tilthat: TIL a philosophy riddle from 1688 was recently solved. If a man born blind can feel the differences between shapes such as spheres and cubes, could he, if given the ability, distinguish those objects by sight alone? In 2003 five people had their sight restored though surgery, and, no they could not.
nentuaby: I love when apparently Deep questions turn out to have clear empirical answers.
… they really can’t connect spacial awareness from touch to sight? Really?
I mean, apparently. The brain is so weird, it’s really really difficult to even imagine what it’s like to experience certain things that other people do. For example, sometimes people have their corpus callosum (the membrane between the hemispheres that allows them to communicate with each other) severed to prevent certain types of seizures, and afterwards they lose the ability to see “green men” as faces.
For reference, this is what a “green man” is:
https://acc-cdn.azureedge.net/mrlnop420media/0005503_green-man-wall-plaque.jpeg
Can you, who easily sees the face, really even understand what it would feel like to look at that image and not see a face?
I keep tryin but it’s lookin at me and it’s distracting
i think i can understand it by proxy, there are numerous optical illusions where your perception of something flips back and forth (like the duck-rabbit) and i’ve experienced seeing (and hearing) things that others laugh at or find interesting and it took me several days for it to finally click in the brain and from then on i couldn’t unsee it again.
deleted by creator
deleted by creator
Skill issue
Literally.
Sight is a combination of raw data input and interpretation of that data. It turns out that if you miss a critical window of learning early in life, you are almost certain to never learn how to interperet that data correctly even if you gain the ability to see. Many people who have gained sight after being blind from birth find it simply overwhelming and regret the medical intervention. Richard L. Gregory’s “Eye and Brain: The Psychology of Seeing” is a fascinating read on this topic. Even those with sight fail to interpretet things properly depending on their experience - for example, someone who lived in a dense forest all their life (where they never had the opportunity to see anything from a distance), is likely to think that the elephants are the size of ants if they are viewed from afar. A lot of brainpower goes into learning how to see in early life, and if you miss that, it’s over.
I wonder if this would extend to any attempt to augment human sight. Like, if we could implant new cells in someone’s eyes, identical in function to the ones that let them see colors, but these new cells detect, say, ultraviolet, would their brain be able to figure out what to do with the data?
Tweaking existing senses does work, but there’s limits. There’s people experimenting with stuff like implanting magnets in their fingers
Interesting question!
I could imagine it being difficult to conceptualize without the ability to visualize, but yeah, I find it hard to believe, too. Between cube and sphere, at the very least, I’d expect them to realize the pointy bits are probably the corners of the cube, not a flat surface.
What does a pointy bit look like to someone who has never seen one ? You have years of experience matching your visual input of the world around you with your tactile experiences, it’s easy to forgot how much of our basic knowledge is learned at a young age.
Sure, as I said, without the ability to visualize, this may be tricky. But I’m imagining this test as them being given enough time to think about it and feel the shapes and maybe even count the pointy bits. At the very least, I’d expect an educated guess that’s likely correct, if they’re only discerning sphere and cube. Of course, a lot depends on how these tests were performed.
How do you expect them to know what pointy bits even look like?
I don’t expect them to know. I’m saying, if they’re given time to think about it, I’d expect them to make an educated guess that’s likely correct.
Pointy bits feel thin, unlike the rest of these shapes. So, if they’re given only the sphere and the cube to feel, they could remember that the cube had 8 pointy bits, the sphere did not.
Of course, a lot depends on how these tests were performed and what “they could not” actually means.
You’re still assuming an ability to connect shapes to vision, even if what you’re assuming is the most basic connection. Keep in mind these people had absolutely nothing to base their visual experiences on. I’m sure that given a few minutes to play with the objects they’d begin to map their visual inputs to mental models, but at first, it’ll all look like abstract garbage
It’s not that they don’t have a sort of 3d model of a cube in their mind, it’s that their 3d model of a cube includes absolutely nothing visual, which is virtually impossible for us to even imagine
Though it’s virtually impossible to do, I like to imagine that their 3d object memories are analogous to data in a raw text file, representing every attribute of the object. However, they don’t have the software (vision) to visually render it, or vice versa turn visual objects into “data points in files”.
Since their brain is reading the file without visually rendering the object, the results of this experiment could be similar to us not recognizing a digital 3d object by reading the raw data without rendering it.
Or, on a musical note, similar to not recognizing a composition just by looking at the sheet music. Then, if you didn’t even know what music sounds like, it’d also be an even greater challenge to imagine any sound at all by just looking at sheet music, midi files (raw data or visualized), raw data of an audio file, or a visual spectrogram or waveform.
I actually felt like my pointy bits method was entirely disconnected from experience. Yeah, they see abstract garbage, but they’ll still see anomalies in this abstract garbage. And they were able to feel anomalies on the cube.
It does take some thinking to make a guess like that. And they may have still been completely overwhelmed with sight in general. And again, I don’t know what the methodology in these tests looked like. But yeah, just summarizing it as “they could not” seems entirely unhelpful.
Could they tell that there are eight pointy bits? A cube only has between four and seven pointy bits, visually, although the seventh pointy bit would be pointing at them, and I’m not convinced that someone who’s never seen before would be able to process what a corner looks like head on. If they could pick the items up to move them around, then they’d simply be able to tell by touch. Even if it was rotating on a turntable or something, they’d have no way to map the two dimensional image onto a three dimensional object in their mind. You can easily visualize how it looks to make one rotation of a cube, but if you’ve never visualized before, you’d have no way to translate what you’re seeing to the model you have in your mind.
100% agree on wanting more than just “they could not,” though
Also the whole bit with how eyes give a flattened 2D perspective from a distance of 3D objects they previously only has felt as 3D shapes directly in their hands
And there’s two of them, giving slightly different images (but without the whole circuitry developed at a young age that manages to calculate distances from the slight differences between the two images… hell, they might even lack the circuitry that corrects for the images being upside down, at that!).
You’re assuming their brains have had enough time and experience at that point to perceive the pointy color blob as an object