Blindness in scientific Reesearch

People who deviate physically or psychologically from the average are a popular subject of scientific research. Oliver Sacks and V. S. Ramachandran have published numerous case histories on this basis. The reason for this is that the deviation allows you to study how it actually works. In “The Blind Woman Who Can See,” Ramachandran introduces a woman who is actually blind, but can purposefully reach for a pen that is held out to her. This lady's visual center is functioning and she is able to respond to instinctive stimuli. But she cannot consciously process visual information.

Of course, it's not about exploiting these sometimes difficult fates for research. If we find out why such deviations occur, it will hopefully be possible to develop aids, medications or therapies for those affected. This only works if these phenomena are systematically examined. It is also not uncommon for readers to find themselves in these case stories and find an explanation for their own problems for the first time.

Blindness has long been studied scientifically. In many cases it is about finding out the causes of eye diseases and preventing blindness. The aim is also to investigate how the brain and behavior change when a person cannot see. Orientation for blind people is of interest to the military, for example. Soldiers on deployment occasionally have to move through unfamiliar terrain. The visibility can be very small. A model for Braille was the night writing system developed by a military force.

Sight is the most important sense for humans. A large part of the brain's capacity is designed to process visual impressions. As shown in the previous chapters, vision is important not only for orientation or for everyday tasks. It also plays a huge role in social interaction and communication. The differences between those who are blind at birth and those who are sighted are an excellent way to study which part of body language is learned or innate.

Therapies and healing methods for eye diseases are primarily investigated in medicine. This is important, but not particularly exciting. Therapy either works or it doesn't work, so I won't cover it further in this book. Neural and social aspects are primarily researched by cognitive psychologists, and we would like to take a closer look at their results here.

Brain and senses

The brain is extremely adaptable. Many blind people perform extremely well when it comes to interpreting auditory, olfactory and tactile signals.

Children who are blind at birth find it much easier to adjust to the blind world. The older a person is when they become blind, the more difficult it will be for them to adapt to blindness. This is due to the fact that children can generally adapt more quickly; for them, life itself is a constant learning process. Children who are blind at birth do not have to adapt at all, but older children can also adapt quickly.

In addition to cognitive flexibility, i.e. the adaptation of brain and sensory performance, there are other challenges for older people. Correct use of a blind cane requires a certain amount of fine motor skills; for Braille you need a minimum of sensitivity in your fingers. Older people find it much more difficult to learn these techniques because they often no longer have the physiological abilities.

But there is also an individual factor: the more active a person is, the more adaptable they are. Unfortunately, many older blind people tend to stay at home or only go on excursions when accompanied. Muscles that are not trained break down. The same applies to sensory stimuli that are not sufficiently stimulated.

There is no special place in the brain where sensory information is processed. Instead, the brain breaks down the incoming signals in order to process them further in different areas. Let's say a red ball rolls towards us: then the information red, round and roll is processed by different parts of the brain. This isn't surprising, especially when you see it. We use our eyesight to orientate ourselves, play football or read. These numerous tasks can only be accomplished when different parts of the brain come into play. Therefore, it is not surprising that the brains of blind people do not function significantly differently than those of sighted people. There are differences, of course: sighted people focus on processing visual information, while blind people use these resources to process information from other senses, especially haptics and acoustics.

Apparently the visual center is not only used to process visual stimuli. It is also used in the creation of visual images and in dreams, i.e. in cases in which one is not actually actively seeing anything. This idea is at least obvious when you look at the different experiences of blind people. John Hull reports that some time after his blindness he lost all visual imagination. He even forgot that objects had to have something like a visual appearance. Others, however, report good imagination. The blind psychologist Zoltán Törey was able to create a visual representation in his mind's eye that, for example, enabled him to re-roof his roof. Many blind women have a very specific idea of what hairstyle, clothing or makeup suits them. Is it because they receive good advice, or is there more?

Another exciting question is whether blind people can memorize the structure of complex objects as well as sighted people. We know that sighted people have excellent memory for faces. This goes so far that you recognize people who you have only seen briefly and who you may meet again years later, although their stature, hairstyle or clothing may have changed.

Blind people are likely to have a kind of tactile memory that allows them to remember complex shapes better than sighted people. The blind biologist Geerat Vermeij was able to identify new species of molluscs based on tiny differences. Blind people rely heavily on tactile landmarks to help them find their way around. This also includes small differences in the asphalt, changes in ground conditions or edges with different heights. Blind people are also excellent at remembering the position of objects, for example on the breakfast table. This means they can reach for the coffee cup unerringly or put it back on the saucer.

This doesn't seem particularly remarkable at first, but many of these differences are only perceived indirectly, for example through the shoes or the cane.

A less encouraging finding by neuropsychologists is that multisensory perception works better than perception via a single sense. This means, for example, that we understand a person better when we hear their words and see their lip movements. In fact, trained lip readers can read up to 30 percent of the lips. Of course, for sighted people without this ability it is significantly less, but lip reading still passively contributes to understanding. So the remark “Please speak louder, it’s dark” isn’t all that absurd. Lip reading helps you understand people even in noisy environments such as discos. Apart from the fact that you probably won't have any in-depth discussions in such places.

But this also shows how complex the processing of sensory information is. As I already explained in the section on the orientation of blind people, the brain not only brings together sensory stimuli, but enriches them with memories and emotions. The exciting thing about these findings is that the brain doesn't work like a computer. We can imagine the brain as a network of different units. Units that are used more often connect stronger, while connections that are used less often become weaker.

All late-blind people find it more or less difficult to adapt to the new situation. The message for them – and everyone else facing similar problems – practice, practice, practice. The worst thing they can do is try to avoid the challenge.

