What is Sensory Processing?
What Is Sensory Processing?
All around us exists a world that’s begging to be explored. We’re blessed to have many senses that make enjoying this world a possibility, although for some people, having these senses can be overwhelming. This can be due to what’s known as sensory processing disorder. What exactly is sensory processing, anyway?
Sensory processing is the ability to to manage sensations such as taste, touch, and sound, in the environment around us, as well as from ourselves and make use of these senses. This processing takes place mostly in the brain.
In this in-depth post, we will explore sensory processing in more detail, including a discussion on senses. We’ll also talk about how sensory processing disorder (SPD) causes one to over-process or under-process their sensory abilities and how this may be treated.
Understanding Sensory Processing: What Is It?
When you were a child in school, you were likely taught that you have five senses. It turns out, it’s more like seven or even eight. These are taste (gustatory), smell (olfactory), touch (tactile), hearing (auditory), seeing (vision), body movement (proprioception) and the balance and relation to gravity (vestibular) sense. Some of these were the ones you learned in your schooling, but what are interoception, vestibular and proprioception?
Allow me to explain more about all your amazing senses.
Taste
When you put food in your mouth and appreciate the amazing flavors it has, that’s taste. Psalm 34:8 talks about taste, proclaiming “Oh, taste and see that the Lord is good! Blessed is the man who takes refuge in him!”
Taste comes from our gustatory system, a type of sensory system that lets us experience flavour when we eat. Taste receptor cells within the taste buds in our mouths have a chemical reaction when we ingest food that generates this sense of taste.
Our taste buds are contained in the papillae, or bumps across the tongue. With thousands of papillae on the average human tongue and taste buds by the hundreds in every papilla, we get a rich depth of flavor with every food we’re fortunate enough to eat.
Smell
Mmm, can you smell that? Thanks to your olfactory system, you can. The chemoreception known as olfaction begins when we smell something, known as an odorant. Olfactory receptors within our nose, specifically the nasal cavity, are bound to the odorant.
Receptor signals go to the olfactory bulb, which then transmits information to the brain. This is where our emotional attachment to smells comes from, as well as how we remember things about certain pleasing odours.
Psalm 115:3-8 says this about the ability to smell. “Our God is in the heavens; he does all that he pleases. Their idols are silver and gold, the work of human hands. They have mouths, but do not speak; eyes, but do not see. They have ears, but do not hear; noses, but do not smell. They have hands, but do not feel; feet, but do not walk; and they do not make a sound in their throat.”
Actually, that’s a good Bible verse for all our senses, really!
Touch
When you pet a cat, touch a rock, or wear a cozy cashmere sweater, those all feel different, yes? That’s due to our somatosensory system, which allows us to have the ability to touch. Within that system are neural pathways and sensory neurons that can discern between textural changes.
Our sensory neurons’ axons interact with receptor cells, among which include nociceptors, chemoreceptors, mechanoreceptors, and thermoreceptors. The latter is especially important, as it tells us when a temperature is too cold or too hot. That’s how you know not to touch a burning hot stove.
The gift of touch is mentioned in 1 John 1:1-4. “That, which was from the beginning, which we have heard, which we have seen with our eyes, which we looked upon and have touched with our hands, concerning the word of life – the life was made manifest, and we have seen it, and testify to it and proclaim to you the eternal life, which was with the Father and was made manifest to us – that which we have seen and heard and proclaim also to you, so that you too may have fellowship with us; and indeed our fellowship is with the Father and his Son Jesus Christ.”
Hearing
The auditory system is responsible for producing our ability to hear. The ear, which is a sensory organ, has both an outer and inner portion. When we hear sound vibrations, these travel from the outer ear to the eardrum. Middle-ear ossicles take what’s a low sound pressure and increase the vibration.
The stapes then move the vibrations to the cochlea through the oval window. Perilymph fluid, which is contained within the inner ear, vibrates and changes the shape of the oval window. It now comes inward while the ear’s round window protrudes.
“He who has planted the ear, does he not hear? He who has formed the eye, does he not see?” is a great Bible verse from Psalm 94:9 that relates to our ability to hear.
Seeing
Our visual perception is an incredible gift. Environmental objects reflect a visible spectrum that produces vision or eyesight. This is part of the visual system.
Here’s a further explanation: light from an outside object goes to the cornea, passing through it. The eye’s lens sends the light to the retina, a membrane that’s sensitive to light.
