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Valerie Dejean
writes on Vestibular Dysfunction

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The person may appear floppy, not sit up straight, or their joints may appear hyper-flexible. All refined movements of the extremities and head are dependent on an adequate base of muscle tone to provide postural support. A lack of sufficient postural support can contribute significantly to difficulties in controlled movement of our limbs and tongue. This results in difficulties in gross, fine and oral motor coordination.



What is Sensory Integration?
 By Valerie Dejean
 Director, Spectrum Communication Center and Certified Tomatis Consultant

Sensory integration is the ability to receive information from the senses, combine it with prior information, memories, and knowledge, and use that interpreted information to respond appropriately. This responding appropriately is referred to as an "adaptive response". Through the process of normal interactions with the environment the individual's brain constantly receive sensory input from the body; the ears constantly hear external and internal sounds, the skin receives constant sensory messages from the air and clothes, gravity a constant force that the individual must always orient to, and the eyes (while open) continually adapt to what is in their line of vision.


 These sensory messages are, in essence, "food for the brain:" the brain needs sensory input in order to function and thrive. Sensory Registration and Regulation. The first level of sensory integration is the ability to take in the sensory information and adjust to it. We refer to this as sensory registration and self-regulation. Initially a baby reacts to sensory stimulation in a total and often defensive manner. For example, a baby's whole body will startle to a loud sound or withdraw from an unexpected touch. This is the early "fight or flight" response that needs to be modified in order to respond "adaptively". The baby learns to discriminate whether the stimuli imposes a danger, or rather is something to be attended to and enjoyed. As the baby's brain matures and he is more accurately able to register and regulate his responses he enters a state of calm alertness, from which he can learn from his environment.

Sensory Registration: Reactivity (Thresholds)

A child's ability to register and regulate his response to sensory input can be either over-reactive (what we refer to as having low thresholds for sensory input, as described in the last paragraph), or under-reactive, (the child with high thresholds, who poorly registers sensory input). This might be the child who you have to call five times before getting his attention. More often we see a mixed profile; the child, for example, who seems oblivious to pain yet is bothered by every little noise. It can sometimes be confusing, for example a child that has such over-reactivity (low thresholds) to either touch or sound that they become overwhelmed, shutting down and consequently presenting as a child who is not reacting or registering the sensory input. This is important for the listening staff at the Spectrum Communication Center to distinguish, because when the training starts to "open up" the sensory systems of such children, they can appear as if they have swung to the other extreme.

 An example of this is a child with such extreme auditory sensitivities that he shuts down and therefore his auditory system is not available to discriminate and learn language. During training it is observed that, though the child is now starting to discriminate sounds and develop language, he also at the same time is demonstrating sound sensitivity. The truth is he was always sensitive to sound; he had just closed off this system in order to protect himself. The training didn't cause the sound sensitivities, but rather uncovered them as we "opened up" the auditory sufficiently for this child to attend to speech sounds. We can now address the sound sensitivity that caused him to shut down in the first place. There are many variations of how the different sensory thresholds interact, and it takes careful study to determine the patterns that exist in each child.

Sensory Regulation:

Registration and regulation operate on a scale with low thresholds and high thresholds on either end, and with self-regulation the homeostatic midpoint. It is in the balance between over-reactivity (low thresholds) and under-reactivity (high thresholds) that we are well regulated. In order for a baby, child, or for that matter anyone to be optimally available for learning, they should be in this "quiet alert" state of regulation. If one is over reactive to touch for example and is focused on the tightness of his belt or the seams in his socks, his sensory system is not available to discriminate what the teacher is saying. Or a child may be unavailable for learning because he is so under-reactive to sound that he drifts off unless the conversation is highly animated. This lack of balance between low and high thresholds can be observed in a number of conditions from Autism, PDD, ADD, and auditory processing disorders.

By contrast, just think of the well-rested baby who awakes for his nap ready to take in the world.
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his is the starting point of all leaning and it requires the registration and regulation of sensory input. Sensory Integration: After children are able to register and regulate their responses to sensory stimuli they must put these separate pieces of information into a meaningful whole. This is what is referred to, as "Sensory Integration." The period from birth to eighteen months is a period of massive sensory integration where babies learn about the physical reality of the world through their senses. From their sensorimotor experiences they develop perceptual constructs of the world. The reality that they form based in large part upon the accuracy of their sensory integration, becomes the platform from which they interact and communicate with their environment.