Congenital and late blind people

Research is also focusing on the difference between those who are blind at birth and those who become blind late. Most researchers specifically look for people who were blind at birth because the differences to sighted people are most pronounced or are easiest to determine. The brain of those born blind has never learned to process visual stimuli. This makes it easier to use imaging techniques to examine which parts of the brain are actually important for vision. One would actually assume that after, say, a few years, there would no longer be any difference in the cognitive processing of information between those who were born blind and those who were blind later. That's not the case.

Many questions have not yet been clearly answered. For example, how well is the brain of late blind people able to use the visual cortex for other tasks? Can people who become blind from late onset develop similarly good spatial ideas as people who are blind at birth? If we consider that blindness occurs primarily in old age, such questions become increasingly important.

The brain of a person who is blind at birth processes tactile information differently than that of a person who is blind at birth. People who are blind at birth can use the visual cortex, which processes visual information, for tactile perception. Although the area responsible for processing tactile stimuli is enlarged in late-blind people, they process these stimuli differently than people who were blind at birth. Scientists can now partially switch off the visual cortex. In such an experiment, those who were blind at birth were no longer able to read Braille, while those who were blind later had fewer problems.

The exciting question is whether late-blind people can, with enough practice, become as fit at orienting themselves or reading Braille as people who were blind at birth. The next question would be what factors are crucial for people with late blindness to achieve such achievements: Does it just depend on training and experience or are there other factors that can be helpful in acquiring and improving these skills?

See with your ears

There are people who experience smells or music as colors or vice versa. This perception is called synesthesia. Blind people can also be synesthetes. Researchers have long been thinking about how sensory experiences can be replaced by another sense; this is called sensory substitution.

The Hebrew University of Jerusalem, for example, is researching how visual impressions can be translated into sounds. The goal is to convey quasi-visual impressions using different sounds and sound constellations.

An example: Blind people only perceive the part of the space that they can reach with their body or the blind cane. They may be able to tell how big a room is or where the next obstacle is via noise, drafts or echoes. But they do not have a three-dimensional image of the environment that a sighted person can easily create. This should change with sensory replacement devices. Since they use one sense, in this case hearing, to replace another sense – vision, such devices are called sensory substitute devices. Instead of explaining to a blind person what a landscape looks like or what colors are, they are offered acoustic analogies in the form of sounds or soundscapes.

Research from Hebbrew University shows that with a little training, blind people quickly learn to develop a mental image of the environment or objects. For example, the researchers generated a sequence of sounds that the blind test subject was able to identify as a face. It actually seems to be the case that the part of the brain that is actually responsible for processing visual impressions is used for this task.

One may ask whether a verbal description would not make more sense in this case. That's not her. Imagine watching a movie with an audio description for the blind. Turn off the image and just listen to the audio description. You will quickly notice that although essential aspects of the film are described, the audio description does not convey many visual impressions at all. Even if the audio description could be expanded at any time, it could still not offer an adequate replacement for the visual representation. It would be the same with textual descriptions. This is simply because one sensory experience is best replaced by another sensory experience.

Can blind people do better...?

Unfortunately, I have to dispel some myths about the abilities of blind people. Nobody should be embarrassed if they believe such things; they are often spread by blind people themselves.

Based on current knowledge, although training certain skills improves those skills, it does not necessarily improve other related skills. Blind people may be able to orientate themselves excellently with acoustic signals, but that does not automatically make them better sound engineers or musicians.

Blind people are generally better at what they need and have trained to do on a regular basis. Sighted people can become just as good at these skills if they practice just as hard.

Adaptation to missing senses begins immediately when they are lost. Visitors to dark cafés report a sharper sense of smell and hearing after just a few minutes. We don't currently know whether this is because the other senses are simply used or perceived more intensively due to the lack of visual stimuli, or whether the senses actually become more sensitive. But we can assume the former. Even if the human body can adapt quickly, it doesn't happen that quickly. In addition, as far as we know, the sharpening is only temporary - that is, a few minutes after visiting the café you can concentrate fully on your vision again.

There is much to suggest that blind people are particularly good at the skills that they train regularly. A blind person can easily pinpoint the origin of sounds, but that doesn't necessarily make them a good musician. He may be good at judging the quality of a food by smell, but that doesn't make him a born perfumer. Of course, this also applies the other way around: a musician is not necessarily good at recognizing everyday noises, and a perfumer is not automatically a good cook. This is often the catch when it comes to intelligence training. Someone may be an excellent chess player and a terrible political strategist. He may be good at memory but still can't remember faces. Unfortunately, the world is not as simple as we would like.

So Stevie Wonder, Vanessa Mae or Ray Charles are not such successful musicians because they are blind, but because they worked hard. It may be that some of the talents are innate. Blindness can encourage certain hobbies, but in the end it is hard work and practice that make the difference between mediocrity and mastery, not blindness.

A few years ago, the psychologist Brigitte Röder showed that blind people are better able than sighted people to recognize people by their voice. However, it also showed that sighted people can recognize other people better by their faces than blind people can by their voice.

I particularly emphasize this aspect because assumptions about the great abilities of blind people can not only benefit, but also harm. For example, anyone who believes that blind people can hear particularly well will often assume that they are not suitable for “visual” tasks such as working on a computer. Allianz board member Clement Booth wrote in a guest article for Welt Online that blind people are particularly good telephone operators because they can listen well.

Unfortunately, the profession of telephone operator is almost extinct, not to mention that today he has to operate technically complex telephone systems that are not easily accessible to blind people. We probably don't need to talk any further about the telephone operator's career prospects. Many of the prejudices about the abilities and inabilities of blind people are based on such urban myths. I often read that blind people are particularly peaceful and patient. That sounds good, but it's poisonous praise; the downside of peacefulness is boringness and a lack of commitment.

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