Visual experiment: need help devising!

[dslc1000]

I want to devise an experiment which has the following purpose:

To determine whether or not photons of light are being emitted at the retina during R.E.M. sleep (i.e. dreaming). I'm thinking of using photographic film, or some other photochemical material, which I would place over the cornea - part directly over pupil - of the subject (with their permission of course). Can anyone help me devise such an experiment?

 

Some possible difficulties I can think of:

(i) the rapid eye movement could make it difficult to keep the film in place.

(ii) photographic film might need to be very sensitive.

 

One of my textbooks states: "The truth is that retinas don't radiate light" ('Neuroscience: Exploring the Brain' - 2nd Edition; Bear, Connors & Paradiso; p. 367). I suspect that this hasn't been confirmed however, and that they were just presuming this to be the case. Having said that, if anyone can tell me definitively that light can not be emitted by the molecules of retinal in the photoreceptors, and refer me to literature to back up their assertion, I would appreciate if they did so - to save me wasting my time. Thanks!

[Pinch Paxton]

Hmmm, well, it is a bit pointless for light to be used for dreaming. You see a tree because the light is shaped like a tree. Your theoretical light would have to be shaped like a tree as well, but if the brain could shape light like a tree, an emit it onto the cornea, then it could also generate the image directly inside the brain, so it wouldn't need to put it on the cornea. You can see that only the final product is required. Worth testing though I suppose. Someone should try it out.

[Neurocomp2003]

I doubt the experiment would be feasible because of REM, keeping the photographic film would require one of two thigns gluing it to the cornea or using a fixation apparatus which would involve and external (eye being open) or internal may have dangerous effects in cutting tissue around the eyebal.

 

...plus you wouldn't want hte film to be grown into the eye(as contact wearers are always told to be cautious of)

 

and what type of photons are you theoretically trying to detect...because eye doctors can see the retina but i don't think thats the photons your looking for....are you looking for a reflective image of what people are dreaming for?

[dslc1000]

Hi Pinch (if you don't mind me calling you that). In one of my previous threads (HERE), I explained why I believe that photons of light are actually required for vision to take place. Now, as far as I know, no light actually reaches the inside of the brain, and it doesn't have a means of generating light that I know of either. One of the things I want to determine in this experiment is whether or not the molecules of retinal in the photoreceptors at the back of the eye have this ability. It is already known that they absorb photons of light; I am suggesting that they might also emit it as well.

The devising of the experiment is encouraged by my discovery three days ago that there are actually nerves which travel from inside the brain to the retina. THIS article (section: 5. Centrifugal fibers in mammalian retinas) explains that centrifugal fibers (coming from inside the brain) have been traced as far as the inner nuclear layer of the retina, where they disappear. This is the layer directly beside the photoreceptors themselves. And note: the fibers disappear here; they don't necessarily end here.

This is mainly speculation as of yet, but I certainly think its worth pursuing.

 

neurocomp2003: Yeah, I suspect that your doubts are well-founded. And, yeah, damaging tissue is another thing I'm afraid of.

and what type of photons are you theoretically trying to detect...because eye doctors can see the retina but i don't think thats the photons your looking for....are you looking for a reflective image of what people are dreaming for?

To answer your question (I think), I want to test the hypothesis that this (the retina and the rest of eyeball) is: (i) where the images we see while dreaming are actually constructed, and (ii) where we 'actually see' when dreaming.

[Neurocomp2003]

cool, my belief is the good old centers of spatial imagery...PC and OL regions and PFC. There obviously is high feedback frmo PC and OL to the eyeball/retinal regions(which would make the effect seem like it shoudl be the eyeball region which is why it would be active) but your theory is still possible.

 

WIth my theory, the retinal regions of activity(like eye movement etc) are caused by the feedbacks from the activity in PC/OL/PFC.

[Skye]

Why not use retinal itself, rather than peoples eyeballs? I'm sure it would lead to less horror.

[Neurocomp2003]

...would you want someone to open up your eyeball? or pull it out to get to the retina? Remember alot of experience you sign waivers so the experimenters don't get the blame

[dslc1000]

Good point Skye. It would seem to make alot of sense to test whether or not retinal has photon-emitting capabilities in vitro rather than in vivo. Unfortunately I don't have access to the apparatus which would enable me to do this.

 

I'm not sure if you're asking me or skye that question Neurocomp2003, but I can assure I have no intention of doing either of those things.

 

Maybe I'll try simply lifting up people's eyelids, and looking at their pupils myself. I don't know if many people would be willing subjects for that experiment however, especially if there was a risk they could be woken up. I also hope that actually lifting the eyelids - and thereby allowing any external light to enter the eye - would not disrupt any photon-emitting activity that might be going on at the retina (a dark room would quite possibly help I think).