Monday, April 22, 2013

An amateur's golf quest sheds light on how we learn: some vision therapy related thoughts

I'm working on some more technical vision nerdy posts for the near future but meanwhile I came accross an interesting Time Magazine article.

A 30 year old commercial photographer named Dan McLaughlin living in Portland, Ore., quit his job and decided to make some changes. He committed himself to a goal. Someday he'd be playing the Masters Golf Tournament, but until then he had barely swung a club in his life. Since his 30th-birthday he has logged about 4000 hours of practice time and has lowered his 'handicap'. Since April 2010, he has worked on his game six days a week, living off savings and some wise stock picks and by renting out the house he bought five years ago. Right now, he's better than 85% of the male American golfing public.

For Robert Bjork, psychology professor at UCLA, McLaughlin is a lab rat in the human form. He's testing a popular theory developed by Anders Ericsson that, on average, 10000 hours of deliberate, efficient practice can produce international expertise in fields like chess, dance and swimming. Ericsson based his theory on the careers of professional musicians who tended to start their 10000 hours before they could read. A 30-year-old starting from scratch was new to him. "I've never heard of anyone else committing to it like this," says Ericsson, who has advised Mc Laughlin. "It's like Dan is going into mental space, seeing what's possible."

McLaughlin knows it's a long shot. "I couldn't imagine a more frustrating pursuit," he says during a practice round. Dan's progress is amazing but as you start pushing the extreme of the distribution curve it gets increasingly difficult. Whatever McLaughlin's odds, academics are watching him closely. On the annual Interdisciplinary Conference on Human Performance - a gathering of the country's top learning and memory researchers- the Dan Plan was a hot topic. "It has much grander implications than golf", says Mark Guadagnoli, a kinesiology professor at the University of Nevada at Las Vegas.

McLaughlin might be a case study for coaches, teachers and anyone interested in how to learn faster and remember better, because his training routine incorporates interleaving. Pupils often receive the message that blocked practice, or repeating a task over and over, will improve performance: hit 100 drives, shoot 100 free throws, read a chapter three times. But on the golf course, you don't get 20 tries on the tee. Bjork's hunch is that interleaving, or mixing things up, is the right way to train, so McLaughlin is continually switching up clubs and altering targets. As alluring as the 10000 hour rule has become, the number of hours you put in might not be as important as what you do with them. Bjork scans the other golfers on the range pounding ball after ball and pities them. "Ninety-five percent of the people here are doing it wrong," he says.

 Studies show that interleaving works. Novice putters who mix practice distance perform better on follow-up tests. Variety helps not just motor learning; Bjork has shown in experiments that interleaving improves recall too. In one study, college students learned art styles better by interleaving various painters. ...  

"What we're talking about is finding the biological sweet spot," says Guadagnoli. Interleaving gives the brain a better workout because mixing tasks provides just enough stress to trigger the release of a hormone called corticotropinreleasing factor (CRF) in the hippocampus, the brain area central to memory and learning. CRF strengthens synapses. For McLaughlin, all this just stressful-enough slogging is paying off. "The fun of this isn't playing the rounds," he says between shots. "It's experiencing the payoff from practice. You work on something, and it starts to click. Those aha moments are gold."

This article interested me for a couple of reasons:
1. Insane commitment. 
If you want to learn something you never learnt before and some people think is impossible, you must indeed go to that mental place and 'see' what's possible. My first mental space of this kind in Vision Therapy was Fixing my gaze but the longer I pursue this alley, the more science and real life experience are proving me visual recovery is possible.

2. 10 000 hour rule
I like numbers, or at least I like quantifying things, in order to measure progress. In case of visual rehabilitation  the 10000 hour rule can be used differently in my opinion. After a life time of visual regression accumulating into three years of debilitating double vision and some counterproductive strabismus surgeries, I was ready to give up. In total despair I did one last attempt to find a solution and I found it. I started to understand what had gone wrong for all these years and started putting vision improvement first as much as I could. You are seeing every waking hour, but you aren't training your vision every waking hour. But even if you are not training, as long as you don't visually over-train by obsessively killing yourself over study loads you can start to allow visual improvement. If you are having double vision 24/7 you ARE doing vision training just by being awake. The only time you are comfortable is when your eyes are closed. The trick is not to over-train  Not kill improvement by wanting too much or let the environment push you into situations that jeopardize your goal. This is hard. Everyone and everything can be the enemy. Coming from absolute binocular vision rock bottom and assuming one tries to see (but doesn't manage to even see a single image for the first 20 months) for 10 hours a day, I estimate it will take me a 1000 days of nearly uncompromising pursuit of proper binocular vision in order for me to achieve some stereovision. This comes down to two years and nine months. Interestingly enough that checks out with my former intuitive estimations. Earlier I expected to start seeing some single imagery in September 2012 and that prediction came true. I'm curious whether this next prediction will come true. I admit I just 'made up' that 10 hour assumption and might be considered arbitrary, but I didn't make it up in advance so it would fit. Well, we'll see in a few months, won't we?

