Thread: Bionic Eye

Artificial eyes would be huge in the medical field for repairing lost sight, considering you can't replace old eyes with surgically transplanted new ones (correct me if I'm wrong).

There was a report I watched years ago of a surgeon who had a port placed in the back of his neck that intercepted the signals that went to his right arm, and allowed him to interface with a computer to conduct a simple surgery overseas by manipulating a robotic arm. I can't seem to find the link to it anywhere, but I'm inclined to believe it was genuine.

But back to optics, I'd really like to see to this new bionic eye work out. I imagine that different kinds could be made to be switched out for the appropriate situations. To be able to see on the lower end of the infrared spectrum, for example, would be rather incredible for human beings. That alone would revolutionize the way we interact. I can imagine it would be much harder to run from law enforcement as well, heh. No more hiding.

Originally Posted by Invader

But back to optics, I'd really like to see to this new bionic eye work out. I imagine that different kinds could be made to be switched out for the appropriate situations. To be able to see on the lower end of the infrared spectrum, for example, would be rather incredible for human beings. That alone would revolutionize the way we interact. I can imagine it would be much harder to run from law enforcement as well, heh. No more hiding.

Man, that is a GREAT thought. That's what I mean when I say "It's interesting to see what is slowly becoming of us". The more technology advances, the more I think that soon enough, we'll have some new "functions" available to us.

Hey makes me wonder... do you know if wireless data has any light in it? or is it only vibrations? or perhaps something else? It just got me thinking that..what if we could perceive all the data transmitted through radio and beyond waves. That way we could broadcast an entire library of info and access it at will, anytime, anywhere?

Anyway...just speculating! Thanks for you feedback

I wonder how this works on a neural level.

The brain is immensely plastic. I wonder to what extent you can just 'plug and play' with these things. They once had some experimenters wear upside-down glasses. After a few weeks their vision had turned upside down so that they could see normally through the glasses but upside-down without.

Originally Posted by Xei

I wonder to what extent you can just 'plug and play' with these things.

The critical period for developing visual acuity seems to end at age 7 or 8.

There are some people born who are born with congenital cataracts that render them effectively blind from birth. When these people have their vision surgically restored in adulthood, they have historically been unable to do much at all with their new sense of vision. Additionally, animals experimentally fitted with opaque contact lenses during development remain blind when these lenses are removed in adulthood. However, if vision is allowed to develop normally before being lost and then subsequently restored, vision will be normal, and if congenital blindness is corrected before the critical period ends, some visual acuity can be salvaged.

Regarding how the "bionic eye" works on a neural level; it should be a theoretically simple matter of feeding constant, graded electrical charges (more light = more negative charge) to the appropriate retinal neurons (probably the bipolar or ganglion cells, since presumably the cones/rods wouldn't be working in the blind patient; additionally, feeding directly to the optic nerve probably wouldn't work because perception of location depends on which retinal neurons are firing) and letting the nervous system take care of the rest. Of course this is easier said than done, and in practice this would be an extremely complex endeavor. Also, certain effects such as contrast/edge enhancement and color perception would likely not be achieved - certainly not in this current, relatively primitive prototype anyway.

Interesting... so the the brain undergoes a period of superplasticity in childhood?

How come the upside-down glasses experiment worked? That seems to require pretty significant rewiring.

http://www.youtube.com/watch?v=39co0zKbQAQ

Originally Posted by Xei

Interesting... so the the brain undergoes a period of superplasticity in childhood?

Right. This critical period of plasticity reaches far beyond visual development, as well. For example, you've probably heard that languages are most easily learned during early childhood. The critical periods vary depending on what we're talking about - as another example, the critical period for developing the incest-avoidance response appears to be within the first 2 years - but in terms of overall plasticity, the brain is pretty stable (compared to the early years) by adolescence. See this Wiki article for a little further reading.

Originally Posted by Xei

How come the upside-down glasses experiment worked? That seems to require pretty significant rewiring.

A lot of the visual development in childhood has to do with building up the visual areas of the brain in terms of both overall mass and neural connections. Once this area has been built up, I imagine it would be a relatively simple matter to "re-wire" these areas to account for interacting with an inverted world. The brain does remain highly plastic throughout life, just not to the degree that it is in early childhood, at which time it can be (and frequently is) likened to a sort of developmental sponge.

