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Explaining my work

Dr. Greek believes the topic is too complex to have an online discussion. I disagree. As Richard Feynman used to say, you really show you understand something if you can explain it to the average person. So far he has failed.   

Instead of offering explanations Dr. Greek repeatedly asks the readers to read his book.  I will ask you to do the same.  In my eyes, the text is a never-ending collection of half-truths and out-of context citations interrupted by a mediocre presentation of dynamical systems and chaos. 

If anyone develops any insights after reading his book that you can explain to the average person, I ask you share with us here.  

As for my research, Dr. Greek writes:

When he says “the restoration of sensory function” he is promising (explicitly in my opinion although some would claim it is only implied) the restoration of sensory function in humans.

Yes, I am explicitly referring to the restoration of function in humans!  

This is not far fetched science fiction. This is happening as we speak, right now, across the world, thanks to the knowledge gathered by the use of animals in research by many talented and dedicated colleagues.

Let me explain.

Blindness may occur due to retinal diseases that affect how the eye captures light and converts it into electrical signals that are sent to the brain.  One such case is retinitis pigmentosa, where patients lose their vision due to the death of photoreceptors (the cells that translate light into electrical signals). Blindness may also occur when the fibers carrying information from the eyes to the brain are severed, such as when the resection a tumor also happened to damage the optic nerve carrying visual information from the eye to the brain.

In the first case, scientists are exploring the notion of replacing the dead photoreceptors with electronics. The basic idea is that an electronic chip in the back of the eye will capture the light  (in a similar way a video camera does) and use the information to stimulate electrically the remaining cells in the retina in order to restore vision. There are multiple groups working on such retinal prosthesis that are now making their way now to clinical trials (see videos below).

In the second case, when the optic nerve is damaged, one cannot stimulate the retina directly because the information from the retina cannot reach the brain anyway.  Instead, scientists have demonstrated that direct electrical stimulation of early visual cortex in blind subjects can evoke visual percepts (so called phosphenes). To understand how to stimulate these neurons, however, we must first know how these neurons are organized and what features of the image they normally respond to.  Only then, an external camera and image processing can be used to replace the function of the eye to feed this information directly to the cortical structures via electrical stimulation.

Star Trek fans may recognize such device as the one Luitenent Commander Geordi La Forge wears. What many people fail to realize, and also evident is Dr. Greek skepticism about my statement, is that the feasibility of such a system has already been demonstrated  and we are closer to achieving this goal than the average person believes.

Thus, the story is indeed very simple: basic science about how the early visual system works is, among other things, helping us develop prosthesis that are restoring vision in blind patients.  To satisfy Dr. Greek, I assert here that the organization of the retina and early visual pathways of old-world monkeys and humans are, for all practical purposes, identical. Similar technologies based on our knowledge of motor cortex are also being used to restore movement and develop artificial limbs that can be controlled directly by the patients’ brain.

None of this work could be possible without the use of animals in research.

I understand and respect the position of those that oppose animal research based on ethical grounds. But I dispute the assertion of Dr. Greek and other animal right activists that the work amounts to “scientific fraud”. This is just patently false.

Science works.  It truly does.

If Dr. Greek wants to enlighten us as to the future of medical research he should start his own research program and lead the way forward. I wish I could offer my opinion of his research, but unfortunately he seems to have published nothing at all.

For those of you that want to learn more about prosthesis, I invite you to watch the following videos and read these articles, as well as to visit the NINDS page on neural interfaces program.




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