3. Interleaving
It's also one of the basic principles in VT. If you monotonously do one exercise or train one aspect of vision you won't build a diverse repertoire of visual skills you need in life. The goal is a strong and solid visual system that can easily adapt to any situation or task. In fact, it's just a fact of nature as far as I can tell... Diversity is stronger than mono-culture  It's also yet another indication of why having your eye sight checked with a Snellen chart at a distance of 10 meters without further testing of visual skills is just idiotic.

4. Aha moments
It's true that this whole process of vision improvement isn't exactly fun. Acquiring vision skills everyone takes for granted or as the article puts it, everyone has started their 10000 hours of training for before they could even read, isn't much of a blast. In fact it's mind crushing most of the time as you are trying to cope with the other symptoms. However, if you keep at it and see that you do actually start to have some single vision after 1 year and 8 months of putting your vision first despite what everyone says is pretty cool. I wouldn't go so far to call it rewarding yet but still. Lately I can track birds and passing cars with both eyes and they don't go double, that's pretty neat too. You gotta live in your own mind though, no one is going to understand what's so awesome about it.

5. Frustration/Stress
Frustration and stress are part of the factors that made me end up in this mess. Once the whole thing comes down and all expectations are shattered, I tried to let go and manage the stress and frustration in a way that would not compromise the visual improvement. Now that's what I call FRUSTRATION... After twenty years of maltreatment and leaving you with this visual mess, you and no one else have to clean up. So after already losing all that time you realize you are gonna have to put your life on hold  and put in more years because of other peoples stupidity and try to acquire some basic skills most people have effortlessly.

6. Learning how to golf is not the same as overcoming visual brain deficits and VT is not a choice 
I like the guys attitude and stamina though. It's that kind of perseverance  that gets an adult through VT, except for the fact that this isn't just some kind of training. Visually traumatized patients really are sick and often are in a less favorable position financially because of it. So if you are unlucky enough to have your strabismus treated by regular eye doctors it's going to take an obsessive mind, lots of stamina, courage, pain and some kind of social network to help you. That's why I am very grateful I have been granted the opportunity to correct this grave error.

Tuesday, April 16, 2013

Session 51: The last 10%

I took the wrong train to get to my optometrists office today. I had to run and still arrived eight minutes late... At least I made it. The running however messed up my visual performance during this training session. I used to be a great runner but it's always been sort of a given that after running binocular vision isn't something to rely on. After I calmed down I did my regular exercises and talked to my optometrist about my experiences. About how over the last few weeks I have been able to track flying birds and driving cars without them going double. However normal those things might seem, this stuff is huge. I think smooth tracking, along with making swift saccades, is one of the most important prerequisites for stereo vision. Slowly but surely these skills keep improving. Hard to believe I ever got anything done without them. Well, it does explain the unreasonable amount of work and energy I wasted on getting anything done. That's not exactly the past either...

 Recently I was talking to a VT friend of mine named Robert about how I felt that a stereo vision break through might only be months away. He returned the feeling and in fact he expressed it far better than I did so I didn't want it to go to waste.
"I can visualize the successful conclusion of my therapy - it is tangible somehow. But at the same time, knowing how well my eyes have to be coordinated and how often (all the time...), at times it seems to me to be an impossible goal. So you say you are months away from a breakthrough. I can relate. I feel like I am close to a break through, yet paradoxically it is a long time off - as if the final 10% of progress will take a disproportionately long time."

I always tell myself it's a matter of time and effort and so it will be until the end.

Friday, April 12, 2013

What other visual anomalies do amblyopes have besides poor stereopsis or reduced visual acuity?

