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Gene Therapy Causes Blind Woman To Grow New Fovea
Al writes "A woman with a rare, inherited form of blindness is now able to read, thanks to a gene therapy that caused a new fovea — the part of the retina that is most densely populated with photoreceptors — to grow in her eye. The patient suffers from Leber congenital amaurosis, meaning an abnormal protein makes her photoreceptors have a severely impaired sensitivity to light. She received the experimental treatment twelve months ago when physicians injected a gene encoding a functional copy of the protein into a small part of one eye — about eight-to-nine millimeters in diameter. Along with two other patients receiving the same treatment, her eyesight improved after just a few weeks. Now the physicians report that this patient seems to have developed a new fovea, exactly where she received the injection. Because the woman has been effectively blind since birth, the results suggest that the brain is able to adapt to new visual stimuli remarkably quickly."
Even with perfect eyesight, most visual cueing and a lot of filling in of detail is done by the brain, and not received by direct physical stimuli through the optic nerves. This can be seen in optical illusions meant to highlight or isolate certain aspects of visual construction.
If the brain does not receive visual stimuli as a child, then the visual centers never form properly, or at all. There is a certain time window, where the brain is plastic enough to learn the new input. After it has passed, then there are certain things the brain can not do, or do well - like learn new languages without an accent.
..........FULL STOP.
I would not be so sure.
I have strabism. More specifically, the kind of strabism where you can choose which eye you want to see with.
The bigger effect of this condition is a total lack of automatic brain-computed stereovision and depth. I must compute depth mentally, it's slightly less precise than the normal brain-computing. As a side effect, (most) optical illusions are ineffective on me.
I think the effects are very similar to her. The brain droped the useless parts a long time ago.
According to your grand-parent's linked study, I should have problems with overlapping squares. I do. The nearest one appears to have a border. I can't tell if it's a square with a border, a square behind another one, or something else. Here is the segmentation issue.
I also have problems griping some objects, walking on a non-flat surface or playing football. But I have no problem distinguishing objects from the environnement.
So, according to you, I should also have problems with overlapping windows on a screen. But no. I have no bugs, no troubles, etc.
If it's flat, there is no problem seeing it flat. I see forms, squares, borders etc., like everyone else. I know the concept of a window, the appearence of a window, and can mentally segment the screen according to it. I can do it because I already know the objects involved. With overlapping squares, I can't only because I don't already know them.
Do YOU see overlapping windows as if they were at different depths ? Woops.
Well, I have at least one advantage : flat films (or 3D video games) on flat screens appears as real and depthy than reality to me. No need for 3D glasses, they even reduce my visual ability by filtering out 2/3 of visible light.
Posted as an anonymous coward since I don't have a /. account yet.
Because the woman has been effectively blind since birth, the results suggest that the brain is able to adapt to new visual stimuli remarkably quickly.
We knew that already. People have been equipped with a camera and an actuator that "projects" an image through the tactile nerves on a patch of skin.... Those people similarly report being able to "see" using that hardware.
This leads me to believe that our brains are not hardwired to interpret visual information only on just the optical nerve. During the first few years, we learn what nerves are connected where. And our brains are flexible, and will be able to adapt to changes in what-connects-where.
In an experiment, a long time ago(*), a person was equipped with glasses that flipped the image in his eyes upside-down. In about two weeks he didn't notice the difference anymore. Also, learned skills, like skiing, were instantly possible with the re-wired visual hardware. Adapting to the original situation (no flipping glasses) was quicker than adapting to the flipping glasses.
(*) http://wearcam.org/tetherless/node4.html I intended "a long time ago" to mean something like "in the 19-seventies", turns out the original experiment dates back to 1896!