Visual Suppressions

Adverse visual suppressions are frequently an important complication of visual problems, while normal suppressions of visual and other input are advantageous. Suppressions facilitate the processing of information by filtering distracting stimuli. Suppression of extraneous stimuli is essential for sustained, selective attention. It is not possible to be consciously aware of all of the external and internal input that bombard our visual system.

Our eyes send more data to the brain than all of our other senses combined and there are as many nerve fibers from the brain to the eyes as there are from the eyes to the brain. These guide what the eyes look for and also influence the processing of input at the retinal level. Without suppressing non-essential stimuli, accurate visual perception would not be possible.

Adverse suppressions are caused by sensory mismatches. This is usually a binocular dysfunction in which the two eyes are not sending coordinated data to the brain. These occur when the two eyes do not focus equally or when they do not align precisely. Adverse suppressions reduce confusion to enable the individual to function, albeit with compromised efficiency and visual processing. Adverse suppressions can lead to prolonged maladaptations such as amblyopia and difficulty processing print.

Suppression of vision during rapid eye jumps is critical to visual function and comfort. Our eyes move four times a second even when we think that we think that we are locked onto a target. This is how the brain constructs our view of the world since our vision is only clear in the central 5o of our visual field. If vision is not suppressed during rapid eye movements the individual sees a smear. The brain fills in during rapid eye movements as it does when our eyes close during a blink.

These saccadic suppressions are critical for reading. When the timing of these suppressions is off, it makes it very difficult to get information from print. If it is a developmental visual problem, and the person has never seen any other way, they assume that this is what everyone experiences. When it happens as a result of a concussion, the individual is aware of the changes and is disabled and sickened by the effects.

Most people are aware of the fallacy of multi-tasking; that we cannot actually do two separate cognitive tasks at the same time. Alex Pang explains that this is over-generalized. If we are listening to someone and texting something else, we cannot process both simultaneously and must be switching back-and-forth rapidly. This impairs performance compared to doing each task separately. Alex Pang describes this as “switch-tasking” not multi-tasking. On the other-hand, being able to multi-task efficiently is essential to many things we do such as driving a car. Efficient reading is another example of what appears to be a unitary task it that requires a great deal of multi-tasking.

Vision must coordinate with other systems for us to function well. When they do not, when the systems are overloaded, adverse suppressions and sensory processing disorders occur. These include poor eye-hand coordination, dizziness, spatial disorientation, affective disorders, reading problems, attention disorders, and clumsiness.

For More:

Why Effective Amblyopia Treatment Requires Binocular Vision Rehibilitation

Tracking

Visual Perception and Who We Are

Vision, Body Schema, and Clumsiness

Optometric Vision Therapy

Our body image is how we see ourselves. Our body schema is our subconscious sense of our body and how it relates to the space immediately around us. Movement is necessary to develop vision and body schema and to integrate them which enables us to move effectively. Our conscious brain has difficulty accepting that most of what we do is subconscious. Even when our movements are consciously ordered, not reflexive, the implementation is largely subconscious. Our conscious mind and focal vision are the strategists which make the overall plan while the subconscious mind, body, and ambient vision direct the tactics. It is now thought that learning does not take place solely in the brain but also in the body.

Focal vision is conscious: seeing objects, colors and symbols; recognizing what we see despite differences in size, distance, and position. Ambient vision is as complex as focal vision but is subconscious. It monitors where we are and where things are around us. It assists our balance. It directs eye movements to obtain information with phenomenal speed and precision. It helps us simultaneously process the movement of multiple objects around us. It enables us to navigate while our conscious mind is occupied. It stabilizes the images of what we are moving past so we perceive that it is our body that is moving and not our surroundings. Ambient vision is faster than focal vision and is able to multitask to accomplish all that it does.  We are unaware of its existence until there is a problem.

