Perception

What is Perception & how does it relate to language? • • • • • • Perception is many things to us. It is the here and now of our lives--the moment to moment awareness of our environment. It is the present, from which memories of the past and thoughts of the future are created by the brain. It is our reality! It is what happens to stimuli from the environment (eg.,kinetic or electro-magnetic energy) after they have been transduced into electro-chemical impulses within the brain. It is how they are organized by the Brain to give us any, if not the best chance of recognizing stimuli, particularly complex ones, such as speech or Sign Language. And still there is more. Look at the figure on the next slide. Can you see the lines clearly? For some of us, it may take a pair of glasses to achieve that crisp clarity, but with them we all can probably see them clearly. Seeing the lines is a matter of transduction, which we have been discussing at length. But now if I asked you to describe what you are seeing (or better yet to draw and color it), some difficulties might become apparent. Is there a problem and if so, what is it? Draw this figure and then try to color it in. Although the lines are clear enough, it will still be difficult to draw. Why? The answer is the difference between transduction and perception. The perceptual process involves brain structuring, and how it organizes incoming stimuli, determines what we experience. • • • • Although we can easily see this figure, it doesn't seem to stay put. I see three prongs and then all of a sudden there appears to be only two! The figure, of course, hasn't changed on the page. What we are experiencing is the perceptual process--brain reorganization. As the brain finds different ways structuring the stimuli, we experience different images! Structuring is far more comprehensive than you or I could have imagined. It is true that the images from the retina are carried pretty much in tact to the back of the head (the outer surfaces of the occipital lobes). But then, as they are brought deeper into the cerebral tissue, an amazing thing happens. The image is totally dismantled and disseminated to unknown areas of the brain. Horizontal and vertical lines, colors, shades and even motion itself is dissected out for distribution. The Brain is free to create our reality in just about anyway it wants. • • • • • Exactly how "reality" is brought back together is not known. No single location or clearinghouse has been identified in the brain which like a movie screen holds the ultimate image. Perhaps our illusion of cohesion in the world is analogous to the illusion of the power to move that is imparted to a puppet. In truth, it originates from strings that come from many other places (fingers). But what is fascinating about the brain is that it is free to choose the "strings" it uses; and even to add a few of its own to create our reality! When we discussed Mysak's model, we noted that there were two boxes provided for perception. One represented the structuring skills that are possible for us because of the nature of our particular central nervous system- a genetic (Species Specific) inheritance. The cat, for example, does not see the world the way we do. The other, represented the influence of past experiences, learning and our personal needs, to mention a few. There are two influences contributing to perceptual organization: innate brain structure and personal past experiences. • • • • • Both boxes of Mysak's model have the ability to add strings of their own in the brain's creation of our reality. Our understanding of these two sides of perception come from studies by the Gestaltists and the Behaviorists of past years. The Gelstalt psychologists, who stemmed mainly from Europe, took a natavistic or structural (Species Specific) view of perception. They used, by and large, a subjective approach in their research. They might, for example, stick a subject with an pin, and then ask him how he felt--what did he experience. They noted, among other things (but not from that fictitious experiment above), that more was achieved in perception that could be accounted for by the stimulus alone--an example of the -added string... I was talking about earlier. I have attempted to give a feeble demonstration of this phenomenon in the notes below. Try it at home. You will like it. In the final analysis, structure and experience interact to create our reality. • The Behaviorists, on the other hand (mostly centered in the United States), used an objective approach to their research. They might, for example, stick a subject with a pin and then measure how much he jumped or how loudly he yelled. • • • • They placed emphasis on the importance of past experiences to build up oneÅs perceptual skills. Not only were both schools of thought right, but equally important, to me, is the dynamic interaction that occurs between the two sides of perception. Although, I will discuss both independently, when I talk about the contribution of one, the influence of the other will always be evident. Focusing for the moment on the Gestaltists, they, using their subjective methods, teased out scores of ways in which our central nervous system automatically structures incoming impulses. LetÅs talk about three for now: The Best Figure Possible; Figure-ground and Closure. One innate perceptual process that effects our reality, is the creation of the Best Figure (image) Possible. • • The Best Figure Possible: The brain has an innate set of preferences directing how it organizes input. These have been referred to as the Laws of Pragnanz. They favor the creation of an image that has the qualities of any or all of the following: Simplicity, Symmetry, Proximity, Continuity, Similarity and others. I would