have evolved stepwise, some of the specific physiological adaptions, and included some speculation about what kind of cognitive maps would be required within the bat's brain.
I don't know how well the science in that section holds up 40 years later, but it was beautifully written for the layman and was fairly high-level. If you're interested, I would definitely recommend taking a look.
I think it was known that echolocation is used for 'collision detection' and finding food, but not necessarily that bats could navigate long distances using echolocation alone. The editor's summary of the article is more clear imo:
> Insectivorous bats are well known to use echolocation to catch prey and navigate around obstacles. It has also been shown that more visually guided fruit bats have spatial cognitive maps of their environment. Goldshtein et al. placed minuscule GPS trackers on tiny pipistrelle bats in conjunction with temporary blocks of vision and olfaction. The authors found that the bats could still navigate across kilometer scales using only echolocation. Thus, echolocation may not only allow for local navigation, but might also translate into an acoustic cognitive map of the environment that the animals can use to navigate over long distances. —Sacha Vignieri
That is how research works, and most often, it also finds interesting results in knowledge, future questions or new experimental techniques.
I just discovered a stand of trees in a park near me that has a rich acoustic texture, if you clap your hands, the returned echo consists of multiple overlapping time shifted echos. Step 3m in either direction laterally and you can perceive the same echo but at an angle.
Yeah it’s intuitive, but it’s the first confirmation of such a thing! Yay, science. They discuss the previously-plausible theory that echolocation provided local momentary info only, and didn’t translate into long term spatial memories. A subtle distinction perhaps, but an important one if we want to get closer to knowing What It’s Like To Be A Bat.
Reading it brought me joy for no other reason than imagining researchers strapping blindfolds and nose plugs to “tiny” bats. Thank you for your service, bats
If you're interested in how different creatures perceive the world, the book "An Immense World" by Ed Yong covers a very wide range of sensory experiences including echolocation.
Not OP, but... It suggests that it's less different than one might have originally thought. Bats using echo location can build a persistent model of the environment, in just the way we can. I'd be prepared to bet a small amount that this gives bats the same illusion we have of moving in a static 3d space.
There is a qualitative difference between what it is like to be a human and what it is like to be a bat. You can't "get closer" to bridging a qualitative difference. Likewise, qualitative difference cannot be "less different." Those terms only apply to quantitative differences.
Additionally, learning additional facts about bats, such as that they create acoustic cognitive maps, doesn't tell us anything about what it is like to be a bat. That's literally the whole point of Nagel's paper.
> You can't "get closer" to bridging a qualitative difference. Likewise, qualitative difference cannot be "less different." Those terms only apply to quantitative differences.
I am confused. I have said that bats build maps solely by echolocation for a long time, when argumenting about how what we grasp with our senses could not be all there is to reality. I thought it's the perfect example without drifting immediately into a spritiual realm argument...
So did i just make this up until now (now, that it was shown in a study), or was this not common belief?
Bat echolocation is a topic that's very personal to me. My grandpa worked as a researcher in telecommunications and fibreoptics in the 1970s, in East Germany (GDR). This being at the height of the cold war, it was completely prohibited to publish anything relevant to their actual work, so that the "class enemy" wouldn't be the wiser of what they were doing in the lab. When publishing anything, they had to water down the content so much that it became useless to anybody reading it. Also, publishing on data transmission with fibreoptics, while nobody in the country is able to get a telephone line in their homes, wasn't seen as helpful.
It was sometimes possible to travel to western/international conferences - of course only after the Stasi gathered from interviews with all your colleagues and neighbors that you loved your children, and were likely to come back. And even then they were not allowed to make any contact with western scientists at the conferences, making any kind of useful exchange near-impossible.
After finding and reading a book on Bionics, which was a bit of a hype topic at the time, he noticed that the biologists were talking about the inexplicable nature of bats' echolocation. As he had experience with code multiplexing, he wrote a paper on the signal theory behind that, in 1974 [0]. As this topic was considered completely harmless, it was no problem to get this published in the GDR. After a request, it was even published in a journal in West Germany. But then being invited to give a talk on it in Frankfurt/Main, the authorization was given three times by the institute, and then revoked again each time (by higher-ups/Stasi). He was then asked to cease any communication with West-German researchers (who had sent him a book manuscript to review). It was a bitter-sweet thing for him. In later years, he was often asked about bat echolocation, as it made for a good pop science topic. But of course he would have loved to publish, and exchange, on his actual research topics at the time much more.
My grandpa died a couple of years ago. When I travel to international conferences now - being able to present whatever I like, talking to whoever I choose - this history often comes back to mind. Sometimes these stories feel like a very distant past. But then I read about how Linux maintainers are removed just for having a Russian email address, as happened recently. So maybe we haven't come as far as we think. I believe it's important to be conscious of the great freedoms most of us currently enjoy, how precious they are, and how brittle they can be.
I think the comments saying that this was already known, or obvious, are kinda missing the point.
It's always good to have some assumptions be experimentally verified, so we are all on the same page. Yes, echolocation plays a part, but (based on the abstract) this helps demonstrate that it's echolocation alone, i.e. it's not too affected when another sense is disrupted (for example smell). In other words, this checks if there's a bat-equivalent to the human "turning down the radio so you can see better" while parking a car.
For all we know, their maps could have linked to a secondary stimulus more tightly than we might have initially thought. Similar to how people might have difficulty remembering something until they do a second action, and it's the combination of these two actions (trying to remember + doing the second action) the actual trigger for remembering, instead of either action by itself. So isolating it to just echolocation is still worth verifying by itself.
The study also probably provides some specific data on conditions (of the bat, location, etc), distances, etc, to provide some upper or lower bounds on when the "exploratory actions" stop and the "memorized map" takes over, so we get an idea of approximate area size memorized (more data), stuff like that.
Imagine someone is doing a useless study like "Can humans feel pain on a body part they don't have?" with an obvious answer of "no of course not, that's BS", but going ahead anyway and discovering that phantom limbs and phantom pain are a thing (I don't know how this actually played out in history, I'm just trying to illustrate a point).
So TL;DR: the value of scientifically verifying "obvious" things is that, if things go as expected, you get specific data that can be used instead of assumptions; and if things don't go as expected, then that means the "obvious thing" wasn't so obvious after all.
It would be fascinating to compare fMRI images of bats and humans performing a similar task. Not sure if that would qualify for an ignoble prize, but it'd be an interesting study to read!
EDIT: https://en.wikipedia.org/wiki/Daniel_Kish is who I am thinking of. I've tried it myself in a very dark room with a sleeping mask on: You can definitely hear differences, and with practice it might help you to navigate. I also became a lot more aware of air currents, and had to move slowly to prevent disrupting "useful" air movements.