Most of us develop adequate ambient visual skills and, if we don’t, we probably don’t realize it. We are who we are. We may become carsick easily, be clumsy, have difficulty tracking across a page to read, perceive movement that is not there, not coordinate our two eyes well, be uncomfortable in busy places, and be easily overstimulated compared with others, but we adapt and compensate. Unless the deficits are extreme, it also goes unnoticed by others. But these problems are obvious when they develop suddenly such as after a head injury and may be extreme.

It is intriguing to watch vision and body schema develop in infants. We have an infant grandson who just started sitting in a highchair. Being able to sit expands what he can do with his hands and vision. He can pick up food and start to get it into his mouth. Sometimes he can control letting go of things to accomplish the all-important milestone of dropping objects and watching them fall to the floor. This is the beginning of thousands of experiences of trying and developing.

If vision and body schema have not developed adequately, they have the potential to be improved through therapy. A surprising degree of plasticity remains even into old age. Just trying harder tends to reinforce inefficient behaviors, not foster change. The visual system can be incrementally modified through optometric vision therapy; an individualized sequence of activities. The new or modified skill must then be practiced with attentive repetition to become automatic. Effective attention is subconscious as is effective vision. Forced attention (concentration) is much less effective.

Attentive repetition is difficult to achieve in the infant and young child. When possible, carefully chosen games which rely on the developing visual skill are employed which stimulate engagement. Success in the game is dependent on improving the deficient visual skills. Games may also reduce the rehearsal required to become automatic because the skill is developing implicitly. The roles of the therapist and doctor are critical. They plan and modify the sequence of activities for each patient based on the diagnosis and progress. Knowledge and experience are critical, but the success of care is equally dependent on empathy and support as in all of the healing arts. Being scientific and evidence-based does not reduce the importance of the personal connections.

Most change has to be done consciously at first and then practiced until it becomes automatic. The actions are consciously directed, but all action is too intricate to be consciously controlled. The conditions need to be arranged to facilitate the subconscious creation of new patterns. Trying to guide a ball instead of looking at a target and throwing it naturally is a good example.

The role of personality in development and in therapy cannot be ignored. Some children are more adventurous. Some are less flexible and less resilient. Mindsets can change dramatically as a child becomes empowered through growth, but some are still resistant to change. This is influenced by a history of failures, but it can also be their inherent temperament.      

Some of the brightest and most determined patients can be the most challenging. Their intelligence and determination have enabled them to find ways to compensate. It can be difficult to get them to stop overthinking to enable their subconscious to guide the development of automaticity. A dog which loses a leg can soon learn to run effectively on three legs. Having minimal consciousness may be an asset in this circumstance.

The success of vision therapy is dependent on a team effort and dedication. Appointments need to be kept and reinforcement activities need to be practiced at home to foster automaticity. Temporary accommodations may be necessary in school to relieve the visual load.

Helping develop vision is natural. Our species would not survive without it and it does not usually require professional guidance. It is a primary reason for the importance of play. Further development of visual skills is critical for athletes, dancers, artists, TSA workers, those in law enforcement, and all children who are learning to read. However, this is not the same as rehabilitating visual dysfunctions. Doctors and therapists who have been certified by the College of Optometrists in Vision Development have demonstrated their knowledge and clinical skills in vision development and vision therapy.

For More:

The Brains Sense of Movement

Vision Therapy Changes in the Brain

Action in Perception

Why effective Amblyopia treatment requires binocular vision rehabilitation

Great post!

The VisionHelp Blog

Recognized as a significant vision problem that affects millions of people worldwide, one of the “hot topics” of  advocacy at the recent 2019 VisionHelp Annual Meeting  was Amblyopia. 

Amblyopia/Lazy eye is a serious neurodevelopmental vision problem that causes vision loss in approximately 2-4% of the population or 1 in 30 people. Neuroscience has shown that Amblyopia occurs when there is a unilateral failure in binocular vision, occurring early in life typically infancy or toddlerhood.