like you to look at the following drawing and then answer the multiple choice question. If you answer it correctly you get an automatic "A" for this course* • WHAT DID I DRAW? Some innate perceptual processes that effect our reality, utilize the stimulus quality of Continuity and Similarity to organize the figure. • • If you answered B or D to the multiple choice question on the last page, you were RIGHT "perceptually"... but WRONG "pragmatically" in terms of what I had in mind. What I drew was an "M" perched on top of a "W." That, of course, would not typically be a person's first interpretation. That way of organizing the structure would run contrary to the quality of "Continuity." Here are some other examples of the Best Figure Possible. • • Similarity: Notice in the following figure that we tend to group the dots on the basis of similarity. This grouping behavior is important in developing the figure in many images. This principle is used in color blind tests too (see Notes). A third innate perceptual process that effects our reality, is the quality of Proximity. • • In color blind tests, dots of a particular color, embedded in a matrix of dots of various other colors, are arranged to form a number. If the client can see the color, they will perceive the number. If they are color blind, then the numbers will not be apparent. Proximity in time and space is another quality. In the following figure, note that grouping is automatically arranged on the basis of distance. • This has particular relevance to the reading process. In Old English words were once printed like this: o • "NOWISTHETIMEFORALLGOODMENTOCOMETOTHEAIDOFTH EIRCOURNTRYMEN." Not a pretty picture. Spaces make words stand out as units. • The same phrase, from the last slide, in later years, would have been printed with spaces between the words, so they would stand-out much more clearly. Let me repeat that phrase with spaces: o • "NOW IS THE TIME FOR ALL GOOD MEN TO COME TO THE AID OF THEIR COUNTRY." Here is another interesting example. Note that you must enlist the aid of the auditory modality and your knowledge of the units of spoken language to separate out the individual words in this list of sentences entitled, "When Fishermen Meet." Continuity is a powerful source of perceptual organization. o Continuity, as we have seen helps develop the best figure possible. Here is another example where continuity, or line of direction helps to bind separate units into a cohesive whole. • • In the next example, however, the quality of Continuity is even more compelling in its power to structure our image. In this figure the drive for continuity is so strong that we see something that is not there! Look at the figure, and then answer the multiple choice question.  This is a figure of...  A. A spiral  B. A circle  C. Concentric Circles  D. Concatenated Circles  E. None of the above. The Brain achieves Figure-Ground discrimination by focussing on some stimuli and suppressing others. • To me the answer to that last question is clearly "A." I always see a spiral. But I am always wrong! What we are looking at actually is "C," Concentric Circles. • • • • If you place your finger on one circle and trace it around, you will find that you come back to the same spot each time. Hence, physically, we can demonstrate that it is a circle. But the drive for Continuity is so great that we perceptually organize it and perceive it as a spiral. Figure-Ground Discrimination: The transducers despite their limitations, as we discussed earlier, convert more energy from the environment than the brain can handle at any point in time. The brain, however, engages in a separation of the input flow, whether it is visual, auditory or some other modality. Part of the input becomes the focus of attention. This is called the Figure. The rest is partially and sometimes totally suppressed from consciousness. This is the Ground or Background. The lowest level of perceptual organization is an awareness of the presence of the stimulus. • • • The Gestaltists, using their phenomenological approach to explore figure-ground discrimination. They would flash pictures before subjects at an increased shutter speed. They reasoned that as the exposure time was shortened, the perceptual process would not have time to be completed. Hence, the experiences of the subjects would represent the stages of perception. The Gestaltists identified four stages or levels of organization: 1. The Level of Awareness: When the stimulus is very brief, or very weak, we have only an awareness of its presence. When a person is not accustomed to using a modality, it is necessary to start training at this level of perception. o o • For example, if I have a hearing loss and acquire a hearing aid, I will need to practice first just being aware when the sound is present. The child may not produce a certain speech sound because he/she is unaware of the presence of the sound in words. Initial training procedures in these cases frequently involve making the child aware of the presence of the sound. 