For example, when we eat an orange, we have a total sensory experience. We sense the orange through our eyes, (we see it), ears (the sound of the skin peeling), mouth (the taste), and skin (on our hands and fingers and in our mouth). We also receive information from less conscious sensory systems that tell us the exact position of our hand, how wide we open our mouth, how hard to bite down, how much to move our head to our hand, etc. Sensory integration allows us to put together all the needed sensory information to experience eating an orange. If we have misinformation (poor sensory integration) then we have a faulty picture of the world.

How Does Sensory Integration Relate to My Child?

In a well-functioning brain, messages from the central nervous system reach their optimal destination in the brain and are responded to. However, in some individuals, sensory messages are misinterpreted, intensified, or omitted, which, in turn, does not allow the brain to respond appropriately. A. Jean Ayres, Occupational Therapist and creator of Sensory Integration Theory, asserts that the primary building blocks of the central nervous system are the senses, particularly the special senses - vestibular, tactile, and proprioceptive. All other skills are complex processes based on a strong foundation of sensory integration. In Ayres book, Sensory Integration and the Child, she likens sensory integration disorder to a large city in which traffic consists of neural impulses. "Good sensory processing enables all the impulses to flow easily and reach their destination quickly. Sensory integration dysfunction is a sort of "traffic jam'" in the brain.


 Some bits of sensory information get "tied up in traffic,' and certain parts of the brain do not get the sensory information they need to do their jobs." (Ayres, Sensory Integration and the Child, page 51) How the Senses Interact Special Senses- The Vestibular System (Somatic Integrator) Both Dr. Alfred A. Tomatis and Dr. A. Jean Ayres emphasized the importance of the vestibular system in the inter-relatedness of the senses.

The vestibular system is part of the inner ear and its job is to detect motion and gravity, and provides us with our sense of balance. It tells us where we are in space. The vestibular system is a very old sensory system and was the first sensory system to develop on this planet. We needed to know whether we were up or down before we needed to see, hear, taste, touch or smell. The vestibular system is the first sensory system to develop in the womb, and starts to develop when the fetus is only two weeks old. It is fully formed and starting to function in the womb by 4 and 1/2 months gestation. Because of this early development the vestibular system has many connections with the rest of the brain, which develops around it; consequently it is believed to provide the foundation for many other functions.


When the influences of vestibular stimuli fail to reach their natural destinations, they cannot adequately contribute to sensory integration. One of the functions that is particularly influenced by the vestibular system is a person's muscle tone. Muscle tone is the normal level of muscular tension that exists when the body is at rest yet ready for action. The vestibular system particularly influences the muscle tone that helps us resist the influence of gravity. Gravity is always pulling us to the ground and if muscle tone is decreased, it is more difficult to initiate movement or to maintain muscle tension during movement.

The person may appear floppy, not sit up straight, or their joints may appear hyper-flexible. All refined movements of the extremities and head are dependent on an adequate base of muscle tone to provide postural support. A lack of sufficient postural support can contribute significantly to difficulties in controlled movement of our limbs and tongue. This results in difficulties in gross, fine and oral motor coordination. Bilateral coordination is another function particularly influenced by the vestibular system. It provides the opportunity for the two sides of the body to communicate with each other at the level of the brain stem via the vestibular nuclei. In this manner it supports the ability of the body to use both sides in a coordinated manner. We see this initially when the baby starts to develop equilibrium reactions where one side of the body responds differently yet in a coordinated manner with the other side of the body.

From this activity the baby develops a sense of where his center is, and then how to move around it (rotation), and across it (crossing midline). This awareness provides the foundation for the development of laterality (sometimes incorrectly referred to as dominance), and for the specialization of skills on each side of the body. Many of our advanced human skills, such as language, are dependent on a good foundation of lateralization and specialization. The tactile system, our sense of touch is a sensory system that develops very early and therefore has the opportunity to influence the developing brain.

Tomatis viewed the skin as part of the vestibular (somatic) integrator because the tissue that goes on to become the skin in the developing fetus emerges from the tissue that forms the ear. The tactile system starts to develop soon after the vestibular system, and it is the only sensory system that is fully functional at birth. As soon as a baby can move, he reaches out to the world through his sense of touch. The mouth and the hands are both very rich in tactile receptors and consequently are the primary tools the baby uses to explore the world; consequently everything is put in his mouth. The more accurate the information the baby receives from his sense of touch, the more accurate his internalized picture of the world will be. We call this internalized picture, our body map or body schema.

