Sensory Integration

In order for a child to appropriately move through space and interact with their world in an alert, regulated, effective and effortless manner, they must take in an extraordinary amount of sensory information, unconsciously interpret it and then make appropriate adaptive responses on a rapid and continuous basis. This is an incredibly complex process that relies on an intricate network of sensory systems functioning appropriately and simultaneously. It’s an amazing process that most of us take for granted; it just happens and we never think twice about it. Unfortunately, for many of the children we work with, this is not the case.

For a child with sensory integration dysfunction, the seemingly simple task of moving across a classroom, putting on a t-shirt, copying from a board, finding a toy in a closet, listening to mom on a busy street, walking barefoot on a beach, or playing in a swing in the park may be interpreted as impossible/daunting or terrifying. Sensory integration dysfunction can impact every aspect of development including: gross and fine motor, adaptive and self-help, speech and language, social-emotional, behavioral, attention and regulation, visual motor, visual spatial, perceptual and academic.

Our ability to make sense of the space around us and appropriately meet the many challenges faced in our daily lives is a result of the integration and proper “wiring” of five major sensory systems: vestibular, proprioceptive, tactile, auditory and visual.
The vestibular system is located in the inner ear and is the integral system that responds to gravitational forces and changes in the head’s position in space. The vestibular system is so important and it’s function so widespread, that it is strategically protected inside a boney structure surrounding the inner ear. It is the sense that tells you when you’re right side up or upside down, when you’re moving toward a target, and is responsible for helping with balance and spatial orientation. The vestibular system is also responsible for proving a stable basis for visual function, even when the head is moving through space. Also, when an object is getting larger in your visual field, your vestibular confirms that you are not moving, thus indicating that the object is coming toward you. The appropriate response can then be made, whether it’s to move out of the way or catch it.

Movement is a component of almost everything that we do; so vestibular function applies to almost every interaction we have with the world. It’s the sense that, when over stimulated, makes one feel seasick and carsick. It’s the sense that thrill seekers try to satiate with roller coasters, bungee jumping and skydiving. Because of it’s role in movement and space, it works hand in hand with the auditory and visual systems in order to provide us with a sense of our three dimensional spatial envelope, the foundation for visual spatial skills, and the awareness of our surroundings that compels us to move and explore. This collaborative system is often referred to as the vestibular-visual-auditory triad.

“Without a properly functioning vestibular system, sights and sounds in the environment do not make sense – they are only isolated pieces of information disconnected from the meaningful whole. It is the integration of the sensory information that holds the key for finding the meaning in the world. Because movement is part of everything we do in life, it could be said that the vestibular system supports all behavior and acquisition of skills, as well as helping to balance the stream of sensory information that constantly bombards the system.” (Astronaut Training: A Sound Activated Vestibular-Visual Protocol for Moving, Looking and Listening; Kawar, Frick & Frick, 2005)

The vestibular system also works very closely with the proprioceptive system.

The proprioceptive system is a network of sensors throughout our muscles and joints that work together to create an internal body map. It is through our proprioceptive awareness that we know the position of a body part, even when we cannot see it. For example, if we were to close our eyes and have one of our arms positioned by someone else, we would be able to place our other arm in the relatively exact same position without looking. We know the general position of our body at all times because of the feedback received from our proprioceptors. It is with intact proprioception that we can navigate a dark, familiar environment, or reach and grab something behind us without looking. It is also the sense that grades our pressure, allowing us to use the appropriate force when picking up a brick versus a paper cup of water.

Because of its role in providing us with a sense of our bodies, the proprioceptive systems response to input received through passive deep pressure, and more importantly, deep muscle activation, can be very grounding and organizing to a child. It is difficult to feel secure in oneself or in ones environment without possessing a strong sense of body scheme. The proprioceptive system collaborates with the closely associated tactile system to provide us with the critical sense of body awareness.

The tactile system is made up of the largest organ of our body, the skin. It is the system that provides us with the sense of touch for pleasure, pain, discrimination and protection. Each area of skin on the body has specific characteristics of tactile function in order to support the associated functions. For example, the tactile processes of the fingertips are far different from those of the back. The fingertips are designed to explore our surroundings with strong discriminatory function. They can easily determine the difference between two textures, subtle changes in temperature, and identify small objects by touch alone. The tactile receptors in the back do not support such complex function.

Being that the tactile system is our exterior boundary, it is crucial that it appropriately processes the wide variety of elements and touch sensations that surround us. If dysfunctional, pleasurable touch can be misinterpreted as noxious, and potentially dangerous sensations can be unregistered and damaging.

Each of these systems must function properly and harmoniously in order to support appropriate sensory integration. A typical sensory system can process a wide variety, and range of intensity, of information and make the necessary filtrations and adaptations in order for a person to function comfortably and without conscious effort. However, with many of the children that we work with, we find that one or more of these systems does not function properly. Any of the sensory systems can be over-reactive to incoming information (hyper-responsive) or under-reactive (hypo-responsive). They may either register the incoming sensory input but ineffectively interpret, or modulate it; or they may insufficiently register, or orient to, the incoming sensory input.

This can be easily explained with an example of the tactile system. A child with a hyper-responsive tactile system may avoid messy play and unfamiliar textures and objects, may hold objects in their finger tips, avoiding contact with palms, may need to remove tags from shirts and only wear soft old clothes, may avoid standing close to peers and other people, may resist cuddling and affection even from parents and family, may present with poor body awareness and delayed movement patterns and motor planning, and may tend to be inflexible and rigid in their ways in an effort to attempt to control a world that is perceived as threatening.

A child with a hypo-responsive tactile system may seek out messy and unfamiliar textures and objects in an effort to better process their bodies and the things around them, may not seem to notice or mind when socks or clothing articles are twisted in uncomfortable ways or when sticky food is on their hands or face, may frequently bump into others or play excessively rough without ill intentions, and like their counterparts, may also present with poor body awareness and delayed movement patterns and motor planning, and may tend to be inflexible and rigid in their ways in an effort to make sense of a world that they have great difficulty processing.

Sensory integration was originally founded by occupational therapist, Dr Jean Ayres in the 60’s. It is a dynamic, child-directed treatment approach based on specific principles, treatment techniques and equipment, and styles of interaction. It is a problem solving and individualized approach that requires ongoing analysis and assessment in order to monitor changes in the child and adapt the treatment accordingly. A trained sensory integration therapist utilizes a wide range of techniques and strategies to provide children with the therapeutic environments and opportunities to improve responses to incoming sensory information, thus enabling them to become more confident, successful and interactive explorers of their worlds.