For a long time now, I have been trying to figure out how marijuana enables me to gain some access to vision, even though I am ordinarily totally blind with light perception. This involves translating the subjective experience into language others can understand, and pinpointing the difference between my experience with and without cannabinoids. Recently, I have arrived at the insight that while under the influence of cannabinoids, I am able to maintain momentum of my eye movements. When I move my eyes, they seem to obey the laws of Newtonian physics, in that if I build up the velocity of my eye movements, they will maintain that velocity. when I "push" or "throw" my eyes forward, the effort needed for that push or throw gives me information about my surroundings (i.e. white or reflective objects require very little effort, and my eyes slide across them with very little friction). When I am not under the influence of cannabinoids, I don't feel the kickback or reverberation when I move my eyes, so they feel numb and heavy and impossible to control. Currently, I am developing an interactive eye training program that gives me auditory feedback about my gaze direction. However, this is just a start, and I am very much thinking that some sort of wearable device is needed. I am starting to think that the function of this device would be to increase my ability to maintain this sense of momentum, without the influence of marijuana, but what would that look like on a practical level? Any thoughts are welcome.
A couple of issues.
There is always a problem trying to understand a first-hand experience (perceptual/cognitive/emotional) from a third-person perspective. So it's not clear to me what you mean by momentum. This is particularly important for nystagmus as the evidence is that how and what nystagmus sufferers feel, think, experience, can have a material effect on the nystagmus itself. So for example, if cannabinoids have the general effect of calming someone, this is likely to damp the nystagmus waveform (at least to some extent). But of course, in these circumstances, it may also alter the perception of what's going on, independent of any effect on the nystagmus.
For these reasons, trying to draw any conclusions without an actual recording of the nystagmus (ie an objective recording) is probably unwise.
Secondly, the balance of evidence is that we have little or no conscious perception of what our eyes are actually doing from moment to moment. Intramuscular signals from the extraocular muscles that move the eyes in the orbits are available to the central nervous system, but it remains unclear what these are used for - over the years there's been lots of suggestions (including suggestions about their role in nystagmus as it happens). But what you feel you are doing with your eyes, and what's actually happening to them, may be two very different things. Again a decent recording will help clarify things.
None of this is to say that your insights are unimportant, or that some form of biofeedback might not enable you to change the pattern of your nystagmus.
It was the most interesting lecture when my prof was talking about Nistagmus and congenital blinds. As far as I know, severe Nistagmus completely deformed the mussel and as a result it prevents the on-off period of the eye signals. I wonder have you ever try a device which can simulate the on-off period of the eyes. I am not an expert. However, when I was a psychology student, I thought that It can be useful.
Might want to take a look at this paper. There were some people looking at the influence of vibrotactile sensory substitution on nystagmus.
http://www.ncbi.nlm.nih.gov/pubmed/22350083
Hi Tasha,
Another great question...
What happens when you try and use your end point of gaze?
For example when you direct your eyes all the way to the right but turn your head all the way to the left?
Or when you look all the way up but tilt your chin all the way down?
The muscles that move the eyes usually change behaviour, and thus your eyes may jump around less, at the end points of gaze.
Stability is important for the retina to draw meaning from the world.
Constant movement can reduce and even obliterate the meaning of the information captured by the retina in a couple of ways...for example, text on a sign that is moving past a train window too fast to fixate is rendered unreadable, though there may be the impression that it was a sign with some text.
But, if the world is moving across your retina, with nystagmus as the main cause, then there is still usually a brief "pause" at the point where the pendulum of nystagmus turns and moves the other way (depending on the type of nystagmus that you experience). You may be able to find a way of turning your head away from the faster part of your eye movement, and thus reducing its effect, gain more ocular and thus more retinal stability and reach a threshold where the universal recognition units of your visual system is not overwhelmed by movement...and thus report no visual input.
How this seeing feels may be more linked with the way that with you tactility is much more phenomenologically important due to your sensory development not being modally dominated and orientated by visual input. Thus the tactile smoothness of white etc. Despite this tactile sensation, it may still be best to maintain the postural position that gives your eyes maximum stability, to keep the visual thresholds maximal...turn your whole body to "look" in a particular direction.
The medicinal cannabinoids could help in many different ways...maybe they also simply slow the movement of your eyes so you can see?
That is a good suggestion. Even when I move my head to the left, it's still difficult for me to control my eyes sufficiently so that they move all the way to the right. however, on Monday we are going to start doing data collection using eye tracking, and we'll get much more of a sense of the pattern of my nystagmus and how cannabinoids influence it. And hopefully we will be able to use that data to make changes to our eye movement training game that is designed to increase oculomotor control.