2. The Generic Level: As the stimulus gains in exposure time, or becomes stronger, or becomes more familiar to us, we begin to divide it up into a figure-ground structure. o o o The figure is weak, however, and we will "guess" at its identity often making wild errors across generic boundaries. For example, I was once jogging around my block one early morning before the sun had fully arose. As I came around my house, I noticed my neighbor (a 56 year woman) leaning up against the side of her garage. Although I thought it was strange, I kept on going for fear of losing any momentum I may have gained. I was a little surprised on my next round to see her still there. On the third round I resolved to stop and ask her if everything was alright. As I approached the garage, I was surprised to see that what I thought was my neighbor was actually a bush! Had I not examined more closely taking more time in better light, I would to this day think o o o o o o o I had seen my neighbor engaging in some rather eccentric behavior. I'm sure you all have had similar experiences where you looked at something and found it was something else quite different. But this brings up a very important point about perception. In the final analyses, it is always a guess by our brain as to what the the input is! Not only is it a guess, but it can and frequently is an incorrect guess, of which we often may not be aware. This happens at the Conceptual Level (for things we see/hear), and at the Symbolic level, for things people say or for things we read hastily. This tends to partly explain how reputable witnesses to an event can give very different accounts of its occurrence. 3. The Specific Level: At the Specific Level, the figure is accentuated against the ground and the range of guessing is narrower. The stimulus is more durable. When the stimulus lasts longer, or is stronger, the figure is strengthened in its definition, and the ground is muted even further. There is the illusion that the figure is actually placed "in front" of the ground. Examine the classic reversible figure-ground figure in the right column. Notice that if you make the white Chalice the figure, it appears to be in front of the black background; but if you make the two Faces the figure, they (in black shadow) appear to be in front of the white background. The range of guessing at the Specific level is much narrower than before. We might, for example confuse Mary for Betty, but not for a bush. Hence the percentage of right guesses is higher than at the generic level. 4. The Semantic Level: At the Semantic level, we have the "I know what it is feeling," and we are usually right, but it is still a guess. This is the level at which the stimulus is optimally available for decoding. It is exposed long enough, and it is strong enough. We usually have an immediate "I know what it is," feeling. o What we must realize, however, is that perception is still only a guess, and hence is not tantamount to realty. Although it is infrequent, the guess can still be wrong. Psychologists love to have unwitting subjects peer into the end of a box where they see the replica of a chair. o When they look in from the top, however, they realize that it is just a configuration of disjointed sticks. o • There are three types of figure-ground tasks: Masked Figures; Embedded Figures; and Reversible Figures. • 1. Masked Figures: Masked figures are hidden behind an irrelevant ground. The most famous Masked Figure, of course, was the Lone Ranger. He would wear a mask and no one would recognize him, until of course, he got on TV. On the radio it seemed to work fine. Above, in addition to the famous masked figure, is also a less dramatic but more germane figure-ground task. A screen is placed before the item. For you and I, the screen makes us work, perhaps a little harder and it may take a fraction of a second longer to identify the figure (a vacuum). But it is still easy to ignore the screen (ground) and concentrate on the significant lines. • • But for individuals with figure-ground discrimination problems, this could be an almost impossible task. They would look as much at the hash lines as the figure itself. The result is just a confusing meaningless morass of lines. 2. Embedded Figure-Ground: More common in our daily lives are embedded figure-ground tasks-- a looking for a needle in the haystack type of activity. o o o o • If I come into the classroom and there is just one person, I can pick him out immediately, but if the class is full (around 130 students) I may have a tough time even though he is in full view. When I was in the Air Force, I always procrastinated looking at the daily bulletin board because there were so many notes pasted up there-it was a pain to find the daily rosters. This did have some unpleasant consequences for me! In the following notes are a number of illustrations and comments about embedded figures. They are not only illustrations but suggestions for paper and pencil tasks that could be developed to improve figure-ground discrimination. Although perception has many innate qualities, it is amenable to improvement with practice. The tasks need only to be suited to the students age and interest; and arranged in difficulty from the simple to the complex so that success is the rule. 3. Reversible Figure-Ground: Reversible figures demonstrate the power of perception to change what we perceive. They are a fun type of figure ground task, and useful for demonstrating the power of perception. The three prong fork at the beginning of this session was one example of this. o What is so special about these figures, is that depending on how you organize it perceptually, may drastically alter what we ultimately experience. The illustration below nicely demonstrates that. o They say that," beauty is in the eye of the beholder." This is a very true commentary on perception. Note the sketch of my wife below, entitled "Before Six Beers," but brace yourself." This was done in the wilder days of my youth (65) when I used drink. o o Reality comes from perception, but perception is a sometimes thing!The picture below, "After Six Beers," is exactly the same picture as the one on the previous page. Only we have turned it upside down so that you will select a different set of reference points to create the figure that you perceive now. And the new figure you create is far different from the one you created before from the same picture! Reality, as experienced through the brain, is not as immutable as we would like to believe. • Following in the notes are a series of examples of assorted reversible figure ground tasks. Notice how, as a the brain automatically seeks different figure-ground organization, it creates different experiences for us from the same stimulus. Closure is a process of reconstructing the figure when pieces are missing, disjointed or distorted.    