What role do various brain areas play in vision? - Part 2

I admit this is DIY brain science, although putting together the information I found on the various brain areas described in Part 1 was very eye-opening to me. That's why I made a schematic overview of the information listed earlier and categorized them into functional groups. This schedule has many deficits in being simplistic, incomplete (because actually at least 50% of the brain is involved in visual processing) and not adequate in conveying the true complexity of the holistic brain. Nonetheless it makes up for those flaws by illustrating  in an easy intuitive way why binocular vision problems affect so many, if not all, brain functions and every aspect of life. Eyes that are not teaming correctly are like an open loop in the brain making for a lot of lost energy and personal potential on the one hand, and heightened susceptibility to a variety of psychological and neurological disorders on the other hand. How a person with a visual disability experiences his problem varies because each person with a brain abnormality or injury has uniquely affected areas so the real life examples given below might not apply to every single case. However it is generally true that customized vision therapy can considerably increase personal potential and quality of life of a visually impaired patient by structurally reversing this downward spiral in the brain.

Click to enlarge!

In the picture the six brain areas described in detail in Part 1 are divided into overlapping functional groups: autonomic, sensory, motor and cognitive. In an another previous post I mentioned that vision imbalances are not a cause but rather a symptom of deficits in the function and performance between two major nerve systems in the body: the autonomic and motor nerve systems.  Now, by taking in the additional information that eye movement is administered by the basal ganglia and thalamus in close collaboration with brain stem,  cerrebelum and cortex we get a first gimps of how massive the influence of incorrect visual development is. An initial imbalance in the basal ganglia itself can affect balance, posture, cognitive, emotional and addictive behavior. Furthermore does eye misalignment disrupt the received sensory input and its processing affecting sensory experience, concentration, memory and motor skills further down the line. Over time a negative brain wide spill over effect will eat away at overall performance. In her book 'Fixing my gaze' Susan Barry states that according to her own personal experience stereo vision isn't just another way of seeing but that it is truly another way of thinking! Vision cannot be isolated from cognition or any other brain function so correcting a visual imbalance through appropriate training has far reaching positive effects on the brain as a whole.

Plenty of life experiences can illustrate my analysis.

- Getting 'stupider': When going to university I still suppressed one of my eyes as an adaptation to my long standing strabismus. I was so convinced I needed to succeed that after one semester of relentless studying I actually broke through my suppression. Panicking, I went to my ophthalmologist asking him for help and he said the only thing he could do is operate. In my ignorance I let him, embarking on a long journey of suffering lasting up until this day. In the meantime I kept studying, being of the opinion that I shouldn't let my life be ruined because of other peoples mistakes. I kept passing exams... However there was a big price to pay. On paper it might have looked like I was getting through my studies and 'getting smarter', but in reality I was getting stupider. Gradually I was losing my ability to focus, to read properly and ultimately to function normally. So in the end they still managed to ruin my life, but it's never too late as they say... (Thalamus)

- Having to relearn everything: After that badly executed surgery at age 18 resulting in horrendous double vision, I had a very hard time relearning everything. Learning how to walk, how to navigate, how to drive, how to everything... I did relearn all those things quite fast but not to the former level... yet. :) The surgery had actually restricted eye movements so I could not freely adjust them to go back to my old strabismic habits, even though there was no new system either. I lost a lot of control over my eyes in that surgery and mostly my recovery is about overcoming that surgery more than the initial strabismus. (brainstem, cerebellum, hippocampus, thalamus,...)

- Burn outs: After a few years of trying to live with the double vision and the additional problems created by the surgeon while at the same time trying to live a normal life as a student, I eventually had trouble coping and burned out two years in a row leaving me utterly exhausted for months. Fortunately this led me to think out of the box and look for another long overdue solution in English on the internet: Vision Therapy. (brain stem, cerebellum, hippocampus, thalamus, cortex,...)

- 'Shock therapy': By miraculously graduating I had promoted myself from student to 'most wanted villain' it seemed. My parents had forgotten about my troubles they weren't able to relate to begin with. Not knowing anything about the problem or having ever done anything to help me after I got messed up even more by the surgeries, everyone felt very in place to give me advice and even get angry at me for not being able to do anything anymore. After losing a visual comfort zone years ago, I also lost a geographical one. This emotional shock of realizing that I had no home and recovery, if even possible, was at least two years away made me lose months of recovery. The results of that unnecessary brain shock, I still feel today. It's easy to destroy and hard to rebuild. Ignorance and intolerance kill. (basal ganglia, brainstem, thalamus, ...)

