Showing posts with label 3D. Show all posts
Showing posts with label 3D. Show all posts

Saturday, January 11, 2014

Session 66: Inferring anaglyph depth through touch, definitely not dyslexic and soupy air

Our senses are inferential by nature. This means that our senses pick up on different kinds of stimuli and the brain infers a meaningful percept. Probably there's an objective reality out there but that is not what we perceive. Colors don't really exist in nature for instance, they are just distinct wave lengths of light interpreted by our brains as color. Probably because it is highly useful in finding food and recognizing predators.

If a tree falls in the forest and no one is there to hear it, does it still make a sound? No, because sound is something constructed by our brains by using the pressure wave input received by the cochlea. The waves are still there but it doesn't make any sound if there's no brain to generate the perception of sound.

You get the idea. The brain picks up on different kinds of signals through our senses and assembles one consistent subjective percept of our environment. Now wrap your brain around the following anecdote.

Inferring anaglyph depth through touch
Tranaglyphs (transparent anaglyph) are transparent plastic cards used in combination with red green anaglyph glasses. One of the cards depicts a red image and the other a complementary green image. If you combine them with the glasses a normally sighted person would perceive one single 3D image.


I couldn't find the one we used in the office online but it is similar. It was a boy with two balloons, one in each hand. He's just been standing there annoying me over the last three years. By now I can fuse him and he's single which is great. (I just realized how wrong that sounds.) I'm not getting any luster glow but I can move my eyes to keep him single as my therapist moves the cards in the holder. So far, so good. This time we tried something new. She said 'Try to touch the little guy's head with your finger and stop where you feel he should be'. It sounded like a pretty absurd idea. Obviously he's right there on the bloody card. I did it and I stopped where I felt he should have been if he wasn't on the card. It's a weird feeling. It feels like something is not adding up. Then she said 'Now try touching one of the balloons'. I did and I immediately knew that the balloons were supposed to be farther away then the little boy. To my surprise it was the correct answer! I can hack my vision and infer depth in stereograms by trying to touch the portrayed objects in thin air. The interaction of my senses is telling my brain something about the depth I should be seeing but I'm not SEEING it. I must be getting close. The position of my eyes and their movements must be getting more integrated with the rest of my body and its movements. During my last check-up I also correctly guessed the answer to a stereogram. Maybe the back door is being opened and I'm in for a serious brain fart in the near future. Probably I should just relax and let biology do its thing.

Added notes: Apparently merely intending to interact or to reach out to a target can change our perception. To learn more about the complex interaction between action and perception see: http://en.wikipedia.org/wiki/Two-streams_hypothesis. The dorsal 'where' stream often bursts the ventral 'what' stream its bubble when preparing to interact with a target to make our perception more suitable for that action. It's funny how this knowledge becomes a lot more real with first hand experience.

Definitely not dyslexic
Most people associate reading difficulties with the word 'dyslexia' whatever that means. Dyslexia must have good marketing. I looked it up on the internet and there's all kinds of vague and inconsistent definitions. Reading is a very complex process so I'm sure a lot can go wrong. The thing is to figure out what is keeping that particular person from reading adequately. The only book I have read somewhat covering the subject beyond binocular vision is 'The woman who changed her brain'. Binocular reading problems were called 'motor symbol sequencing deficits' and was the most common reading bully. The other two were a Broca area deficit (auditory speech) and a symbol recognition deficit. I figured if dyslexia did not refer to eye teaming problems it would probably refer to the inability to recognize letters quickly and infer meaning. After doing that internet search, I'm not so sure anymore. The paragraph should probably be called 'definitely not symbol recognition deficient'.

Here's how I know I don't have a symbol recognition deficit. My Vision Therapist uses a customized computer program enabling her to test certain things and then send me downloadable exercises based on those tests. All of them partly in red and partly in green of course to make them anaglyph compatible. Eccentric circles are a classic but lately we've been mixing it up with more game like exercises. Nothing too exciting but I have a tolerance for boring stuff as long as it serves a purpose. One of the most recent exercises is one that tests and trains 'visual capturing and memory'. The program displays a number of symbols during a fraction of a second and then you have to reproduce it by memory. Some people apparently find this hard even for very recognizable words. When doing this exercise with actual words my tests scores are impeccable. I think this must be one of the ways I compensated for unstable eye movements. You don't get much time or much stable vision so you have to infer a lot from what you do get to see when reading.

