Sensory Series: Introduction to Sensory Processing

Introduction to Sensory Processing


With a few buffer communication posts, I decided it was time to get started on the Sensory Series, after which I hope to eventually introduce an “Approaches to Autism” series. Anyway, this is the introductory post, I will endeavor to post the Sensory Series every Thursday. I hope you enjoy it.

Under section B, point number 4 of the diagnostic criteria for Autistic Spectrum Disorders in the DSMV is an aspect of autism that has finally started to be recognised:

4.       Hyper- or hyporeactivity to sensory input or unusual interests in sensory aspects of the environment (e.g., apparent indifference to pain/temperature, adverse response to specific sounds or textures, excessive smelling or touching of objects, visual fascination with lights or movement).

Even amongst the writings of Hans Asperger can we see reference to different reactions to sensory input, but it took until 2013 for it to enter the diagnostic criteria. For those who do not experience these differences in sensory processing, it can be difficult to believe or understand.

The Senses

Not that long ago, people only really knew about the five main senses, but in recent years with increased research we have begun to give a name to more and more of our senses, and started to look at how these senses are effected in autistic people or people with Sensory Processing Disorder (SPD).

The sense that I have read about (and this is unlikely to be a comprehensive list of all the named senses) are:

  1. Visual – Sight
  2. Auditory – Sound
  3. Tactile – Touch
  4. Olfactory – Smell
  5. Gustatory – Taste
  6. Vestibular – Sense of Balance
  7. Proprioception – Sense of where one’s body and limbs are in space
  8. Nociciption – Sense of pain
  9. Chronoception – Sense of time
  10. Thermoception – Sense of temperature difference
  11. Interoception – Senses stimulated from inside the body

Each one of these can be affected in autistic people or those with SPD. People can be hyperacute (take in too much of the stimuli) or hypoacute (don’t take in enough of the stimuli), and each of the above named senses can be affected.


Alone or as part of something else?

Sensory issues are not something solely linked to autism, but many autistic people (some estimates are as high as 90%+) have difficulties with sensory processing.

It can also be a diagnosis in it’s own right or comorbid with other disorders, such as Obsessive Compulsive Disorders (OCD), Attention Deficit Hyperactivity Disorder (ADHD), and Schizophrenia.

Whilst differences in sensory perception are becoming slowly more accepted when comorbid with autism and ADHD, as a diagnosis in it’s own right there’s still a lot of controversy surrounding it. It is not contained with the DSMV or the ICD-10, and there are two main research papers written on it that are referenced over and again with very different rates:

One study (Ahn, Miller, Milberger, McIntosh, 2004) shows that at least 1 in 20 children’s daily life is affected by SPD. Another research study by the Sensory Processing Disorder Scientific Work Group (Ben-Sasson, Carter, Briggs-Gowen, 2009) suggests that 1 in every 6 children experiences sensory symptoms that may be significant enough to affect aspects of everyday life functions.

Still, it took this long for sensory issues to be fully recognised in autism, so I have no doubt that in another five or ten years we will know more about SPD as a diagnosis in it’s own right. Certainly people diagnosed with SPD can tell you that what they experience is real, whether the DSM or ICD recognise it or not.


So what does this mean for a person?

The impact sensory processing has on a person’s day-to-day life will depend firstly on which of their senses are hyper/hyposensitive, and to what degree they are hyper/hyposensitive. I will discuss each of the senses in more detail later on in the series but to sum it up, it could cause a relatively minor interference to everyday activity or it could cause an enormous interference.

It’s difficult to provide any sort of comprehensive list of symptoms to look out for without flooding this page with a list, especially just considering the symptoms that could be representative of disruptions to the eleven senses I listed above, let alone any others I haven’t learnt about yet. So what I will do is provide a link to the Sensory Processing Disorder Foundation who have a symptoms list as well as a lot of other useful information.

A professor I once listened to explained sensory processing disorders as the brain not knowing what sensory input to attend to. When someone who experiences sensory input without disruption sits in a room their brain will only attend to what it thinks is important. For someone who is hypersensitive to stimuli, their brain doesn’t filter out enough information and so they taken in more stimuli. For someone who is hyposensitive, their brain filters out and doesn’t attend to too much information, so takes in too little stimuli. What’s the important information? The person talking? The coffee machine running? The feel of your jeans on your knees? That strange ache in your stomach? The flickering lights in the building across the street? The tuna sandwich that’s been sat out in the sun all day? Someone might attend to all of this, none of this, or some cross-section in between, as well as a vast amount of other stimuli.

Help for sensory issues ranges widely from Occupational Therapy, through Sensory Integration, through to providing resources such as ear defenders or weighted vests to help the individual manage their sensory processing. Different methods will be discussed more indepth in future posts.

I hope this introduction was interesting and useful, if you have anything to add, leave a comment.

Links and References

SPD Foundation

Ahn, Miller, Milberger, McIntosh (2004) Prevalence of Parents’ Perceptions of Sensory Processing Disorders Among Kindergarten Children

Ben-Sasson, Carter, Briggs-Gowen (2009) Sensory Over-Responsivity in Elementary School: Prevalence and Social-Emotional Correlates.

Disclaimer: The opinions and information provided in this post are my own, and based on personal, educational, and work-based experience. They do not reflect the opinions of any of the authors of the content referenced in this post. I am not affiliated or supported by any organisation, and this is meant to be an educational series of posts. The information posted here is not a substitute for advice and information provided by your own GP, speech and language therapist, occupational therapist or other professional in the field of autism, and should not be taken as such.


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