- Motor problems: I used to be a great runner. After all that happened and the recovery sucking up all my energy, I just can't do it anymore. I take small walks now. I don't go far and when I do go somewhere knowing there won't be much of a plan B to get out of the situation I'm scared of 'imploding'. I'm 23, but often I feel like 83.  (motor group)

- Not being able to react to situations: When all this went down I tried to explain to a sympathetic friend how all this fear and stress in combination with the long standing vision problem was affecting me. I said something like: 'I know I'm here right now and I'm here with you. I'm comfortable because I know this house and I know you. But if something slightly unexpected were to happen I would perceive it but wouldn't be able to react. I realize what is happening but I'm not able to react to what is happening. I can perceive the situation but I don't feel like I'm really part of it. It's like there is a short circuit in my head.' He said: 'Jesus, sounds like something I read about dementia.' An interesting article that provide more insight of what might be going on up there appeared on the Vision Help blog:  http://visionhelp.wordpress.com/2011/05/22/sensorimotor-dynamics-and-two-visual-systems-shades-of-skeffington-brock-part-1/ . (thalamus, brain stem, cerebellum, basal ganglia, ... )

- 'Locked in': This brain issue has taken over my life and everything I do is in order to recover. I can't go where I want, can't read all I want, basically I can't live my life... But I'm working my way out now and if everything remains to be on an even keel I will succeed. Achieving stereo vision will eventually reverse the downward spiral and enable me to get better. (sensory, motor groups)

- The harder you fight it, the worse it gets: Binocular imbalances clearly put a lot of strain on the brain and body and the harder you fight it by not accepting reality and not correctly treating with Vision Therapy the more damage will be done. It's wise to accept the situation (if you are not misinformed by MDs and if people let you) and work on your vision in order to close this energy wasting 'brain leak'. After you can get back to other things you want to do in life. Ignoring this problem doesn't last. A person divided against himself, can not stand.

If this is true for a normal brain, I wonder how much of my energy I'm spending over there...

- Sensibility to sound: Some strabismics compensate very strongly for visual impairments towards audio processing. I'm a good listener and I can quite easily pick up languages auditively with some extra visual learning. Sadly some people have reorganized their senses in such an extreme way they are oversensitive to sound and suffer because of it. An example can be found here. (thalamus, sensory group)

These are just a few illustrative experiences of how strabismus or other visual trauma can affect the brain and why treating with Vision Therapy as soon as possible is imperative in order to limit and repair the damage. Vision, even though often taken for granted, is a learned behavior and can be improved through training according to the principle of neuroplasticity!

Finally, I want to end with a remarkable excerpt from  'The Brain that changes itself' by Norman Doidge pointing out once more the profound implications that vision problems and whether correctly treated can have on a persons brain and consequently his overall development, performance and health status.

Michael Merzenich continues to challenge the view that we are stuck with the brain we have at birth. The brain is structured by its constant collaboration with the world, and it is not only the parts of the brain most exposed to the world, such as our senses, that are shaped by experience. Plastic change, caused by our experience, travels deep into the brain and ultimately even into our genes, molding them as well.

What role do various brain areas play in vision? - Part 1

After previously writing about the basal ganglia and the crucial role they play in vision and brain plasticity, I was intrigued and wanted to understand what implications binocular vision dysfunctions have for the brain as a whole more thoroughly. In this post, part 1, I will introduce more related brain areas involved in visual processing one by one. In part 2 I want to provide a more cohesive view of what is told in part 1, a illustrative summary if you will, explaining how this relates to earlier discoveries and my own experiences over the years.

CORTEX
The cerebral cortex is connected to various subcortical structures such as the thalamus and the basal ganglia, sending information to them along efferent connections and receiving information from them via afferent connections. Most sensory information is routed to the cerebral cortex via the thalamus. The cortex is commonly described as comprising three parts: sensory, motor, and association areas.


BASAL GANGLIA - The basal ganglia and what they do for you
The basal ganglia comprise a group of structures that regulate initiation of movements, balance, eye movements and posture. They are strongly connected to other motor areas in the brain and link the thalamus with the motor cortex. The basal ganglia are also involved in cognitive and emotional behavior and play an important role in reward and reinforcement, addictive behaviors and habit formation.

THALAMUS
The thalamus is heavily involved in relaying and processing sensory information between cortex and brain stem and  within cortical structures. Because of its role as relay between various subcortical areas and the cerebral cortex, the thalamus contributes to many processes in the brain including perception, attention, timing and movement. It plays a central role in alertness and awareness.

Sensory function
For the visual system, for example inputs from the retina are sent to the lateral geniculate nucleus of the thalamus, which in turn projects to the primary visual cortex (area V1) in the occipital lobe. Similarly the medial geniculate nucleus acts as a key auditory relay between the inferior colliculus of the midbrain and the primary auditory cortex etc.

The thalamus is believed to both process sensory information as well as relay it - each of the primary sensory relay areas receives strong "back projections" from the cerebral cortex.

