Vestibular-another sense of where we are in space:
Most of what we do is based on how we feel, emotions and the overall feeling of our bodies. Nausea can also come easy to some people by way of motion. The vestibular sense in our ears that communicates to our brains tells us movement of our body, up or down, left or right.
Our ears are a 2 for one mechanical device. Inside the cochlea is a water like substance. When we move our head the water moves and the tiny hairs in the cochlea also move and transmit the direction and force to our brains. The hairs on our arms can tell us when we are brushing up against something, or the direction of the wind. The hairs on our heads also are good for information, we are usually can feel if they are being pulled even a little or styled in a way that is comfortable. The hairs in our cochlea are much more sensitive to movement.
For SPD kids, movement is the center of their worlds. We have kids who move all the time, and others who hardly get off course. There are times that the brain is looking for more external information. It is continually processing incoming information, and the vestibular system needs lots of checking in as well. During times of sensory incompatibility, this sense is needed more and the communication becomes a top priority.
Those kids who like to, rather need to, move are checking in with their vestibular system all the time. Just turning their head is a whisper from their vestibular system. The brain can hardly pinpoint the head’s placement with such mild movements and requests more. Running, jumping, sliding and spinning are needed, even in the classroom. These movements can be a danger, so they find other ways, leaning back in chairs or sitting sideways, rocking back and forth, basically any large body movement gives the messages in stronger force and higher frequency and incorporates vestibular sense’s best friends- proprioception, vision and hearing.
Have you ever been in a car and thought your car was moving forward when in fact the car next to you was backing up, this can create dizziness without actual movement of your body, sensory incompatibility. The eyes give us our horizon, the floor and ceiling to tell us where we are in relation to our surrounding. Our hearing takes in sound from around our heads for location of objects and people, even danger. Proprioception tells us how hard to move against gravity, what the floor is like and if we are sitting, standing or walking (or running, jumping, sliding . . .) and spinning! Our vestibular system tells our body what position it is.
Moving kids are just researching space, getting to know their place in history of the moment. Not knowing this is sensory incompatibility.
Most people have a preference for direction of spinning (if you can tolerate spinning). The opposite direction tends to make us dizzier more quickly. Our brains can ignore the spinning in one direction more than the other. Children with SPD tend to spin in one direction and will dislike the opposite direction. This is true of other ways of vestibular input. They might prefer swinging, or running, or sliding. Some kids even like them all; this is what they crave, what their body is asking of them and what the need!
Though some don’t need. They don’t need movement, they rather avoid movement, their sensory incompatibility is movement. Their brain is processing vestibular information too much, giving it too high a priority. They avoid running and spinning and sliding and hate riding in the car. They will not be standing in line for the rollercoaster or be excited about climbing a tower. These children like to stay on solid ground, even a small amount of height might be unsettling. Their visual perception and vestibular information is too much, their proprioception is unstable and leads to fear of falling.
This is very real to them, they have an unrealistic perception of where they are, but it is real to them. A simple walk on a low beam might be too much, even following a line on the ground is nearly an impossible task because all the necessary information from the sensory teams are being processed incorrectly, incompatibility. They can be easily frustrated to try these types of activities, even anxious for physical education or extra circular activities. They are just getting the wrong information and a heightened sense of movement is uncomfortable to function with.