Comment by glenstein
1 day ago
>(As long as a pattern isn't fully contained within the blind spot regions of course)
There are dedicated optical illusion/explainers that give you the experience of the brain patching over the space with neutral background, even if there's something there, like a symbol or a star.
So if it's something featureless or continuous, like a wall of your room that's a solid color, or a sheet of college ruled paper, the pattern can just be continued.
That said I would stress there's limits to how much of that you can do just by pattern extrapolation as opposed to deriving images from distinct and specific information in a given region of the visual field. You have to know enough about a stretch of visual space to know that it's appropriate to spread a pattern over it, and that's the thing the blind spot doesn't know.
What’s interesting about that is that brain doesn’t actually give you much access to the sensor information directly, but gives an interpretation instead. There is a thing called Saccadic Suppression that blocks visual data processing for 50ms when eyes are moving, and the brain just backfills that missing data from the “next frame”. https://en.wikipedia.org/wiki/Saccadic_masking
Thanks, I had not heard of that one. As a recovering philosophy bro I love cataloging all of these peculiar artifacts of our visual experience. They turn out to matter quite a bit in some of the endless mind versus brain and mind versus matter debates. Off the top of my head:
- Blind spot where the optic nerve exits the eye
- Saccadic Suppression (new to me!)
- Panum's fusional area (how close the overlapping images of your eyes have to be to each other to get merged into a unified image)
- The wagon wheel effect
- trichromatic vision (obvious but important because it easily could have been different)
- The foveial field, the central part of vision that's extremely precise, while things increasingly further away from it are blurry
- specialization in peripheral vision, (eg better sensitivity to starlight, as well as better sensitivity to flickers and motion)
Add those all up and you get a bunch of specific but contingent properties of visual experience. Some people of a certain philosophical frame of mind like to imagine that we inhabit a kind of pure mental experience detached from the physical world, but even if you think you're making no assumptions about the empirical world, all of these contingent facts show up, which make a lot more sense as being the products of biological structure.