What are sensory processing disorders?
Sensory processing (sometimes called "sensory integration" or SI) is a term that refers to the way the nervous system receives messages from the seven senses (hearing, sight, touch, smell, taste, vestibular & proprioception) and turns them into appropriate motor and behavioral responses.
Whether you are biting into a sandwich, listening to a conversation, riding a bicycle, or reading a book, your successful completion of the activity requires you to process all of the information your body receives, otherwise known as "sensory integration."
Sensory Processing Disorder (SPD, formerly known as "sensory integration dysfunction") has been likened to a "traffic jam" that prevents certain parts of the brain from receiving the information needed to interpret sensory information correctly.
A person with SPD finds it difficult to process and act upon information received through the senses, which creates challenges in performing countless everyday tasks as the sensory signals don't get organized into appropriate responses. Dyspraxia and Auditory Processing Disorder are two of the more commonly known variants of Sensory Processing Disorder.
SPD is not...
Sensory Processing Disorder is not ADD or ADHD, although it is often misdiagnosed as such. Also, it is not a form of autism or Asperger’s, though sensory processing problems often accompany those spectrum conditions. SPD is not a “learning disability” as such, but it may lead to learning and emotional problems.
Type I: Sensory Modulation Disorder (SMD)
Children with SMD can be over-responsive to some of their senses and under-responsive to others.
When the brain over-responds to the messages it receives it is difficult to know which ones to focus on and deal with because they all seem important.
It’s like having your email inbox full with messages all marked “urgent”. The brain simply feels overloaded.
This may lead to:
- Avoidance behaviours
- Aggitation, and
- Distracted behaviours
When this happens children may deliberately seek stimulus - they are busy, full of excitement and seem to have no fear. They are looking for every opportunity to stimulate their senses.Under-responsiveness.
When the brain under-responds to the messages sent to it, it thinks the messages are insignificant and pays no attention. It takes a constant build-up of stimulus before the brain notices and responds.
Alternatively, a child may be slow to respond and thought of as lazy and lethargic, when the real problem is the world doesn’t engage that child.
Type II: Sensory Based Motor Disorder
People with Sensory Based Motor Disorders (SBMD) have difficulty navigating this world – their bodies simply don't do what their brains tell them to do.
There are two types of SBMD:
- Dyspraxia, which involves poor motor coordination, timing, planning, organizing and sequencing, and
- Postural Disorder, which negatively impacts muscle tone, balance, and the ability to operate muscles.
People with dyspraxia may have difficulties with one or more of the following:
- Gross motor skills - this means problems with the ability to carry out movements that involve the large muscles of the body or groups of muscles. Examples of gross motor skills include walking, jumping, running and throwing.
- Fine motor skills - this means problems with performing tasks that are carried out by the smaller muscles of the body, including the muscles of the hands, feet and head or face (including the tongue and the lips). They are more difficult and delicate movements. Examples include writing, drawing, painting, doing a jigsaw puzzle, pronouncing words and whistling.
- Coordination skills – such as poor hand-eye coordination.
- Speech and language problems.
- There may be difficulty in picking up non-verbal signals which can cause social difficulties.
- Learning, thought and memory.
People with postural disorder may have difficulties with:
- Poor core strength which makes movement difficult (e.g. running, skipping, jumping, hopping).
- Poor balance.
- Bilateral coordination – they have difficulty using both sides of the body simultaneously (e.g. catching a ball, rotating trunk to cross the midline of the body to ride a bike).
- Occular-motor abilities. (e.g. following a moving object with their eyes, using peripheral vision and being aware of what happens around them).
- Endurance – they tire quickly.
- Body awareness.