Study shows bats have acoustic cognitive maps
phys.org
phys.org
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.
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.
“The model revealed that bats tend to fly near environmental features with higher "echoic entropy"—areas that provide richer acoustic information.”
So, they recognize the sound of key reference points. This all seems rather intuitive and unremarkable?
> 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
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.
Could make a really cool art+science installation where you could induce audio vertigo. Like https://garyhill.com/work/mixed_media_installation/tall-ship...
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
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.
All of this is your opinion.
So did i just make this up until now (now, that it was shown in a study), or was this not common belief?
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.
[0]: https://link.springer.com/article/10.1007/BF00611870 - paywalled, unfortunately. And German!
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.