When the binocular system is broken at a young age, a neuroadaptation occurs, known as suppression where the signal from one eye is “shut down” by the brain to counteract the confusion created by the broken binocular system. As a result of this unilateral failure of binocular function a cascade of delayed visual function occurs leading to the following:

  1. Reduced visual acuity (eye sight) in one eye
  2. Reduced, or no stereo acuity (depth perception)
  3. Poor…

View original post 896 more words

Cribsheet

A Data-Driven Guide to Better, More Relaxed Parenting from Birth to Preschool

Emily Oster

This book fulfills its promise, but not as you might expect. Emily Oster is an economist. Her qualification for writing this book is her ability to evaluate research. Her reason is to enable others to avoid some of the confusion, worry, and guilt that she and her husband went through during this phase of parenting. The book’s primary message is to not feel guilty due to arguments opposed to your decisions. You need to do what works best for you and your family. Most parenting is not supported by credible research. This is due to constraints on how research is conducted and to human variability. Much research that is used to support positions only demonstrates correlation, not causation. Breast feeding is an example. While breast-fed children have been shown to have advantages, it is inconclusive because the mothers who decide to breast feed also tend to have advantages which cannot be factored out.  

The following information is supported by credible research which is not true about much of what you read on the internet. It is easy to read and is sprinkled with humorous anecdotes which demonstrates that parenting is not easy for anyone.

Postpartum depression occurs in 10 to 15 percent of births and is treatable. Approximately half of the time, the depression starts during the pregnancy which usually goes undetected. It usually becomes evident soon after giving birth, but it can appear months later. A personal history of depression or a family history of depression are predisposing factors.

90% of SIDS deaths occur in the first four months of life. The causes of SIDS are still poorly understood but significant risk factors have been identified. This is similar to many drugs that have been demonstrated to be effective even though we don’t fully understand the mechanism. There is good evidence that infants who sleep on their back are at a lower risk for SIDS. There is moderate evidence that bed sharing is risky. This risk is much higher if you or your partner smokes or drinks alcohol. Infants should have a wearable blanket in the crib. Sleeping on a sofa with an infant is very dangerous.

Vaccinations are among the most significant public health triumphs of the past hundred years… The scientific evidence of vaccinations is extremely clear: vaccinations are safe and effective…. There is one vaccination risk that is common and, while not serious, can be scary. The MMR vaccine is linked with febrile seizures – seizures that occur in infants or young children in association with a high fever. They typically do not have long-term consequences, but are very scary in the moment… About 2 to 3 percent of children in the US will have a febrile seizure before than are five years old (most of these are not vaccine associated)….In a study of 537,000 children – all the children born in Denmark from 1991 to 1998, they found no evidence that vaccinated children are more likely to be autistic; if anything, the results suggest vaccinated children are less likely to be diagnosed with autism.

In a group of children who were more likely to have peanut allergies, children who were exposed to peanuts were less likely to be allergic to them at the age of five than children who were not exposed. In the group that didn’t get peanuts, 17 percent of the children were allergic to peanuts at age five. (Remember, this figure is higher than it would be in the general population because of the way the researchers selected the sample.) However, only 3 percent of the children who were given peanuts were allergic… In the wake of these peanut findings, the recommendations about exposure have changed completely. Early exposure to peanuts is now the normal recommendation, especially for children at risk for allergy. (Let Them Eat Dirt)

There is a large range within which normal children meet developmental milestones. The following table is from the book. Many more could be added that are cognitive or behavioral. Note the extreme variations that are normal without long-range consequences.