Closure: A point to be made with all this, is that you can't always hold up something before a child (or an adult) and say, "Don't you see it, it's right before your eyes!" Because we may all look at the same figure and see different things-or nothing, as we shall see in our discussion of closure. In many instances, the figure is incomplete. Pieces of it may be obliterated, or the figure may be disjointed, or it may be distorted. When this occurs, our brain tries to recreate it in a process called closure. There is a natural (innate) tendency to achieve closure . When it is relatively simple, the Laws of Pragnanz will guide the process. The figures on the next page are a good example of this. When the task becomes more complex, the factors of past experiences and learning become critical. Closure may fail to occur because of an organically based closure disability, but it could also be simply a lack of familiarity with the object. Filling in the dots involves the simplest kind of closure task.  The Laws of Pragnans will suffice to fill in the missing pieces of these figures. It is not necessary to be familiar with the figure to match them with a criteria (eg., the full figure on the right). All of the other examples presented on the next page in the following Notes require an increasing degree of familiarity with the stimulus. Filling in larger areas of the figure requires in addition to innate ability, a history of experience with the objects.   In these figures below, closure is possible only if you have had experiences with these items. With books and TV being so available in our culture it is hard to imagine very many who have not had this exposure. But there are some children from severely poor rural and urban communities who are lacking in these experiences. In the Notes below are additional examples of Closure tasks and some comments on them. Perception is a PROCESS which takes TIME and if it takes too much time, speech and language may be affected.     Another important feature about perception, which the Gestaltists demonstrated when they reduced the exposure time of the stimulus is that perception is a PROCESS. The brain is doing something with the impulse flow and it requires TIME. That is something we lose sight of in our daily lives. We look, hear and feel things and have what seems like instant recognition. It is rare that we have to peer to see or strain to hear something, but when we do, it typically takes longer. If we have the time to wait, we can finish the processing and understand what was transduced with no harm done. But sometimes the stimulus is transient-lasting only a fraction of a second. There is no second change. Speech is this way. We hear it and it is gone, only to be immediately replaced by another string of words, which themselves are very fleeting. This reminds me of dictation tests I have had to struggle with. The perceptual speed of children and older adults is frequently slow enough to cause problems in understanding language.       For speech, if the perceptual processes are too slow, the listener may not partially or fully comprehend what was said. You see this with three year old children all the time. An adult may ask a child to do something, like bring the doll, and become frustrated when the child fails to respond. The adult might even walk away, and miss the childÅs response that comes late when the perceptual process is finally completed. You may have experienced this in the Figure-Ground and Closure tasks presented in the Notes. It may have taken you minutes to see the Old or Young Lady (reversible figure ground tasks), or the bearded face (closure). Hence, if the perceptual process is too slow, language, speech development and/or the ability to engage in verbal conversations may be seriously impaired. What makes it worse is that the cause of the problem is not so readily recognizable. It's usually clear when someone has a visual or hearing impairment (transduction), but few people recognize or understand perception problems. Perceptual problems in children and adults are typically misdiagnosed as other more common disabilities.     When a child has perceptual problems, their lack of language and speech is frequently attributed to other factors such as retardation, laziness, a lack of motivation, or a neuroses, etc. This can happen to those of us at the other end of the age continuum too. I mentioned earlier that on a good day (when I havenÅt been breathing too much bus fumes, or consuming too much lead from our water faucets or canned foods, or starving my neurons with the plethora of highly processed nutritionless foods that are on the market) I may loose 10,000 neurons a day. If I was lucky to be born with a hundred billion, I can go quite a few days with little effect. But if I had less to start with, and/or live long enough, in time there may be less neural structure to fully support these perceptual processes. They will still function, but they may take increasingly longer to come reach a completion. Hence, I may find that life around me seems to grow more and more confusing. An inability to perceptually organize a figure leads to confusion and/or incorrect recognition.     There are five possible outcomes of the perceptual process: 1. An inability to organize (and recognize) the stimulus. When this occurs, the outcome is total confusion or a incorrect guess. In the picture of the bearded face, for example, many students see only splotches of black and white. Others see erroneous pieces of odd shapes such as rabbits, sheep etc. I always see images of Marilyn Monroe. 