Sensory integration is the organization of information taken in from the senses so that the child can use it to learn and interact with the environment. We are all familiar with the sense organs – the eyes, ears, nose and taste buds that enable us to see, hear, smell and taste. However, there are three other sensory systems (i.e. vestibular, proprioceptive and tactile) that are less obvious and play a major role in sensory integration. This first article in a series of three will discuss the how the vestibular system works and how it can be used in therapy for Sensory Integration and children with autism.
You have probably noticed how movement impacts a person’s level of alertness. Parents slowly rock a baby to sleep using linear movement such as side to side, or up and down swaying; a teacher might lead a class in jumping jacks to wake them up. Children usually find rotary movement such as spinning in circles to be fun and exciting. Adults use movement to reach a level of alertness that makes them feel good such as when relaxing on the hammock or running a marathon. However, because brains differ we seek out different types and degrees of vestibular stimulation.
What is the Vestibular System?
You may wonder how the vestibular system works. The vestibular sense organs are located inside the inner ear. They respond to movement as the head changes position (such as when doing a somersault) or the body accelerates or decelerates (such as when on a roller coaster.) This movement information goes to the brain for processing and then generates muscle tone (so that we can maintain an upright posture), reflexes so that we shift our weight when losing balance and coordination of visual sensations and movement (to discriminate what we see). You can understand the relationship between vision and movement when you consider that just watching ocean waves can make you nauseous and that the eyes rapidly move side to side after one spins.
Vestibular stimulation helps the brain to develop. Tiny crystals inside the ears respond to the head moving in different directions as gravity pulls down on them. The fluid inside what is called the semicircular canals (in the inner ears) responds to changes in speed or direction of movement. All of this information tells a child exactly where he is in relation to the ground and how fast he is moving.
Children often seek out vestibular stimulation as they run, jump, swings, ride a bicycle, dance, roll down a hill, not to mention all the sports and rides they love. Children typically develop strength and muscle tone as they move their bodies in response to gravity, building a foundation for developing more complex motor skills such as peddling a bicycle or drawing a picture.
Autism and the Vestibular Sensory System
For Sensory Integration and hildren with autism, vestibular-based disorders causing them to fear or avoid movement, seek out excessive amounts (appearing to be hyperactive) and/or seem clumsy. Occupational therapy treatment and sensory diets rich in vestibular, as well as proprioceptive and tactile stimulation help these children with motor planning and body awareness so that their brains can better organize information, focus and learn. Here are a few examples of sensory rich activities:
- Fast rotary movements on a tire swing
- Scooting down an inclined ramp
- Crashing into a pillow mountain while flying on an inner tube swing
- Jumping on a trampoline or hopping ball
Part II in this series discusses the impact of proprioceptive stimulation on sensory integration.