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Cells In the Retina Tile Like Puzzle Pieces
tim writes "Recent work at the Salk Institute in La Jolla, Calif. shows that cells in the retina sample visual space like a multi-layered jigsaw puzzle. High resolution measurements of light response reveal that individual cells have irregular shapes, but together their shapes coordinate to tightly cover visual space. This type of large scale, exquisite coordination could be a general organizing principle of the brain, but no one has seen it previously because technical obstacles typically prevent recording from large cell populations." Here's a link to full paper.
Fits together like puzzle pieces? I think the dames call it "Tessalation"
http://en.wikipedia.org/wiki/Tessellation
Often wrong but never in doubt.
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They talk about an exquisite coordination that is finely tuned to prevent blind spots while avoiding overlap.
Perhaps it is more like cells with random variation simply growing outward until reaching a neighboring cell at which point some chemical signaling occurs to establish a mutual border.
Or maybe a time lapse of cell cultures would show an ever changing chemical war fighting over the borders like neighboring corals do.
A system like this should provide maximal coverage with minimal overlap with no exquisite coordination beyond the individual cells.
That sounds so complex, it's almost as if it could only have been created by god. ...
(I'm kidding. Please be gentle!)
What is this?
Not only is there a link directly to the article, but there is a link to the actual paper!?
I think the breakthrough here is not that the cells themselves fit together but that the individual fields they each sense are coordinated. Like one cell type senses a field that is circle shaped, the one right next to it, if it sensed a circle, would have overlap and would cause imaging problems, instead the cell right next to it senses a crescent shape, fitting with the one next to it to avoid overlap.
FTA
These regions fit together like pieces of a puzzle, preventing "blind spot" and excessive overlap that could blur our perception of the world.
How the cells come together is regulated but it still isn't like pixels, the junctions between the cells are not a perfect grid, there are irregularities. The cells compensate for that. I haven't read in depth but that seems to be the gist.
In spanish that eye disease is called cataratas, and that word can be translated too to waterfalls. When read about a puzzle in the eye, tetris was my 1st idea with that in mind.
How the cells come together is regulated but it still isn't like pixels, the junctions between the cells are not a perfect grid, there are irregularities. The cells compensate for that. I haven't read in depth but that seems to be the gist.
I know you're correct without reading the article, since I've seen the grid of my own optic cells myself in all its organic beauty -- the term 'grid' is still useful if you don't assume straight Cartesian lines separating rows and columns but rather swooping arcs and spirals -- while tripping balls.
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Will this type of thing be of any use in fixing that problem people have with color?
I hate to say it but the fact that our vision system has complete coverage over the visual field is so f**ing obvious and has been shown so often before that there should be little need to do yet more research on that subject.
What is really valuable and novel about this research?
you're eye is just organically attracted, narcissistically, to patterns that resemble itself
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Like one cell type senses a field that is circle shaped, the one right next to it, if it sensed a circle, would have overlap and would cause imaging problems, instead the cell right next to it senses a crescent shape, fitting with the one next to it to avoid overlap.
It looks to me more like a case of "random shaped squishy things squish together with no gaps". I'd say you have cause and effect mixed a little here - the crescent-sensing cells aren't crescent-sensing because they go "there's a circle next to me so I ought to check for crescents to improve the accuracy of the retina as a whole". They go "I'm squished into a crescent shape, so I'll naturally give a stand-out signal when a light pattern the same shape as me shines on me". The interesting question is how the shape of the cell is encoded into the output signal...
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I got grids of octarine elephants on a sphere rotating around a giant octarine elephant which was rotating the other way, myself.
:)
I'd always wondered about the tiny specks you can see when you look at a solid, bright background for a while, turns out they're white blood cells moving through the vessels that supply your retina. Cool, huh?
Rampant carbon sequestration destroyed the Dinosaurs' tropical paradise. I'm here to help repair the damage.