Sensory Processing disorder described in a way that is easy to understand

Sensory Processing-refers to Autism, but other children without autism have these issues as well.  You can have Sensory Processing Disorders without being Autistic, have ADD, ADHD, or have Aspergers.  It is a disorder that can stand alone, but is often coupled with Autism, Aspergers, ADD, and ADHD.  Sometimes children thought to have ADD and ADHD really have a Sensory Processing Disorder. Have your child tested for both so that they are not placed on unneeded medications. 

Let's follow a sensory input on it's journey through our body and see what happens.   Remember, most of the time this happens without us being aware of it.

First, the sensory input.   A sense receptor is stimulated.   It then sends this to the brain.

Next, we have processing.   Sensory information is organised, interpreted, prioritised, stored and related to previous experiences.

Finally, we have the response.   A response to the sensory input in generated.   This could be a motor (behaviour?) response, and thought, or even an emotion (and we talked about how children with autism have trouble understanding emotion when we looked at the triad).

So, where does it go wrong?   Usually with the processing, so lets look at that in a little more detail.

When we looked at learning styles, I talked about people with autism sometimes needing longer to process information.   This goes for everything, including sensory information.   So, if I have autism, and I put my hand on a hot cooker, my tactile sense sends an alert to my brain, which then takes say fifteen seconds to process the information...Ouch!

We also need to look at prioritising.   When you're watching the TV, your brain automatically "tunes out" all irrelevant information, such as the fridge humming, clock ticking and so on, and allows you to focus on the sound and vision from the TV.   This is the 'ability to screen input' in the pyramid I said I'd come back to.   Your brain can filter out what you don't need.   Now, say someone drops a saucepan in the kitchen, your brain suddenly switches your attention to that noise, so that you can consciously decide whether you need to respond.   Now, although the TV is still on, the volume just as loud, for a short while you're not aware of it.   Your brain has prioritised the saucepan over the TV.

We're back to ancestor Ugg twenty thousand years ago.   This time he's sat round the fire, listening to someone telling a story.   His 'filter' has tuned out the crackling of the fire, the sound of the crickets in the grass, the feel of his clothing on his skin.   Suddenly, an unexpected noise in the night, it could be the lion!   Instantly he's alert, ready for action, fight or flight.

Many people with autism seem to lack this filter, so their brains can become overloaded with a deluge of sensory input.   If you just pause to think about how much sensory information your brain is filtering out right now, its astounding.   You have seven senses, all dealing with multiple inputs.   The touch of your clothes on your skin, the chair under your bottom, your hand on the computer mouse or keyboard, your feet on the ground, and that's just tactile!   How many sounds are there, smells, how much clutter is around your computer?   Imagine if you couldn't just ignore it.   Would you be able to concentrate to read these words?

You can try a little exercise to see what its like.   Get family members to rub your arms or legs and chat as they do so, how well can you read these words with all that going on?

Going back to processing, lets also think about 'related to previous experiences'.   When we looked at imagination in the triad, we learned this is something that some people with autism have difficulties with.   If that's the case, then surely every input would be like that dropped saucepan, demanding your conscious attention, making you jump, triggering that 'fight or flight' response just in case.

OK, so that's how SI works in us, and already we've seen where some of the issues are for people with autism, and we haven't even got to the senses themselves dysfunctioning yet!   Well, that's where we're going next.

We all need a certain level of sensory stimulation in order to feel 'normal', to feel grounded.   That's why sensory deprivation affects us so much.   When we don't get enough, we consciously or not seek it out.   If you're in a classroom, listening to a teacher, without thinking about it you may chew your pen or fingernails, twiddle your hair or touch your face and lips (all tactile), or maybe you'll swing back on your chair, stimulating your vestibular sense (and maybe a bit of proprioception).

If you're at home, doing the ironing, you may pop the radio or TV on for a bit of background noise, or hum a little song to yourself.   Too little stimulation and your brain is 'starved'.

Of course, too much stimulation and your brain becomes overloaded, if you have teenagers in the house you'll know what that's like!   Three different stereos playing loudly, the TV blaring, loud voices talking excitedly, this is when you'll take yourself off for a bit of 'peace and quiet' or shout "turn that racket off, I can't hear myself think!", maybe along with an appropriate expletive.

There are other factors that affect our ability to cope with sensory stimulation too, like tiredness or illness.   If you're well rested, you'll probably cope better with the noise children make than if you are tired.

So, basic equation, too little stimulation of a sense, we seek more out.   Too much stimulation of a sense, we try to reduce the input.

Now, for people with autism, their senses can be over sensitive (hyper), or under sensitive (hypo).

• If a sense is over sensitive, their tolerance for sensory input through that particular sense will be greatly reduced.   Normal sensory information will 'overload' them.   They will try and reduce the input.
• If a sense is under sensitive, their brain will be 'starved' of sensory information, they will seek out stimulation of that sense.   They have to do this, in order to 'feel normal'.   The same as we do.   But without the understanding of social rules that we have.