Everyone experiences unpleasant or distracting sensory experiences at some point in their lives. Common ones that can make life intolerable for a while include fingernails scratching against a chalkboard, itchy clothing, bright lights, or very cold foods. Every person has their own list of disliked sensations. No two people's lists will be identical. For example, some people have difficulty sleeping with the television on in the background, while other people find that TV noises help them fall asleep faster. One person may cringe at the sound of squeaky brakes while another might not even notice the sound. Some people enjoy very light touches on their skin while others are ticklish and cannot tolerate such touching.
Extreme sensory issues are very common in autism spectrum disorder. Some children with ASD cannot tolerate sounds or hugs, while another doesn't notice sounds and craves hugs. One child may have an explosive and exaggerated reaction to loud noises, while another may not react at all. Children with sensory issues have difficulty filtering sensory input. Their nervous systems do not know what to block out and what to amplify.
A child with hyperactive sensory systems may avoid engaging in activities that involve motion. They may get motion sickness very easily. They may resist activities like climbing or descending stairs. They may seek assistance with seemingly simple tasks like walking or want to be carried instead of walking.
In contrast, children with hypoactive sensory systems actively seek activities that involve motion. They may enjoy swinging or other activities involving motion. They may not become dizzy after spinning around in circles. They may need to be retrained from excessive motion, rather than needing encouragement to simply engage in motion (as may be the case with children with hyperactive sensory systems).
Sensory integration activities address children's sensory needs by either lessening or amplifying the intensity of various forms of sensory stimulation that children receive. Most sensory integration activities work with children's vestibular, proprioceptive and tactile sensory systems.
The vestibular sensory system helps people to be able to stand upright and to coordinate their movements. It involves sensory input from vision, and from special sensory organs located in the inner ear. Activities that stimulate the vestibular system involve movement. Swinging, jumping and spinning are good examples of such movements. Children with hypoactive sensory systems may engage in such activities as a means of self-stimulation. A therapist looking to help children with hypoactive sensory systems might engage them in learning alternative structured movement exercises which would meet their sensory needs, while helping them stay within socially acceptable bounds.
Children with hyperactive sensory systems have very adverse reactions to many forms of stimulation. They would do better with sensory activities that address their proprioceptive systems. The proprioceptive sensory system helps people to have information concerning their body positioning. Feedback from the proprioceptive system helps people coordinate fine motor activities like coloring within the lines or buttoning a shirt. It is also involved in motor planning, or the ability to coordinate different motor tasks to complete an activity. Activities that stimulate the proprioceptive system include deep pressure, hugging and climbing.
Tactile sensory stimulation involves the sensation of touch and texture. Children with tactile sensory issues may have difficulty tolerating the sensations generated as they dress or groom themselves, or even as they chew food. Therapists may work with tactile-sensitive children to desensitize them to unavoidable textures and touch sensations. This is accomplished gradually over time by teaching affected children to be able to tolerate ever increasing durations of contact with avoided sensations.
Sensory bins are a common tool or prop used during sensory integration activities. Sensory bins are containers that can be filled with various contents (pine nuts, pasta, silk, etc.) to provide a contained experience of an avoided or craved texture. Touch sensitive children with autism spectrum disorder are encouraged to run their hands through these bins to gain controlled access to the stimulation during a desensitization procedure. Alternatively, children who crave particular sensations can use the bins to gain access to their favorite stimulation. In some cases, access to the bins is a reward by itself, which therapists can use to motivate other desired behavior. Sand and water tables or boxes, toys, and/or access to protected play spaces are other means for providing various forms of sensory stimulation to sensitive children.
Sensory integration activities can serve a calming function for children with autism spectrum disorder. In this capacity, they are often used to facilitate communication, attention and motivation. They may be used as rewards for task completion, or they may be provided alongside another task as a calming influence that helps children stay on task. Typically, children are better organized, fluent, and able to attend to tasks when they engage in desired sensory integration tasks. When sensory integration tasks involve two or people, they can be used to help motivate children to socially engage with others.
Part of the reason sensory integration activities are so enjoyable and motivating for children with autism spectrum disorder is because they are closely linked to children's choice of self-stimulatory behaviors. Children engage in self-stimulatory behavior to regulate their sensory inputs, but their spontaneous choices of self-stimulatory activities are sometimes not very socially acceptable. Sensory integration activities can be used to help children satisfy their self-stimulation needs in socially acceptable ways. For example, they might swing on a swing set rather than rocking back-and-forth in their chair. They might hug a pillow or stuffed animal rather than burrowing into couch cushions.