The retina converts that light to a neuronal signal using retinal photoreceptive cells such as cones and rods. The neural signals get moved to the optic nerve, which can send the signals to the brain. Then, we see.
“But blessed are your eyes, for they see, and your ears, for they hear,” proclaims Matthew 13:16, and we agree. Vision is truly a blessed thing.
Vestibular
The vestibular system is based in the inner ear, just next to the hearing system and is powerful for telling us if we are upright or laying down, if we’re falling over or if we’re going up high in a lift. Every time our head changes position or is stimulated by gravity, the semi-circular canals, or utricle or saccule are stimulated and send impulses around the brain to work with the other senses to make sure we don’t trip over and hurt ourselves, or that we can judge how to walk up and down a curb without falling over.
It also plays a part in self-regulation – the ability to keep calm and collected and have the right state of alertness for the task in hand.
Proprioception
Finally, we have proprioception, another of those senses that might not be as familiar to you. This is similar to the name kinanesthesia and relates to our body and how we move it. Proprioceptors in the joints, tendons, and muscles oversee movement, as it connects with our central nervous system, our vestibular system, and our vision.
Interoception – the potential 8th Sense
Here’s a sense that’s quite interesting and not from one particular sense organ. Interoception refers to our body’s internal state and our sense of such. We can sense this consciously, but more often, it’s unconscious. The immune system, endocrine system, nociceptive system, gastrointestinal system, and cardiorespiratory system all use interoception.
It works this way: neural pathways allow our brain to receive interoceptive signals. These then interpret our internal state, and in particular our feeling of hunger and the need to go to the toilet.
It’s believed a slew of disorders may cause problems with the interpretation of these internal states. These include illness anxiety disorder, somatic symptom disorder, autism spectrum disorder, obsessive-compulsive disorder, post-traumatic stress disorder, bulimia nervosa, anorexia nervosa, and depression.
Now that we have a basic concept of the senses, we can talk about how they apply to sensory processing. This involves the use of all the above senses in a way that’s appropriate to the environment and our bodies. This allows us to best interpret and modify bodily movement and behaviour, if necessary, in that environment.
What Is Sensory Processing Disorder?
Many of us use the above senses every single day without thinking much about our sensory processing. For some children and even adults though, processing their senses is not nearly as easy. They have what’s known as a sensory processing disorder.
This presentation technically includes three different conditions: sensory-based motor disorder, a sensory discrimination disorder and sensory modulation disorder. Here’s a further explanation of all three.
Sensory processing disorder can cause issues with organisation as well as attention span and postural control. Sensory-based motor disorder can impact motor skills due to motor information processing issues. A sensory discrimination difficulty causes a difficulty in exactly what is says –being able to perceive the detail in what we see, hear and feel. With sensory modulation disorder, a person may not respond to almost anything or they can overreact to what’s around them.
The lack of a reaction is known as being hypo-sensitive, hypo-reactive while an overreaction is referred to as hyper-sensitivity or hyper-reactivity. Individuals can show different reactions to each different sense and can also fluctuate in their responses depending on the environment and their own neurological state so it’s a complex process to find the right sensory processing issue that is going on. Here’s a deeper explanation into two types of sensory modulation disorders.
Hyposensitivity
Hyposensitivity does not necessarily cause a lack of interest in the world around the child or adult – but it can. Instead, they may try to overcompensate for not experiencing adequate sensory processing.
These children can’t get enough of jumping up and down, such as on a trampoline outside or even inside on the touch. If you or a spouse or partner tosses your child in the air, they may keep requesting it.
They also love intense and speedy movements, such as at amusement parks or playgrounds. Tight bear hugs are appreciated among them, as these hugs create a sense of deep pressure for the child.
Even though hypersensitivity is often associated with lack of stillness, hyposensitive children may also have a hard time staying still. They’ll fidget and move as much as they can. Some find they’re stronger than they realised. They also don’t mind getting hurt, as it takes a lot for them to experience true pain.
Hyposensitive children tend to have problems with personal space, in that they don’t really understand the need for it. Other children in their age group will keep away when necessary, but the hyposensitive child may not.
These children can be very forceful but not even realise it. They may view dropping their dinner dishes off in the sink as an everyday act, where you noticed they slammed the dishes. It’s common for them to bump or trip over things, making them seem clumsy when it could be their sensory processing disorder.