 Sensory information is registered from the body and organized into neuronal models, which are replications of the environment and our mechanical selves. The vestibular, tactile, and proprioceptive (information about our body position from our muscles and joints) systems enable an individual to develop an understanding of self. We need a "self" and a "non-self" in order to interact with and understand the world around us. The vestibular system of the inner ear plays a major role in integrating the information from these other senses and putting it all together into a meaningful whole.

Dr. A. A. Tomatis described this role as the vestibular integrator. Good sensory perception is important in the development of accurate neuronal body models or rather body schema. The Distance Receptors: Seeing (vision) and Hearing (audition) So far in discussing the vestibular integrator we have been talking about experiences that are either within our body, in contact with our body, or have to do with how our body relates to the environment. We feel something when it touches us and we are constantly adjusting our bodies to the force of gravity. When it comes to vision and hearing we have a different experience. We see and hear things outside our bodies, and we refer to these sensory systems as external or distance receptors. We hear or see things from a distance; it does not have to come in contact with the body. Sensory information from the visual and auditory systems has to be integrated with the other senses and this is again accomplished through the vestibular system.

Visual Integrator Vision involves the mechanical reception of light, and visual perception is how we interpret that information. Dr. A. A. Tomatis referred to the visual integrator as the mechanism for integrating visual information from the eyes with vestibular information from the body. The vestibular system has a direct and very fast connection with the eyes. This allows the individual to quickly detect whether he or the environment is moving. Have you ever had the experience of sitting on a train stopped in the station next to another train? As the other train starts to pull out, you experience a moment of anxiety as your body tells you that you are motionless, yet your eyes tell you that you are moving. In that instance you have a sensory mismatch, and it is a good example for how these two systems are always referencing back and forth between each other. This vestibular-visual integration is very important developmentally because a baby starts to attach meaning to his visual environment via this double-checking with the vestibular system.

 The baby starts to recognize that it is the same rattle whether he is lying down or sitting up. He recognizes that objects are the same no matter which way they are flipped. He starts to know if he is to the left, right, over, under, in front of, or behind an object, as well as how these objects relate to him, long before he knows the words for these orientations. In fact it is hard to learn the words for these prepositions if you don't "get" the physical experience of these positions through good vestibular-visual integration. The vestibular system provides the foundation for accurately interpreting information from our visual field. Therefore it has a major impact on the development of visual perception.

People who have been blind since birth and regain their vision, are completely overwhelmed by what they see because their brain doesn't know how to make sense out of it. Developmentally the visual system depends on the vestibular system to make sense out of what one sees. Space perception (where we are in space/directionality), visual perception (spatial orientation of object and symbols such as letters), and even linguistic concepts of prepositions, are end products of sensory integration that are dependent upon good vestibular-visual integration.

Cochlear (Linguistic) Integrator Dr. A. A. Tomatis distinguished between hearing, which he described as the passive reception of sound, and listening, which he described as the active ability, intention, and desire to focus on sounds. This is similar to how we distinguished between sight and visual perception. It is possible, and even likely to have normal hearing, yet have poor listening. A child may be able to hear a pin drop from across the room, yet not be able to attend and listen to what is being said to him. The vestibular system and the cochlear, the part of the ear that analyses sound, are anatomically joined and form what we call the inner ear. The VIII cranial nerve carries sensory information to the brain from both the balance and hearing parts of the inner ear.

The auditory and vestibular systems lie closely together throughout the nervous system. This allows for much opportunity for sensory integration between the vestibular and auditory systems. Sensory integration disorders that involve vestibular processing can impact the area of speech and language development.

 Research has found that therapy aimed to improve the function of the vestibular system can also result in improved language. Dr. A. A. Tomatis discovered that faulty sensory information from the ear could affect vocal output. The concept that the voice can only produce what the ear can hear was known as the "Tomatis Effect". When children mishear sounds, they will misarticulate them also. This can have a significant impact on speech development. Faulty sensory information can also affect auditory perception. The auditory system is required to interpret all the sounds of spoken language and attach linguistic meaning to them. For example, a dog is able to hear as well or better than humans; however the dog's ear isn't able to separate the speech stream into meaningful words that he can understand. This requires auditory perception and auditory processing. Together they provide the foundation for understanding languages spoken or written.