Extremely interesting. Do you know some theories about the evolutionary advantages? I wonder if it is theoretically possible to chemically induce superplasticity in an adult. I wonder further if that is a good or terrible idea.

I'm not aware of any existing theories, no. I could speculate on a few myself, but I think that this might be a good time to make a more general point regarding evolution (as long as High Hunter doesn't mind a mild thread-jack ).

Why do we take 9 months to develop in the womb? Additionally, why do we typically only produce one child at a time, and why do we not reach sexual maturity for over a decade? Wouldn't it be extremely advantageous if we had a gestation period of just a few days, produced dozens of offspring at once, and were ready to produce another generation of offspring after only a few weeks?

Of course it would. However, an important feature of natural selection to remember is that it does not result in an arms race - it leads to the most optimal configuration for an organism. Consider the above questions. Human beings are incredibly complex. To produce a fully functional human baby (nevermind several dozen) in just a few days would require the mother to consume an unholy amount of calories. Even the most dedicated bodybuilders don't use more than perhaps 6000-7000 kCal per day. The other questions have similar problems (it's hard enough getting one baby through the birth canal, let alone 30!).

The take home point here is that everything comes at a price. While it may be advantageous in some respects for humans to retain a super-plastic brain throughout the lifespan, this would come at costs that would ultimately outweigh the benefits (energy requirements being only the most obvious cost - we probably cannot even foresee all of the limitations). The most optimal solution, therefore, is to have a critical period of development during early childhood, while everything is new and must be learned for the first time. After things like the senses, language abilities, basic social skills, etc. are initially learned, the demands don't really change much if at all later in life (or at least, they didn't in the environment of evolutionary adaptedness), so the most optimal solution is to switch off the super-plasticity at this time.

WHAT IS THIS?! A thread jack??

Mouhahahaha, DuB keep it coming man.. Your content is always appreciated, plus it's pretty much on topic!

Referring to the "plasticity" of the infant brain is a little misleading, though. Much of the mechanism of this plasticity, if I recall correctly, is an overabundance of neurons. As we learn the basics (vision, speech, motor control, etc), those neurons which are used thrive while others die off, leaving behind the patterns and structures that let us operate in the world. Preserving that plasticity would mean never learning: persistent infancy.

Perhaps in the case of those who 'missed' a stage of development, like the cataract babies, a stem cell therapy could be devised. It might even require removing brain tissue and replacing it with stem cells, which could then mimic nearby neurons while hopefully remaining plastic enough to adapt to visual stimuli. I believe stem cell research is underway for dementia and brain damage, but to my knowledge there's no working therapy yet (anyone know better?).

Posthuman applications might involve dosing stem cells and cramming, say, Mandarin, but it's hard to imagine skills valuable enough to merit elective brain surgery. Perhaps if longevity reaches absurd proportions, it would be worthwhile for a healthy, active 100 year old to go plastic and cram current paradigms.

Originally Posted by Taosaur

Referring to the "plasticity" of the infant brain is a little misleading, though. Much of the mechanism of this plasticity, if I recall correctly, is an overabundance of neurons. As we learn the basics (vision, speech, motor control, etc), those neurons which are used thrive while others die off, leaving behind the patterns and structures that let us operate in the world.

Right you are. I had forgotten about that .

Here's some more info,

http://www.abc.net.au/science/news/stories/s653099.htm

The device consists of a silicon chip inserted into the eye, which is designed to act like a retina — receiving images captured by a pair of glasses worn by the user.

"It is a silicon chip which decodes the radio signals and delivers the stimulations," Mr Suaning explained. The chip sends messages to the retinal ganglion cells through small wires.

The unit then breaks down the image into pixels and sends the information, one pixel at a time, to the silicon chip, which then reconstructs the image, said Mr Suaning.

"We broadcast data into the body using radio waves," he explained. "It's like a radio station that only has a range of 25 millimetres."

and some wiki info as well;

http://en.wikipedia.org/wiki/Visual_prosthesis