They’re also extremely touchy, not emotionally, but in the literal sense. If there’s something that can be grabbed, pulled, or touched, the child will touch it. It doesn’t matter how inappropriate this can sometimes be; the hyposensitive child is not phased.
Hypersensitivity
Compare that to hypersensitivity, in which a child (or adult) feels too much of everything. This applies to all the senses we covered above. They just become too much to handle.
Personal space is an issue with hypersensitive children as well, but more due to a lack of bodily understanding, which is part of their proprioceptive tactile functioning. Unlike hyposensitive kids, hypersensitive ones stay away from playgrounds, as the equipment and rides here terrify them if it’s their vestibular sense that’s affected.
They don’t like hugs or cuddles either, nor any touch that’s regarded as a surprise. Their sense of hearing can be acute, to the point where the child says they hear noises you cannot. Expect tactile hypersensitive children to have a hard time getting dressed, as clothing that’s too tight, irritating, or itchy will not be worn.
The child may also complain about powerful noises and overly bright lights, both of which are overwhelming.
Symptoms
The above behaviours would technically be considered symptoms of sensory processing disorder. Others include young babies and toddlers who seem especially difficult to deal with. They may cry more or be harder to put down for a nap. Parents who aren’t experienced with sensory processing disorders might think they just have a troublesome child, when in reality, it’s a lot more than that.
Into childhood, these bouts of crying can morph into full-blown meltdowns at home, at school, and even in public. If a hypersensitive child feels overwhelmed, these meltdowns have a higher likelihood of occurring.
Some children with sensory processing disorders can exhibit violent behaviour, such as hitting and throwing. They may also shout and scream. These behaviours only manifest in certain conditions, such as those that are too much for the child.
If they’re in an environment that suits them, they can be perfectly well-behaved. The moment there’s a bright light or another child who needs personal space though, that’s when trouble starts. This can give some parents the impression that their child has mood swings, maybe even bipolar disorder. Instead, the child’s behaviour is linked to their surroundings.
What Causes Sensory Processing Disorder?
If you believe your child has some form of sensory processing disorder, you may wonder what may have led to this. The hard part is no one is quite sure what causes this disorder. It’s believed that genetics could play a role based on a study involving twins published in 2006.
Beyond that, it’s hard to say. Scientists and medical professionals have been hard at work for a long time trying to pinpoint a cause for sensory processing disorder. Their research has generated some interesting findings at the very least.
In one study, children with sensory processing disorder and children without were both physically tested. The researchers either generated a loud sound or tapped the child on the hand continuously.
Those children without sensory processing disorders eventually adjusted to both the physical sensation and the noise. Each time the children with sensory processing disorders heard the sound or felt the touch, they reacted as if it was the first time, and quite strongly, at that.
It’s also been proven that if a child with sensory processing disorder hears loud noises and sees bright lights at the same time, their brain activity changes. That’s as far as that link seems to go.
What doctors and scientists do seem to know for certain is that children with sensory processing disorder tend to have different white matter microstructures than those with ADHD or autism. This white matter within the central nervous system allows brain regions to communicate. White matter also plays a role in brain function and learning ability.
Further, their sensory gating tends to be less active. Sensory gating is one’s ability to sift through brain stimuli from environmental stimuli, determining what’s important and what can be discarded. This prevents sensory overload, which can happen from processing too much at once. That can be particularly overwhelming for those with hypersensitivity from sensory processing disorder.
How Is Sensory Processing Disorder Diagnosed and Treated?
You may feel your child fits the criteria for a sensory processing disorder, but you want to see a professional for a diagnosis and possible treatment. Here’s an in-depth description of how this part of the process could transpire but each locality will have it’s own areas way of working. Of course, the Sensory Super System is here for you to assess and work with you treating sensory processing issues online and helping you become a sensory super parent.
Diagnosis
Sensory processing disorder is in the Diagnostic Classification of Mental Health and Developmental Disorders of Infancy and Early Childhood despite not being referred to as a medical disorder in the latest editions of the Diagnostic and Statistical Manual of Mental Disorders and the International Statistical Classification of Diseases and Related Health Problems. This is also not included in the United Kingdom’s classification. Regardless of whether an actual diagnosis is forthcoming, the reality of the impact is clearly seen by those who have it and those who live with sensory processing issues.
