Many children with autism spectrum disorders and other developmental disabilities have difficulty with “sensory processing,” which is the way our sensory systems (traditionally, touch, smell, sight, sound, and taste) take in information from the environment and make sense of it, so that we can respond in an appropriate way.
Overview of the Sensory Systems
At every moment, our senses are inundated with new and old information. For those who have sensory systems that are working the way they should, the systems filter out irrelevant information (for example, the sound of the clock ticking, the feel of our shirt on our body, the subtle flickering of the fluorescent lights), and then prioritize the information that is allowed into our conscious awareness.
New sensory input (a doorbell ringing, the feeling of something too hot)—or a change in the intensity of an already existing stimulus (the radio volume turned up, car decelerating to an abrupt stop) —is registered as important because it signals a change in the environment.
Conversely, our brains allow us to get used to or “habituate” to sensory information that remains in a constant state (the hum of the refrigerator, the feeling of our watch on our wrist) so that our attention can be diverted to the processing of more relevant information.
When these sensory inputs and organizing functions are not working the way they should, a person may be said to have a “sensory processing disorder.” Below are additional examples of sensory processing challenges your child might be experiencing.
Under- Responsive and Over-Responsive Sensory Systems
In addition to difficulties filtering out irrelevant stimuli and prioritizing sensory information, there can be significant differences in the way a child perceives specific information in one or more sensory systems.
Maybe your child is one who screams when he is touched gently, who covers his ears at seemingly benign environmental sounds, or who gags on foods that other children tend to love.
Or perhaps your child doesn’t respond being called by name, doesn’t notice that she is slipping out of her chair, or isn’t aware that her clothing is twisted on her body. These behaviors can also be indicators of a sensory processing disorder.
Many sensory processing issues fall into one of two categories: sensory modulation and sensory discrimination.
Sensory modulation is our ability to turn sensory information into behaviors/responses that match the nature and intensity of the stimulus. When this process is disrupted, the result is over-responsivity or under-responsivity. Children who are over-responsive tend to respond more intensely or quickly to a stimulus than would be expected. Examples of under-responders, are children who don’t realize that their shoes are on the wrong feet or don’t hear the teacher saying that it’s time for snack.
Sensory discrimination refers to our ability to detect variability among sensations in one or more sensory systems (for example, discriminating between a pencil and a ruler when reaching into one’s backpack, or being able to tell the difference between something that tastes salty or sweet).
The “Other” Senses
Ineffective processing of sensory information can also have an impact on our motor system, which is our ability to move effectively and safely.
Maybe you have a child who is always “crashing” into other kids, or who can’t figure out how to hop or do a jumping jack, or who can’t walk on a balance beam or go down a flight a stairs with alternating feet. These behaviors likely represent another category called “sensory-based motor disorders."
Sensory-based motor disorders often involve inadequate processing of information from two other sensory systems (our “deep senses”): 1.) our vestibular system (which provides information about our position relative to gravity, balance, and movement) and 2.) our proprioceptive system (information from our muscles and joints). A third sense—our tactile system (sense of touch) —is also critical to our awareness of the body and how it moves.
These three sensory systems—when working properly together—integrate and allow us to move appropriately and effectively. Likewise, information from these systems contributes to our ability to maintain an upright posture against gravity, and to effectively plan movements and sequence actions without over-reliance on our visual system.
The integration from these systems allows us to do tasks such as put a shirt on over our head without falling over, operate the steering wheel in our cars while keeping our eyes on the road, and step onto an escalator without falling down. Other times, we must use our vision to anticipate the demands of a given task (for example, picking up a glass that is full, pulling open a heavy door).
Ineffective processing and integration from our various sensory systems can lead to difficulty in social situations, frequent accidents, and frustration. Children who have difficulty with effective proprioception, for instance, might be too rough with other children, bump into them, appear clumsy, and fall out of a chair in class. Children who have difficulty with tactile processing, might over-respond to “normal” social touch or withdraw from play activities because they don't like the feeling of paint on their hands or the texture of sand.
Understanding your child’s unique sensory profile is important so you can create a personalized “sensory diet” for him or her— a daily schedule of sensory-enriched activities, equipment, and strategies to help your child stay focused and on task throughout the day.
Consultation with an occupational therapist can also be very helpful in understanding your child’s sensory needs and identifying strategies that will allow him or her to be successful at home, in the community, and at school. It is certainly difficult because of the ever-changing overlap of environments, people, and tasks, but with a greater awareness of your child’s sensory challenges and the addition of a sensory diet and sensory strategies, you are increasing the chances that your child will thrive wherever he or she happens to be.
How Does Your Engine Run? A Leader's Guide to the Alert Program for Self-Regulation by Mary Sue Williams and Sherry Shellenberger (1996).
Just Take a Bite: Easy, Effective Answers to Food Aversions and Eating Challenges! by Lori Ernsperger, Tania Stegen-Hanson, and Temple Grandin (2004).
My Book Full of Feelings: How to Control and React to the Size of Your Emotions by Amy V. Jaffe and Luci Gardner (2006).
Raising a Sensory Smart Child: The Definitive Handbook for Helping Your Child with Sensory Processing Issues by Lindsey Biel and Nancy Peske (2007).
Sensational Kids: Hope and Help for Children with Sensory Processing Disorder by Lucy Jane Miller and Doris A. Fuller (2007).
Take Five! Staying Alert at Home and School by Mary Sue Williams and Sherry Shellenberger (2001).
The Incredible 5-Point Scale: Assisting Students with Autism Spectrum Disorders in Understanding Social Interactions and Controlling Their Emotional Responses by Kari Dunn Buron and Mitzi Curtis (2004).
The Out-of-Sync Child: Recognizing and Coping with Sensory Processing Disorder by Carol Stock Kranowitz (2006).
The Out-of-Sync Child Has Fun: Activities for Kids with Sensory Processing Disorders by Carol Stock Kranowitz (2006).