When we mishear sound through faulty perception and processing, we have difficulty attaching these sounds to the visual symbols for them (letters). Because we mishear the sounds we then misspell them. So problems with reading and writing can be associated with an auditory problem, not just a visual problem. Although we separate auditory perception and processing for diagnostic reasons we often refer to difficulties with them under the single title of "auditory processing disorders." Auditory processing disorders are often related to a disorder of processing within the vestibular system and to difficulties in integrating sensory information between the vestibular and auditory systems. The auditory system needs the stable base provided by the vestibular system in order to process information. Much like the visual system, which has to reference what it sees through the vestibular system, the auditory system also must perform a similar reference. Without stability from the vestibular system, it is difficult for the auditory system to accurately interpret the sound stream. This topic is covered in more detail in the handout entitled "Auditory Processing and the Tomatis Method."

Motor Planning & Praxis

Motor planning is the next level of sensory integration that is imposed on a foundation of sensory registration and regulation, and sensory integration and body schema. Praxis is the ability to self-organize. It is the ability of the brain to conceive, organize, and carry out a sequence of unfamiliar actions. Dyspraxia means a reduced ability to carry out non-learned movements, despite adequate motor and conceptual capacity. Praxis is believed to be a single function involving several basic processes. The first is ideation or generating an idea of how one might interact with the environment. Next is the organization of a program of action that includes the correct sequence and timing of the steps involved.

 This is the process most accurately referred to as motor planning. The final process is the execution or the actual performance of a motor act. We need praxis in order to develop higher-level skills. It is after the infant moves beyond the "hard wired" functions of sitting, standing, walking and babbling that praxis is called upon. These innate functions occur without praxis. Once the baby moves from sensory motor play (banging the rattle) to more purposeful play (putting the rattle into a cup), he starts to rely more on praxis. He needs to have and idea (ideation) of what he wants to do; he needs to have a plan (organization) of how he will sequence and time his movements; and finally he needs to perform (execute) the action. When we have adequate praxis for successful behavior, we can adapt effectively to our environment.

The better the baby is able to do this, the more successful, or adaptive, his interactions will be. It is through successful sensory motor interactions that we develop responses that lead to further and more advanced interactions with our environment. All of this, of course, is dependent upon good sensory integration and a good body schema.

How Can the Spectrum Communication Center Help? At the Spectrum Communication Center we have been using the Tomatis Method of "listening training" since 1992. The Spectrum Communication Center pioneered using Tomatis's developmental theories in conjunction with the sensory integration theories of Dr. A. Jean Ayres, in what we have called the Spectrum Communication Center Method.

Through this unique perspective we create an individualized program for each client that enable him or her to overcome communication, behavioral, organizational or learning difficulties. The Listening Training program offered at the Spectrum Communication Center can help individuals with Sensory Integration Disorders by making it easier for them to process and integrate sensory information. By helping these children reach a more regulated state of calm alertness they become more available for learning. Children whose systems have been striving to shut out sensory stimulation become more relaxed and better able to connect to those around them. Most children with Sensory Integration Disorder are working much harder than their peers to accomplish the same things. There is a tremendous experience of relief as things become easier, leading to an improved sense of self-esteem. Their bodies are now able to keep up with the things their brains are able to conceptualize.

 If you have a child with Sensory Integration Disorder, call the Spectrum Tomates Center at (845) 915-3288 to discuss your situation or schedule an initial evaluation. Copyright 2010 Vestibulum



 

  An example of this is a child with such extreme auditory sensitivities that he shuts down and therefore his auditory system is not available to discriminate and learn language. During training it is observed that, though the child is now starting to discriminate sounds and develop language, he also at the same time is demonstrating sound sensitivity. The truth is he was always sensitive to sound; he had just closed off this system in order to protect himself. The training didn't cause the sound sensitivities, but rather uncovered them as we "opened up" the auditory sufficiently for this child to attend to speech sounds. We can now address the sound sensitivity that caused him to shut down in the first place. There are many variations of how the different sensory thresholds interact, and it takes careful study to determine the patterns that exist in each child.
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