Milestone                                                                                         Range

Sitting without support                                                                3.8 to 9.2 months

Standing with assistance                                                              4.8 to 11.4 months

Crawling (5% of kids never do)                                                   5.2 to 13.5 months

Walking with help                                                                          5.9 to 13.7 months

Standing alone                                                                                6.9 to 16.9 months

Walking alone                                                                                 8.2 to 17. 6 months

It is recognized that there isn’t any benefit, and perhaps some harm, from trying to accelerate development. Research shows that the average age of potty training has been delayed because it has been found that the children master it faster when they are older. How can wide developmental ranges be accepted as normal while educational expectations are narrow? It is expected that all children will be ready to read at the same time and to do so earlier than prior generations. There are many skills which need to have developed before children can start to learn to read without excessive effort and frustration; auditory-visual integration, the ability to sit still, prolonged attention, working memory, eye teaming, tracking, visualization, and delayed gratification. Being pushed to read before a child is ready does not have the same outcome as naturally learning to read when they are ready. If any of the prerequisite skills are outside normal variation, specific intervention is indicated.

For More:

How To Raise a Reader

What if Everbody Understood Childhood Development?

Let Them Eat Dirt

Factfulness

Hans Rosling

Hans Rosling was a professor of global health in Sweden. Astounded by the ignorance of his students on important issues, he toured around the world surveying his audiences with similar results. After studying the causes of the overly dramatic worldview held by most people, he made it his mission to educate people about how their instincts lead them to incorrect conclusions and to feeling overwhelmed. He demonstrates, in contradiction to our instincts, how the world is getting better in most ways. News is designed to capture these instincts and trap our attention, not to stimulate our more rational thinking. Developed in our evolutionary past, our primitive instincts do not consistently serve us as well in our larger and more complex world.  

The gap instinct: We tend to divide the world into them and us. This is one of the ways in which we simplify the world to make it easier to understand and easier to make decisions, but few important things are that simple.

The negativity instinct: We have a natural tendency to notice the bad more than the good. This instinct masks how things have been getting better and hinders our ability to see how they can continue to get better. It’s difficult to understand that things can be both bad and getting better at the same time.

The straight-line instinct: World population growth is an excellent example of the straight-line instinct. We all know that world population is increasing rapidly and this instinct causes us to predict a time when the earth is far too crowded. But the rate of growth has been slowing for decades and the UN predicts that the world’s population will level-off around 2100. The reason for this is that the birthrate has declined from 5 births per woman to less than 2.5 over the last 50 years. As women become more educated, have better health care and better income, and have access to contraceptives, they have less children.

The fear instinct: “If we are not careful, we come to believe that the unusual is usual.” The ability to stimulate fear is a significant factor in what gets presented as news. “The image of a dangerous world has never been broadcast more effectively than it is now while the world has never been safer.”

The size instinct: Large numbers shock us. The number of children who die each year is one of those horrible numbers; 4.2 million children in 2016. That was 3% of the number of children born that year. But 14.4 million children died in 1950, 15% of the total born in that year. These are bad numbers, but they are getting better.

The generalization instinct: Once again, generalizations help us to simplify and make decisions but averages tend to be very misleading (The End of Average). Knowing the majority misses many individual differences. Take Brexit for an example.

The destiny instinct: assumes that things never change. We tend to be change blind (The Invisible Gorilla). We were discussing a 1950s magazine this week which had an article about how a housewife should prepare for her husband coming home. That did not play out well in the next generation.

The single perspective instinct: A single perspective avoids cognitive dissonance, but few problems have a single cause or a single solution. Experts are particularly likely to fall into this trap because of the specificity of their training. “People who believe that democracy is the best way to run a country are often tempted to argue that democracy leads to or is even a requirement for other good things, like peace, social progress, health improvement and economic growth. But here’s the rub, and it is hard to accept: the evidence does not support their stance.”

The blame instinct: Placing blame is another simplification to find a clear, simple reason for why something happened which misses the more complex and incremental causes for most things – good and bad – and all of the associated people and events involved over time.

The fear instinct: Urgency is often used to cause us to make decisions without considering all of the options, not considering opposing positions, and not assessing possible unintended consequences. We usually have more time.