The major developmental binocular anomalies are amblyopia and strabismus. Amblyopes have other visual anomalies besides poor stereopsis or reduced visual acuity. They also have:

• poorer contrast sensitivity (sometimes just high spatial frequencies, central vision)
Most patients with amblyopia have reduced contrast sensitivity, in addition to poor visual acuity. The visual anomaly can differ, however if the amblyopia is caused by strabismus or optical defocus. Strabismic amblyopes tend to have poor contrast sensitivity in the central visual field only, but normal peripheral contrast sensitivity. Optical-deprivation amblyopes, on the other hand, tend to have poor contrast sensitivity across a larger portion of the visual field.

• reduced vernier acuity
Vernier acuity is the ability by a person to detect the proper alignment of two line segments. In most people, Vernier acuity is particularly high, enabling accurate differentiation between aligned and misaligned marks on a vernier scale.

• experience the crowding effect
People with amblyopia experience the crowding effect, which is described as difficulty reading a letter when it is surrounded by other letters or contours. For this reason, when testing visual acuity on amblyopes, you may measure a better visual acuity using isolated letters than if you use a single line or the entire chart. Also, when reading a row of letters, amblyopes can usually read the first and last letters more easily than the middle letters. The crowding effect is more pronounced in strabismic amblyopes than anisometropic amblyopes. Don't fail to read the recent Vision Help post on the crowding effect. Also check out Strabby's experiences with the crowding effect.

• reduced binocular luminance summation
In individuals with normal binocularity, pupils are about 30% smaller with binocular viewing than with monocular viewing. This is an indication of summation of the input from the two eyes. In amblyopia, this effect is less pronounced, indicating a less complete summation of luminance input from the two eyes. Persons with poorer stereopsis appear to have less effective summation. Photophobia is not uncommon as a consequence. The reduced summation is thought to be at the cortical level and not in the retina.

• slower neural transmission from the amblyopic eye

• abnormal space, direction and motion perception
Strabismic amblyopes also tend to have distorted space perception. This causes objects to appear distorted and causes an abnormal sense of visual direction. This may underlie the poorer-than-normal vernier acuity seen in some amblyopes.

Two other anomalies sometimes seen in strabismic and amblyopic patients are:
• Eccentric fixation
Amblyopic and strabismic eyes sometimes do not fixate normally. Fixation may be unstable, or the eye may have nystagmus. It may also be anomalous in the sense that some point other than the fovea is used for fixation. This is known as eccentric fixation.

Eccentric fixation can be present during both monocular and binocular viewing conditions, but it is best diagnosed under monocular viewing conditions. This is important to keep in mind to avoid confusion with anomalous correspondence, which we will consider later. Anomalous correspondence is relevant only during binocular fusion and must be measured in those conditions.

• Anomalous correspondence
Check out the Squinty Josh post on this topic.

Big thanks to Thomas O Salmon OD for his course on binocular vision
For more info:
- Deprivation and Binocular Vision Anomalies
- Developmental strabismus
- Amblyopia

Wednesday, April 10, 2013

The human visual system

"The sensory system that has been best looked at is the visual system. Primates are highly visual animals and it turns out that human beings probably have, in addition to the primary visual cortices, thirty or more other areas of the cortex devoted to vision. Let's think about what that's about... Here's this cortex that we thought of as higher order association cortex and now we find out that it's sensory in nature. Well, how do we get information about the world? We get it through our sensory systems and one of the things that characterizes human beings is the ability to make very fine distinctions based on input from sensory systems so that ever more elaborate behavior can occur from taking in that sensory information and having this wide variety of behaviors open to us. So the more information we get through our sensory systems and the more elaborate our cortex is for looking at that sensory information, then the more complex our behavior can be." , - 
Dr. Jeanette Norden, Professor of Cell and Developmental Biology in the School of Medicine, and Professor of Neurosciences in the College of Arts and Sciences at Vanderbilt University.

Another fascinating example of the fact that the visual system much more than the primary visual cortices is given in this excerpt from 'Through the Wormhole'.

"The human visual system consists at least of nine different pathways. Only one of those we are starting to understand, and the eight other ones are completely in the background." , - 
Beatrice de Gelder

However much we don't know about visual system yet, we do know how to improve it. We do know that the brain is plastic and we do know how to exploit this quality for the better in vision therapy.

Related articles:
- If Vision Therapy were an alternative treatment, what exactly would it be an alternative to?
- Analysis of strabismus and its effects, patient prognosis and success rate of vision therapy
- Book Review: Suddenly Successful: How Behavioral Optometry Helps You Overcome Learning, Health And Behavioral Problems