The thalamus also plays an important role in regulating states of sleep and wakefulness. Thalamic nuclei have strong reciprocal connections with the cerebral cortex forming thalamo-cortico-thalamic circuits that are believed to be involved with consciousness.

Motor function
 A major role of the thalamus is devoted to "motor" systems. The neural information processes necessary for motor control were proposed as a network involving the thalamus as a subcortical motor center  Through investigations of the anatomy of the brains of primates the nature of the interconnected tissues of the cerebellum (see below) to the multiple motor cortices suggested that the thalamus fulfills a key function in providing the specific channels from the basal ganglia and cerebellum to the cortical motor areas. In an investigation of the saccade and antisaccade motor response in three monkeys, the thalamic regions were found to be involved in the generation of antisaccade eye-movement.

The role of the thalamus in the more anterior pallidal and nigral territories in the basal ganglia system disturbances is recognized but still poorly understood.

Memory function
The thalamus is functionally connected to the hippocampus (see below) as part of the extended hippocampal system at the thalamic anterior nuclei with respect to spatial memory and spatial sensory datum they are crucial for human episodic memory and rodent event memory. There is support for the hypothesis that thalamic regions connection to particular parts of the mesio-temporal lobe provide differentiation of the functioning of recollective and familiarity memory.

CEREBELLUM
The cerebellum monitors and regulates motor behavior, particularly automatic movements. Some recent studies have associated the cerebellum with cognitive functions, such as learning and attention. Although the cerebellum accounts for roughly 10% of total brain weight, it contains more neurons than the rest of the brain combined.

HIPPOCAMPUS
The hippocampus is the structure in the brain most closely aligned to memory formation. It is important as an early storage place for long-term memory, and it is involved in the transition of long-term memory to even more enduring permanent memory. The hippocampus also plays an important role in spacial navigation. For a TED talk on the hippocampus click here.

The above text is mainly based on Wikipedia and the 3DBrain Android application. It's possible you don't really see the connection between these facts and more importantly why they are such a big deal to understanding the true nature and effect of vision dysfunctions, so stay tuned for Part 2 in which everything will come together through (graphic) illustration.

What role do various brain regions play in vision? - Part 2

The importance of sleep

An excerpt of 'The brain that changes itself' struck me as particularly explanatory of why proper sleep is so important to recover from visual brain damage. It also explains why not getting the amount of sleep needed or interruptions of my sleep don't just feel like a bad day but as a step closer to the abyss. So sleep certainly isn't death's cousin, not sleeping properly is...

Scores of studies show that sleep helps us consolidate learning and memory and effects plastic change. When we learn a skill during the day, we will be better at it the next day if we have a good night's sleep. "Sleeping on a problem" often does make sense.

A team led by Marcos Frank has also shown that sleep enhances neuroplasticity during the critical period when most plastic change takes place. Recall that Hubel and Wiesel blocked one eye of a kitten in the critical period and showed that the brain map for the blocked eye was taken over by the good eye — a case of use it or lose it. Frank's team did the same experiment with two groups of kittens, one group that it deprived of sleep, and another group that got a full amount of it. They found that the more sleep the kittens got, the greater the plastic change in their brain map.

The dream state also facilitates plastic change. Sleep is divided into two stages, and most of our dreaming occurs during one of them, called rapid-eye-movement sleep, or REM sleep. Infants spend many more hours in REM sleep than adults, and it is during infancy that neuroplastic change occurs most rapidly. In fact, REM sleep is required for the plastic development of the brain in infancy.

A team led by Gerald Marks did a study similar to Frank's that looked at the effects of REM sleep on kittens and on their brain structure. Marks found that in kittens deprived of REM sleep, the neurons in their visual cortex were actually smaller, so REM sleep seems necessary for neurons to grow normally. REM sleep has also been shown to be particularly important for enhancing our ability to retain emotional memories and for allowing the hippocampus to turn short-term memories of the day before into long-term ones (i.e., it helps make memories more permanent, leading to structural change in the brain).

Youtube Book Review: The brain that changes itself

In 'Fixing my Gaze' Susan Barry describes the marvels that brain plasticity has brought to her life through engaging in optometric vision therapy and overcoming strabismus. It also made clear that vision is not something that can be isolated from the rest of the body or brain, since vision is the major source of sensory input and affects the way we think and everything we do. Neuroplasticity is the new Buzz word and I was wondering how far this principle goes and what implications it has, not only for vision care, but also for other kinds of brain disorders. 'The Brain That Changes Itself: Stories of Personal Triumph from the Frontiers of Brain Science' by Norman Doidge provides many of the answers or partial answers to that question. Even though not dealing with vision as such, sensory plasticity is also covered in the book.



I found out about the book through a Youtube review which can be watched below. The review is thorough but is in no way a substitute for reading or listening to the complete book.

