A Parent’s Explanation of Sensory Processing Disorder (SPD)

By Stephanie Hutchins

Sensory processing what??  If you are like me, you had not heard of Sensory Processing Disorder (also known as Sensory Integration Disorder) before your child, friend, or relative was diagnosed.  I have done some digging and researching of my own, trying to grasp the concepts related with SPD. There have been many times when I have been overwhelmed in my search for understanding and answers.  So, my desire is to try and explain SPD in a way that is easier for me to understand and, hopefully, it may help someone else who is having a hard time understanding it, too.

Dr. A. Jean Ayres developed the theory of SPD in the 1960s.  I will be forever grateful to her for spending the time and having the courage to help kids with sensory processing issues.  The information related to SPD has been out there for over forty years but, I’m finding, most people don’t know much if anything about it.  Well, here we go…

First, let’s discuss the body’s senses.  We all learned about the five senses when we were in school, right?  Taste, touch, hearing, sight, and smell are known as the body’s external senses.  Evidently there are three more internal senses in our bodies:  the vestibular sense, interoception, and proprioception.  Let me explain these three senses and provide examples of what they do.

The vestibular sense helps us to know where our body is in relation to the earth’s surface.  This sense involves the inner ear and affects balance and movement, tells me if I’m moving or if something is moving towards me, and it tells me where I am in comparison to people and objects around me.  I’m moving forward and traveling upward on this escalator.  I’m standing still since the line of people in front of me is not moving.  The basketball bounced off the backboard and is flying towards my head.  I’m running east along this track at a pretty fast clip.

Interoception involves the sensations we get from our internal organs.  My stomach is rumbling and telling me that I’m hungry.  I feel the need to pee or have a bowel movement.

Proprioception tells us what position we are in and how our body parts are moving.  I’m sitting down with my legs crossed at the ankles, arms lying on the armrests of my chair, hands dangling.  I’ll hit the tennis ball if I swing my tennis racket at this angle.  I can dodge the bicycle and jump over the water hose in order to catch the football.  I’m going to use just a little bit of pressure in my fingers to crack open this egg.

All sensory messages travel to our central nervous system, which sends those messages to our brain for interpretation.  We smell smoke; our brain realizes something is burning.  We touch a hot pan and our brain warns us against the pain of a burn.  We see a car running a stop sign and we know not to drive forward just yet.  A piece of ham smells odd and tastes bitter so our brain tells us it might be spoiled.

When sensory processing works right, we get all of these sensory messages through our nervous system and our brain reacts without us having to think about it or having to put forth a conscious effort.  We don’t think about the examples I mentioned in the above paragraphs.  We don’t realize the feeling of our clothes constantly touching our skin, the sound of the air conditioning running in the background, or notice the texture of the carpet touching our bare feet.  Our brain and nervous system takes in all of this information, filters out the important items we need to act on, and takes the rest of the sensory information in stride.  We don’t have to put forth extra effort to process all of this.

Someone with Sensory Processing Disorder has a nervous system that speaks sensory information fluently while the brain only catches every other word, so to speak.  The brain has trouble understanding the information it is receiving from the central nervous system, cannot organize that information well, and definitely has a hard time using that information.

A person with SPD can be over-sensitive to sensory information they receive and a little bit of sensory input will go a long way.  Some people without SPD can be irritated by loud noises, be sickened by the smell of a match igniting, or dislike the texture of bread pudding in their mouth.  People who are over-sensitive to sensory information can be sensitive to these same things except that, instead of these things being just a nuisance, these sensory experiences can be overwhelming, upsetting, and even painful.  A sensory-sensitive person can be overwhelmed by florescent lights, the noise level in a crowded grocery store, the smell of a meal being cooked, the feeling of fabric against their skin, or the texture of mashed potatoes in their mouth.  Any and/or all of these situations can be too much for the nervous system of a person who is over-sensitive to sensory information.

A person with SPD can also be under-sensitive to sensory information they receive and will need more sensory input to try and help their brain and central nervous system stay balanced.  These people are not as sensitive to sensory information and will seek out experiences to provide the extra sensory input their bodies crave.  Some examples of sensory-seeking(looking for more information from the senses) behavior could include spinning, swinging, or jumping a whole lot, rolling on the ground over and over again, climbing and/or jumping off furniture, and running into things.

A person with SPD can also have mixed-reactivity to sensory information.  Sometimes they can be over-sensitive to sensory input and sometimes they can be under-sensitive to it.  They can’t handle listening to rock music one day and will listen to it for an hour the next.  They can’t handle bright colors and patterns at all right now, but later they’ll be staring at books or the TV for half-an-hour.  Cold cereal will be eaten for breakfast one morning, but it will make them gag the next.

As a parent, I can definitely testify to the fact that dealing with a child with SPD can be confusing, frustrating, and overwhelming from one day to the next.  One thing to keep in mind is that the things these kids are doing to avoid and/or seek out sensory information are not bad behavior.  The nervous system is trying to avoid and/or seek out the information it needs to stay balanced and healthy.  The child is not trying to misbehave by climbing on the table for the hundredth time; he actually needs the experience and information provided by climbing.  If you provide acceptable and less dangerous ways for your child to get the same information, then you all can breathe a little easier.  There is help out there for a child with SPD in the form of education, evaluation, and therapy.  A qualified Occupational Therapist, or even a knowledgeable neurologist, can evaluate for SPD and there are different therapies to help.
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