Hans Rosling was concerned that these traps are not being taught to children. They need to learn to be humble and to accept that being wrong is part of learning. This can reduce anxiety caused by the feeling that they always need to be right. They need to learn to critique information and to make comparisons, not just look at isolated numbers. They need to learn to find out about the author and the author’s perspectives, not to disqualify them, but to understand that it is important to know the person to enable you to interpret their thoughts. Data is much more available than in the past, but data without a humanistic perspective and history does not guarantee better decisions or a better quality of life.

For More:

The End of Average

The Invisible Gorilla

The Coddling of the American Mind: How Good Intentions and Bad Ideas are Setting up a Generation for Failure

To See and Not See

Oliver Sacks’ case study about Virgil appeared in An Anthropologist on Mars in 1994. Virgil was 50-years old and had been blind for 45 years due to dense cataracts prior to having surgery to allow him to see, but would he have vision? Like all of Dr. Sacks’ case studies, the story is interesting in itself, but is most valuable for what it tells us about the underlying neurological processes; the development and integration of vision with our other senses to enable us to make sense of the world. We have to be careful not to overgeneralize. Learning to see at 50 is not the same as learning to see at birth, but it does reveal complexities that we take for granted because they are subconscious and usually function well-enough to not interfere with our day-to-day activities. Everyone’s visual skills differ. In addition to not developing equally, visual skills can be disrupted due to injuries, neurological conditions, and aging. I will not presume to be able to improve on Dr. Sacks’ words. The italicized words are excerpted from his text.

The rest of us, born sighted, can scarcely imagine such confusion. For we, born with a full complement of senses, and correlating these, one with the other, create a sight world from the start, a world of visual objects and concepts and meanings. When we open our eyes each morning, it is upon a world we have spent a lifetime learning to see. We are not given the world: we make our world through incessant experience, categorization, memory, re-connection. But when Virgil opened his eye, after being blind for forty-five years – having had little more than an infant’s visual experience, and this long forgotten – there were no visual memories to support a perception; there was no world of experience and meaning awaiting him. He saw, but what he saw had no coherence. His retina and optic nerve were active, transmitting impulses, but his brain could make no sense of them. Everyone, Virgil included, expected something much simpler. A man opens his eyes, light enters and falls on the retina: he sees. It is as simple as that, we imagine.

But though his best vision was a respectable 20/80, he lacked a coherent visual field…it was almost impossible for the eye to fixate on targets; it kept losing them, making random searching movements, finding them, then losing them again.

One does not see, or sense, or perceive in isolation – perception is always linked to behavior and movement, to reaching out and exploring the world. It is insufficient to see; one must look as well.

Three days after surgery, they had gone to an IGA, and Virgil had seen shelves, fruit, cans, people, aisles, carts – so much that he got scared. “Everything ran together,” he said. He needed to get out of the store and close his eyes for a bit. People experience this who have post-concussion syndrome and who are on the autism spectrum. They are overwhelmed by stimuli most people assimilate.

While Virgil could recognize individual letters easily, he could not string them together – could not read or even see words. I found this puzzling, for he said that they used not only Braille but English in raised or inscribed letters at school – and that he had learned to read fairly fluently. Indeed, he could still easily read the inscriptions on war memorials and tombstones by touch. But his eyes seemed to fix on particular letters and to be incapable of the easy movement, the scanning, that is needed to read. This is what people experience with amblyopia and some forms of dyslexia. Since most people with amblyopia primarily have the problem in one eye, their reading is different with each eye.

As Virgil explored the rooms of his house, investigating, so to speak, the visual construction of the world, I was reminded of an infant moving his hand to and fro before his eyes, waggling his head, turning it this way and that, in his primal construction of the world. Most of us have no sense of the immensity of this construction, for we perform it seamlessly, unconsciously, thousands of times every day, at a glance.