Another video I want to share related to this book is an interview with the author Norman Doidge. Something particularly troublesome to me is when asked whether these discoveries are finding their way to conventional medicine the answer is 'Not quite'... This is really too bad because applications of the paradigm shift discussed in this book open up the possibility of treating people of all ages who are suffering from countless neurological and psychological disorders in new more effective ways and by doing so augment the quality of life of those patients considerably.

This book also reveals once more how much ahead of its time developmental or behavioral optometry really was when developing the practice of visual rehabilitation or vision therapy at the beginning of the 20th century and refining it over the years. I totally recommend this book to anyone interested in the brain and especially to Vision Therapy patients who are doubting or are in need of renewed motivation. Also available on audio book!

Session 49: From the outside in

The procedures I am doing or tools I'm using to advance are not particularly mind blowing, but results don't fail to produce themselves. It's been five months since I started to see single some of the time and that trend continues. The first twenty months of vision training I was advancing because my measured angle of disparity was diminishing but nonetheless I kept experiencing double vision 24/7. A serious neurological symptom of an acquired developmental brain injury called strabismus that was left untreated for 17 years. Nowadays maintaining single vision is still more a voluntary movement than an automatic one so I soldier on. Even though having to really work for my vision every second I have my eyes opened, it's nice to see the progress and to be able to see that very basic rough movements are getting smoother. I can SEE I am moving forward towards finer vision motor skills. Like going from a very rough impressionist painting to a detailed realistic picture. Or sculpting a rock into a life like statue. Or from speaking a language like a cave man, towards fluency. My grandma commented 'A children don't learn how to speak in just one year, do they?'. Nope, they don't even though their little brains are more susceptible to learning. It's still going to take a while before all these new skills will flow into fully functional stereo vision that gives me more freedom to read or to do other vital activities but every day I am getting closer.

On an unrelated note, I'm glad Obama is going to boost neuroresearch. Hopefully the discoveries that will be done won't take another century to reach all health care practitioners. The concept of brain plasticity already has massive implications for treatment of all kinds of disorders and illnesses. Many opportunities could be seized right now with the knowledge we already have, if only the majority of doctors opened their minds to it. Even though not dealing with vision directly, the book 'The brain that changes itself: Stories of Personal Triumph from the Frontiers of Brain Science' by Norman Doidge shows once more how much the field of behavioral optometry was ahead of its time. A century of proper vision care lost... Let's hope that changes soon.

If Vision Therapy were an alternative treatment, what exactly is it an alternative to?

Nothing annoys me more than someone calling developmental or behavioral optometry ‘alternative medicine’. What exactly is it an alternative to? Cutting into peoples eye muscles leaving them with an even greater challenge to overcome? Too often poor eye control is blamed on the muscles surrounding the eyes and surgery is advised to alter the length of the muscles. The cause of strabismus however is at the cortical level (in the brain) and cutting the eye muscles is rarely of benefit other than in rare cases of paralysis or partial paralysis of muscles. In too many cases surgery leaves the patient even further from a cure because of the extra physical trauma that has to be overcome adding to the initial brain problem. Sometimes surgery can help someone to come closer to eye alignment but Optometric Vision Therapy, also called visual rehabilitation, is the ONLY way to really cure strabismus at the cortical level and acquire healthy stereo vision through practice.  Whether you had surgery or not, visual rehabilitation is necessary to effectively treat binocular vision problems. As I posted earlier: strabismus is less of a problem to be cured, than to be controlled.

Spreading information that indicates otherwise is unethical and nothing short of assault. If someone claims something of this sort out of ignorance, it’s negligence. If they know better and still don’t act accordingly, it’s criminal negligence and they don’t deserve to call themselves doctors.

Having excellent vision themselves most ophthalmologists focus on the aesthetic side of strabismus and don’t realize what kind of mental strain vision imbalances put on a person’s brain. The academic, physical, emotional, social and financial opportunity costs of not being treated with VT as soon as needed are huge for the individual and for society. On top of the 4% strabismics, there’s a huge group of roughly 20% of the general population with more subtle binocular eye problems not being handed the tools to a better life. They cannot reach up to their potential, get (mental) health problems, cannot maintain normal social relationships and more than once are financially punished for their undetected and untreated vision problem because of inability to perform adequately. Any eye doctor not trying to combat this great injustice with the neuroscientific truth that Vision Therapy allows children and motivated adults to alter their vision should find another profession.

Peer reviewed study:

- Recovery of stereopsis through perceptual learning in human adults with abnormal binocular vision

Related articles of the Vision Help Blog:

- The Deliberate Deception

- Le massacre des muscles oculaires

- Who's looking out for these kids? Uncovering the red herring in vision screenings

- Quid pro quo - VT works