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Behavioral Optometry BOAF
Volume1 Number1 2012
cusing on only a small amount of the input from our sense organs, we can attend to faint input from clearer information when required. For example, we are involved in a conversation at a party and a more interesting discussion across the room catches our ear, we can filter out the detailed in- formation of the close conversation and focus more on the one taking place farther away. Our ability to disregard irrelevant input is essential; without it, we would constantly be on full alert. This is why a person might startle on hearing the unex- pected crash of material, but only the first time. An experienced doctor is able to ignore much of the detail on a scan, honing in only on what is relevant. And that is often the keyword, what is relevant in a person's world. What is the problem? Is it the de- tail or the surroundings? The brain finds it hard to stop perceiving, so when deprived of sensory input it tends to create its own. In early stages of blind- ness, for example, people can suffer from halluci- nations of varying intensities. Sensory deprivation can be deliberately induced in relaxation devices known as "floatation tanks", in which people lie in warm saltwater in complete silence and darkness. This pleasant experience may cause mild halluci- nations. However, sensory deprivation can be used as a form of torture.
Although the world frequently presents us with too much information, it can also provide us with too little. Experience enables us to fill in informa- tion gaps in much the same way as it helps us to focus our attention when we are bombarded with vast quantities of irrelevant sensory input. There are many things out there that we need to be aware of, yet only tiny hints of their presence may exist; our brains must pull together fragments of information from all of our senses in order to detect these things. In a jungle, for example, we might hear twigs breaking underfoot and see a flutter of movement and a blur yellow in the leaves. From these clues, all of a sudden we may perceive a tiger hidden amongst the greenery. In fact, humans are programmed to find links between information in the world even when they do not actually exist, the theory being that it is better to detect some- thing in error than to fail to identify a hidden dan-
ger. Whenever we look at a person, an object, or a scene, our brains instantly distill all the detail into a small number of categories. We see a house, for example, which is composed of windows and doors,and if we look closer we may see door han- dles, keyholes, and letterboxes. While we can rec- ognize that each object is a different color or shape, this unnecessary level of detail is quickly stripped away. In other words, if all we want to do is open a door, we do not need to register its color. We simply need to recognize that it is a door. This process of categorization is also essential to speech perception. People perceive clear conso- nants even though they are often blurred by sur- rounding sounds. Without this ability we would never make sense of spoken language. In similar way, we tag some of our life experiences as "famil- iar", perceiving certain people, things, and places as emotionally closer than others. We can say, we are learning through life.
The learning process occurs as a result of ex- perience and it pervades our lives. We learn to ig- nore unimportant things, such as the drone of the traffic or the color of the office walls, and to predict predictable things. Like the fact that a car driving through a puddle will splash us if we stand too close to the curb. In general, we learn how to make good things happen to us and how to avoid things that could harm us. Memory is absolutely essential to learning. Without this capacity, we would have to learn the same things over and over again every day of our lives. However, we can only retain a small proportion of vast quantity of information processed by the brain. The Major challenge for babies and young children is to get to know the world around them. There are new things to learn, and older people can actually pick up a lot from the young. We have an amazing ability to associate experiences, sensations, objects, and events. This is the basis of most learning.
When learning to read, a child must associate written script with the spoken language he or she has begun to master. Conditioning is one way we learn direct relationships between two events. That
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