I remember not really “getting” these illusions when I was a kid. I just didn’t find them interesting, it looked too straightforward.
The idea of a “2D screen inside our head” is not our natural intuition. Before learning about these things, I just felt that I simply percieve the environment around me. I don’t see a flat pixel grid in front of me when I walk around, I rather have a model of the environment that I continuously update and I percieve the objects “from where they are”, just like I feel leg pain as if it were “in my leg”, despite the fact that pain actually happens in the brain. I see objects where they are in the 3D model, not where they are on a virtual screen.
The screen and pixels analogy may be so prevalent in modern times because of the TV, photos or even earlier realistic paintings. But early art was not really realistic, which I think either shows they were
not skilled enough to draw realistic art with perspective distortions and shading, or
they didn’t think of vision the way we do today, they were more focusing on the objects and their prototypical shapes, rather than their position in the visual field and the “actual colors”.
The second explanation seems more plausible to me.
These illusions are only illusions if you take the “2D screen and pixels” view of vision. Now that view is also important for technological applications, and it’s also biologically relevant (retina cells are sort-of pixels), I’m just saying it’s not really an illusion against builtin intuition.
I don’t see a flat pixel grid when I walk around, either; I see a 3D scene (generally only where I’m currently looking; I mean, I can recall where things are when I’m not looking at them, but they’re not in my current visual model, that memory has to be stored elsewhere).
And yet, a lot of optical illusions work for me; because (as in the case of the illusion in this article) the drawing is close enough to what the reality looks like to fool my “scene reconstruction” module in my brain, and I reconstuct the relevant 3D scene when I look at it. Some optical illusions (such as this one ) work by being able to fool my scene reconstruction module in two different ways...
Somewhat related: I think we do have a 3D map of the environment even for things that we aren’t looking at at the moment. For example I feel as if I had a device in my brain that keeps track of which people are in which parts of the house right now (or where some emotionally-loaded objects are). I don’t have to exert conscious effort specifically for this.
Another thing: it’s interesting to think about why we can see dots and lines and shapes at all. By this I mean, why do these low-level things reach our conscious awareness? You aren’t consciously aware of your blood sugar level or hormone levels. You do feel a sort of aggregated well-being feeling consciously but the details don’t reach the conscious level. It’s a strange and bizarre thing to think about what vision could be like if our consciousness didn’t have access to dots and shapes and colors style low-level image data and we only “felt” the gist of it, for example by only feeling our current 3D model in some way. (It could be similar to blindsight.)
One answer could be that our vision is so complicated that the unconscious parts just can’t cope with it fully, they can’t analyze it sufficiently, and conscious processes (evolutionarily recent brain parts) need access to the basic “pixel-data” like things as well.
But again, maybe when we intentionally try to look at specific dots (as if looking at pixels, interpreting the visual field as a screen), we maybe aren’t really looking at the low-level input but rather a reconstruction. Maybe we are seeing lines, corners and other geometric primitives laid on top of one another, like an SVG image, not like a BMP image. Maybe we don’t really have conscious access to the low-level visual signals, we just have access to a reconstruction.
I don’t think neuroscience has found out these things already, but it should be possible to read off of connections of brain areas.
Somewhat related: I think we do have a 3D map of the environment even for things that we aren’t looking at at the moment.
I do not appear to have that—or, at least, I don’t get much use out of it if it’s in here. While I can keep track of who is where in the house, I do so more in the form of a list of Last Known Locations, not in any sort of map (2D or 3D).
Possibly related—I am notorious for getting lost easily while driving, and can get very badly turned around if I am merely a short distance away from where I should be. I tend to navigate by memorising a route from A to B, as a list of directions (turn left at the third corner, then it’s the fourth street on the right...) and then I get into trouble if I can’t follow that route. (Nowadays, I tend to lean heavily on GPS when going to new places).
I remember not really “getting” these illusions when I was a kid. I just didn’t find them interesting, it looked too straightforward.
The idea of a “2D screen inside our head” is not our natural intuition. Before learning about these things, I just felt that I simply percieve the environment around me. I don’t see a flat pixel grid in front of me when I walk around, I rather have a model of the environment that I continuously update and I percieve the objects “from where they are”, just like I feel leg pain as if it were “in my leg”, despite the fact that pain actually happens in the brain. I see objects where they are in the 3D model, not where they are on a virtual screen.
The screen and pixels analogy may be so prevalent in modern times because of the TV, photos or even earlier realistic paintings. But early art was not really realistic, which I think either shows they were
not skilled enough to draw realistic art with perspective distortions and shading, or
they didn’t think of vision the way we do today, they were more focusing on the objects and their prototypical shapes, rather than their position in the visual field and the “actual colors”.
The second explanation seems more plausible to me.
These illusions are only illusions if you take the “2D screen and pixels” view of vision. Now that view is also important for technological applications, and it’s also biologically relevant (retina cells are sort-of pixels), I’m just saying it’s not really an illusion against builtin intuition.
I don’t see a flat pixel grid when I walk around, either; I see a 3D scene (generally only where I’m currently looking; I mean, I can recall where things are when I’m not looking at them, but they’re not in my current visual model, that memory has to be stored elsewhere).
And yet, a lot of optical illusions work for me; because (as in the case of the illusion in this article) the drawing is close enough to what the reality looks like to fool my “scene reconstruction” module in my brain, and I reconstuct the relevant 3D scene when I look at it. Some optical illusions (such as this one ) work by being able to fool my scene reconstruction module in two different ways...
Somewhat related: I think we do have a 3D map of the environment even for things that we aren’t looking at at the moment. For example I feel as if I had a device in my brain that keeps track of which people are in which parts of the house right now (or where some emotionally-loaded objects are). I don’t have to exert conscious effort specifically for this.
Another thing: it’s interesting to think about why we can see dots and lines and shapes at all. By this I mean, why do these low-level things reach our conscious awareness? You aren’t consciously aware of your blood sugar level or hormone levels. You do feel a sort of aggregated well-being feeling consciously but the details don’t reach the conscious level. It’s a strange and bizarre thing to think about what vision could be like if our consciousness didn’t have access to dots and shapes and colors style low-level image data and we only “felt” the gist of it, for example by only feeling our current 3D model in some way. (It could be similar to blindsight.)
One answer could be that our vision is so complicated that the unconscious parts just can’t cope with it fully, they can’t analyze it sufficiently, and conscious processes (evolutionarily recent brain parts) need access to the basic “pixel-data” like things as well.
But again, maybe when we intentionally try to look at specific dots (as if looking at pixels, interpreting the visual field as a screen), we maybe aren’t really looking at the low-level input but rather a reconstruction. Maybe we are seeing lines, corners and other geometric primitives laid on top of one another, like an SVG image, not like a BMP image. Maybe we don’t really have conscious access to the low-level visual signals, we just have access to a reconstruction.
I don’t think neuroscience has found out these things already, but it should be possible to read off of connections of brain areas.
I do not appear to have that—or, at least, I don’t get much use out of it if it’s in here. While I can keep track of who is where in the house, I do so more in the form of a list of Last Known Locations, not in any sort of map (2D or 3D).
Possibly related—I am notorious for getting lost easily while driving, and can get very badly turned around if I am merely a short distance away from where I should be. I tend to navigate by memorising a route from A to B, as a list of directions (turn left at the third corner, then it’s the fourth street on the right...) and then I get into trouble if I can’t follow that route. (Nowadays, I tend to lean heavily on GPS when going to new places).