2. An inability to organize the stimulus in a timely fashion. When this occurs recognition is achieved but it may come too late to be useful. This was always my experience in my beginning Russian class during our vocabulary dictation tests. On a dictation tests we often feel we could do much better if we were given more time between words. (Please don't ask me if I can speak Russian. All I ever was able to do was ask where the bathroom was, and that with a heavy English drawl in distorted Russian phonemes. In the time it would take any Russian listener to close in on that message, I would find myself in deep trouble)! 3. Organization is achieved in a timely manner but the figure can not be   reorganized. You may have experienced this in the reversible figure ground task involving the old verses the young lady. Once you were able to see the one, you may have found it difficult to switch back (reorganize your figure ground) to see the other. This is sometimes referred to as Stimulus Bound. This rigidity, on a larger scale, is reminiscent of the perseverative behavior exhibited on the motor level by some individuals with brain pathologies. Once they get a motor set, they cannot stop the activity. 4. Organization is achieved in a timely manner but the figure is incorrect! This is particularly likely to occur, as we shall see later, when the behavioral factor of expectations become involved. The saying that " We see what we want to see," is very germane here. 5. Organization is achieved correctly in a timely manner and can be quickly switched. This, of course, is where we would like to be all the time. Ironically, language, which depends upon perception for its development, later assists perception by facilit So how does perception work? Take a look at the object below. Now please continue and we will come back to this later.  Messages contain information and redundancy    There are two parts to a signal conveying a message: information and redundancy. Information we all know about. It's the stuff knowledge is made of. Redundancy is that part of the signal that increases the the chances for the message being understood. There is a trade-off here. The more redundancy there is in a message, the less information is transmitted, but the chances of being understood are improved.   On the other hand, if there is much information, the chanced of having it understood are decreased. Repetition, concepts and rules, particularly Grammar, are sources of redundancy in a message.     What are some examples of redundancy? A classic is repetition. In the following message... What do you think the fifth letter is? There is not much information in that line but it is easily decoded as "A," thanks to the high factor of redundancy (repetition). On the other hand, what is the fifth letter in this line? It's not as easy, but there is more to gain in the line. Another source of redundancy are rules. Try this one‡    One important source of rules is GRAMMAR. Try this sentence: You probably easily guessed the first word was "The." But think of all the three letter words you know. You ignored most of them because you know the rule in English..a word before the noun is usually a determiner. Perception is an internal source of redundancy that reduces the range of guesses the brain must make.     There are only a few determiners to choose from. Concepts also provide redundancy. What is the last word in the following sentence? Although there is little left of the last word, our knowledge of monkeys and what they eat would probably lead us to easily decode it as "banana," and not "bacon." Remembering that perception is always a process of guessing, notice what redundancy does. It acts to reduce the range of the guesses we must make to recognize the input.    Language develops through the processes of perception, but in turn facilitates the process of perception.   What perception does, itself is to provide an internal source of redundancy. Figure ground reduces the range of guessing by reducing the stimuli we must process; closure fills in many pieces to make a single cohesive whole; the best figure possible simplifies the figure etc. etc. Can you recall the figure on Slide 30? Pragmatically it was a circle, but not really. It was many disjointed dots and some other short lines. But perceptually, you filled in the many little dots in the periphery to image the circle. Vygotsky demonstrated that the mere process of attaching a name to a pattern made it easier to recognize later. You may notice that children with good vocabularies seem to be unusually aware of the detail in their environment. It's a case of the "rich get richer." Good perception facilitates language development, but language development facilitates good perception. Children with perceptual problems must work harder to get less information from the environment.  By filling in the dots you didn't have to deal with each one individually--a    horrendous task. You probably ignored also (included in the ground) the small lines in the interior. Hence, they didn't require such intense processing. For those children whose perceptual processes are less efficient, the world is a much busier place. Unfortunately much of the "busy" stimuli is worthless and consuming in terms of both energy and time. The examples we have given here were mostly visual (because that is easier to present in this media) but the perceptual principles underlying them apply equally well to all modalities. In the next section we will zero in on some of the perceptual skills that are particularly important in the Visual Modality alone.