Virgil had now had two hours of testing and was beginning to get tired – both visually and cognitively tired, as he had tended to do since the operation – and when he got tired he could see less and less, and he had more and more difficulty making sense of what he could see. Most of us have visual, mental, and physical reserves so we don’t experience this or the effects are minimal. Once again, this is not true for people who have less resilience; those whose vision requires conscious attention and compensation, or have early dementia, head injuries, or autism.

For More:

Scanning

Growing up with Sensory Issues: Insider Tips from a Woman with Autism

Resilience

Crowding

Rest

Alex Soojung-Kim Pang

Work, school, organized sports, parenting, care of other family members, and taking care of necessities consumes most of our time and usually comes with some degree of stress. Recommendations for healthy lifestyles include a healthy diet, drinking lots of water, and exercise. Other means of building or restoring our resilience are often overlooked. These include play, hobbies, volunteering, rest, and sleep.

But if rest and sleep were drugs, they would be considered miracle drugs and they don’t have dangerous side-effects. If we think that the cost of sleep is too much because we have too much to do, we’re probably wrong. The evidence is overwhelming that we get more done when we get adequate rest. We think better and are healthier. A lack of sleep causes weight gain.

Alex Tang provides copious scientific evidence and examples to support this message. Arianna Huffington, who wrote Transforming Your Life One Night at a Time, wrote the Forward which provides an overview of the book. My primary reservation about the book, other than too many examples, is that it does not address children who are often more sleep-deprived than their parents. Previous blogs have addressed anxiety, depression, and self-destructive thoughts, all of which are on the rise for children and young adults. There are many causes for these problems but lack of sleep, which erodes executive function, is one of those reasons.  

Take rest seriously: Too often we treat rest as merely the absence of work, or something that gets in the way of reaching our goals. In reality, hard work and deliberate rest are partners; each sustains and supports the other.

Focus: One way to create space for rest is to structure our daily schedules around unbroken periods of focused work. You can be a lot more productive in a couple of hours than in a day full of distractions and notifications. And chances are, your day is full of distractions: the average knowledge worker loses two to four hours each day to distractions, unnecessary meetings, and technology-driven interruptions. And as the science shows, multitasking is a myth and doesn’t work. (If your day involves extensive use of electronic displays, short breaks to get up and move and let your eyes refocus will also enhance your performance.)

Layer work and rest: By resting immediately after a period of focused work, you can give your subconscious time to discover solutions to problems that are eluding your conscious effort. Walking creates an ideal break for many people.

Get an early start: Many people do their most important work in the early morning.

Detach from work: Taking the time to rest is important, but so is paying attention to the quality of your rest. The more detachment you have, the more restorative your downtime will be. Detachment is partly a matter of not doing things, but it is also about doing things that occupy your mind enough to keep work from intruding.

Detach from devices: Achieving the kind of detachment we need for productive rest can’t really be done without regularly disconnecting from our devices. As Sherry Turkle noted in her book Reclaiming Conversation, the mere presence of a smartphone or device, even when it is not being used, alters our inner world and our connections with others.

Take a week off every season: Scientists have found that the happiness and relaxation we feel on vacation peaks after about a week, while the psychological benefits of a vacation last up to two months, but if you can’t take a week off every three months, take the vacation that fits into your schedule.

Practice deep play: People who have long, productive lives practice “deep play”. They have hobbies or enjoy sports or activities that offer some of the same psychological rewards as their jobs but in a different setting, and without the frustrations of work.

Get plenty of exercise: The more movement you have in your life, the better your brain can perform. Exercise also makes us more resilient, better able to handle stress, and helps us live longer, healthier lives.

Get plenty of sleep: Perhaps the most destructive myth of our work-obsessed culture is that sleep deprivation is a sign of commitment to one’s job. Sleep doesn’t just provide physical rest; it’s actually a time of incredible mental activity, giving our brains time to consolidate memories and skills, and clear out toxins that are associated with dementia late in life.

For More:

The Distraction Addiction

Resilience

How Sleep Can Heal our Brains

Nurture Shock: New Thinking About Children

The Importance of Sleep