Interestingly the program allows you to do the exact same exercise with random red green combinations of five unusual symbols (cross, star, square, rectangle, circle). Then you have to reproduce them by clicking on the right symbols in the right order. Man, do I suck at those. Goes to show how trained we get at recognizing words. I've been doing that exercise for a while now but improvement is slow. I think I can only really focus on three or four of those symbols at once and try to make a quick saccade to see the fifth. But there's no time! I should be trying to get more of them into my visual field so I can capture them at once.

As far as actual reading is concerned, my new year's resolution has been to try do more bar reading. It's a crucial exercise for getting over the residual Convergence Insufficiency and improve fine eye motor skills and ultimately reading skills. I'm putting in the time and the work. Results will follow. All these basic vision skills I've been working on for so long are coming together. I'm excited to be so close to improved reading.



Soupy air
In summer, when cars are being punished by extreme temperatures you can see the heat waves bouncing off their roofs. It seems that's a pretty common perception  so I will use it to explain the feeling. This time of year it seems unlikely that heat has anything to do with it though. During recent weeks I had a couple of moments of 'soupy air'. It's hard to describe but it's like those heat waves are bouncing off of people or things for brief moments. Something that seems to trigger it are stripes. Striped shirts, floor radiators and even train tracks... Maybe it's just a coincidence and the lines have nothing to do with it. But that must be one huge coincidence then. I don't know what to make of it... Glimpses of depth? Palpable space? Perhaps.

Friday, September 21, 2012

Session 41

Life after the zero degree angle. Since now I have a zero degree angle (aligned eyes) most of the time I can see a clear distinction between the time I am pointing my eyes correctly and the time I'm not. This is the 'advantage' of having double vision as opposed to suppressing the second image. Obviously I try to point my eyes properly as much as possible. The best way to achieve this is to sleep well, rest and not overdo anything. As is true for all strabismics things get harder by the end of the day. It's very important I try to see well without pushing it. Aim for quality, not for quantity. At first it's better to drive well than fast. After you can drive well and fast (but not too fast:)). Once your skills reach a certain level, you can apply them on the road. So whenever I'm awake, I have to take care of my eyes. This requires a lot of discipline and self control because virtually every activity involves eye sight. I can live with a limitation of freedom that serves a higher purpose (being healthy 3D vision) that is worth doing it for.

I don't have much to say about todays session... Trying to improve and extend existing and upcoming skills will take more time and work so we are just doing that. Home work: PC exercises, a wooden wheatstone stereoscope and a prism flipper to use while reading.

Thursday, August 30, 2012

The Fun Theory: free anti-suppression solitaire

Most cross-eyed people suppress the image of their inferior eye or alternate between eyes. The trick is to learn how to use them both at the same time in a correct way without suppressing either one or the other. One of the ways to do this is with a the red green 3D glasses and red green computer images so you have to use both eyes at the same time to see everything displayed on the screen. Most exercises like this are rather boring, you train the ability but it's not much fun. Another blog I found proposes a red green card game making it rather fun to practice using both eyes together.

http://squintyjosh.blogspot.com/2011/01/free-anti-suppression-solitaire.html

With the 3D glasses you will need both eyes, otherwise you are not seeing half of your game haha. I like this kind of creative and fun solutions to promote behavioral changes. It reminds me of the VW fun theory :)



It also coincided with a TED Talk I saw on using games to recover from brain injury.



Saturday, July 28, 2012

How a movie changed one man's vision forever (BBC)

Bruce Bridgeman lived with a flat view of the world, until a trip to the cinema unexpectedly rewired his brain to see the world in 3D.

On 16 February this year, Bridgeman went to the theatre with his wife to see Martin Scorsese’s 3D family adventure. Like everyone else, he paid a surcharge for a pair of glasses, despite thinking they would be a complete waste of money. Bridgeman, a 67-year-old neuroscientist at the University of California in Santa Cruz, grew up nearly stereoblind, that is, without true perception of depth. "When w'd go out and people would look up and start discussing some bird in the tree, I would still be looking for the bird when they were finished," he says. "For everyone else, the bird jumped out. But to me, it was just part of the background."

All that changed when the lights went down and the previews finished. Almost as soon as he began to watch the film, the characters leapt from the screen in a way he had never experienced. “It was just literally like a whole new dimension of sight. Exciting,” says Bridgeman.

Full BBC Report: http://www.bbc.com/future/story/20120719-awoken-from-a-2d-world