I was watching Discovery Channel and saw a special on bats and how they used mainly sonar to “see” the world around them. Then it occured to me, “How does a bat view the world?”
Saying it uses sonar is like saying we use light. It’s fine and dandy and a perfect answer, but it doesn’t really answer the question.
Is this a question that definitely has an answer (after all, a bat knows how a bat views the world) but can never be answered by humans?
Its reasonable to assume that most humans view the world the same way, and even perhaps to extend that idea to all other animals that view the world primarily though our five senses, but the sonar perception of bats (for example) is something we can recreate with machinery, but can only interpret the results through our senses, something a bat doesn’t have to do.
I guess the closest that we could get to a bat’s experience would be a blind person who uses a cane to feel out his/her surroundings. The blind person is using their sense of touch much the same way the bat is using its sonar.
I doubt if the audio information that a bat receives from its surroundings is transferred into a visual image, even not one seen by eyes, but by the brain. I doubt if the bat “pictures” in its head what his surroundings look like the way we humans do to try to gain perspective when we can’t see.
You could try blinfolding yourself, and shouting to see if you can tell where the walls are by the echo, but since we humans don’t specialize in this I doubt if it would be a successful experiment, primarily because you would still be trying to “visualize” your surroundings.
Richard Dawkins has a rather good exposition of this in Chapter 2 of “The Blind Watchmaker”. It is a bit too much to excerpt, but the fundamental point is that at the end of the day, the best way we can understand the bats experience is to walk into a room and flip on the light. They are no more concious of their echolocation mechanism than we are of processing visual information. No amount of description of how light falls on the retina to form images conveys what it is like to see, and no amount of description of how to construct sonar really gets at the experience of an echolocating animal.
The point is that we generally DON’T know how we view the world - we just do it.
We can have an idea of what they can percieve through echolocation, but any attempt to construct the experience is bound to be unnatural because we have to map it onto our ability to visualize. It’s probably best to just leave it at “the bat ‘sees’ through echolocation”, think about what kind of details they can actually make out that way, and imagine “seeing” a scene including only those details. Of course, that breaks down when you run into nuances that they can detect in the world that we can’t detect visually.
Questions of consciousness and the nature of experience get very deep very quickly. They make my head hurt too. You can find some helpful glosses in The Mind’s I, composed and arranged by Douglas Hofstadter and Daniel Dennett. They write “Nagel doesn’t want to know what it’s like for him to be a bat. He wants to know objectively what it is subjectively like.” If you too hope to achieve this inherently contradictory goal, jump right in.
Actually, bats pretty much see the world the way we do. Their vision is actually quite good. They just have the echolocation as an additional talent to help them avoid walls and branches while grabbing bugs or fruit.
Wow, thanks for the link. Interesting read that I think I’ll have to read a couple more times before I fully get his argument. Nice to know I’m not the first person to ask this question, even if my reasoning for asking is a little bit more naive than Mr. Nagel.
This is partially true. Fruit bats are not very good visually and cannot often catch mice in the wild. (Echolocation of course is useless for seeing mice among the leaf litter.)
But they will gladly eat if fed them in captivity.
One of my favoite Scientific American covers was one that showed about 20 different bat faces. It showed how varied the group is. They have a very wide range of capabilities and skills and tastes. Not all can use echolocation, for example, and rely entirely on sight.