To get a clearer view of a case of sensory processing disorder, occupational therapists will administer a variety of tests. These include occupational therapy gym free play, expert observational scales, standardised questionnaires, and standardised tests.
The standardised questionnaires include the following:
- Sensory Processing Measure Preschool
- Sensory Processing Measure
- Sensory Profile School Companion
- Adolescent/Adult Sensory Profile
- Infant/Toddler Sensory Profile
- Adult Sensory History
The standardised tests include:
- Test of Sensory Functions in Infants
- DeGangi-Berk Test of Sensory Integration
- Sensory Integration and Praxis Test (SIPT)
There also exist a slew of other diagnostic tests that don’t fit into the above categories. These are:
- Behaviour Rating Inventory of Executive Function or BRIEF
- Bruininks-Oseretsky Test of Motor Proficiency
- Miller Function & Participation Scales
- Beery-Buktenica Developmental Test of Visual-Motor Integration
- Developmental Test of Visual Perception
- Clinical Observations of Motor and Postural Skills or COMPS
As you can see, there are dozens of different testing methods, with the SIPT being the gold standard for certain aspects of sensory processing. No one particular test currently covers all areas of SPD. This can make diagnosis difficult, even with language and speech therapists, physiotherapists, learning specialists, psychologists, and occupational therapists involved with the diagnostic process.
Treatment
Professionals will recommend a treatment, the gold standard being Ayres Sensory Integration otherwise known as ASI. Sensory Integration therapy is about generating sensory reactions from the child that involves all senses, normally carried out by Occupational Therapist (OT’s) and increasing numbers of PT’s and Speech and Language therapists. Their job is to combine both the science and art of therapy to make the sessions the most fun and therefore develop the best neural connections possible to improve skills needed for everyday living.
There are 10 principles that drive Ayres Sensory Integration therapy. Four of these are:
- The just right challenge: A more playful part of the therapy, the child will be challenged in multiple ways and encouraged to overcome these challenges by the occupational therapist.
- The adaptive response: The child, who has assessed the challenge, begins to realise what they must do to successfully surmount the challenge.
- Active engagement: To get the child to even undergo the sensory integration therapy in the first place, there must be a fun element. That’s what the active engagement principle is all about.
- Child-directed: The fourth principle involves using the preferences of the child to introduce future experiences that are therapeutic in nature.
A child with sensory processing issues may also benefit from other aspects of therapy. This maintains the key principles of ASI therapy and complements it. Here are these extra elements:
- Whole child focus: Your child’s occupational therapist will work on elements like the child’s self-esteem, self-regulation, and social participation so they may derive more happiness out of their own lives.
- Parent education: The home environment parents provide for their children with sensory processing issues is a major determinant of whether children thrive, get worse while at home or remain regulated. Parent education is thus included in the occupational therapist’s sessions.
- Test-retest systematic assessments: These evaluations are what determines whether a child is the right candidate for sensory processing occupational therapy in the first place and give the opportunity to re-test at the end of therapy to confirm its effectiveness.
- Developmental approach: With the developmental approach, the occupational therapist compares a child’s true age against their developmental age to see where a gap may be and work on those skills.
- Intensity: The therapy sessions, which may start off light and short, may extend as the child loves the sensory play element and sees their progress and how good they feel after a session, or they may have short intense bursts of therapy and then have top-up sessions as required.
It is absolutely possible for children with sensory processing disorder to grow into healthy functioning adults often greatly helped if their occupational therapist imparts the right skills and coping mechanisms. These children-turned-adults may have certain things they need in their day-to-day life, such as sleeping with a weighted blanket or going to the gym daily, and other techniques that they use to live a sensory healthy life.
The self-awareness that comes with adolescence can make a child realise which behaviours to tone down or stop, especially as they crave the acceptance and friendship of their peers. They also learn what they can accept in terms of sensory experiences and what’s too much, then avoid those situations if possible.
Sensory processing disorder may not have a cure – if indeed it needs a cure or can be classed as a disorder, but children with sensory processing issues can certainly thrive and find a meaningful life and place in society with the right understanding and support.
Conclusion
We have a multitude of senses that make our daily lives possible. Those with sensory processing issues may find these senses overwhelm them or make them feel too little. While understanding the cause of sensory processing disorder and even diagnosing it are not straight forward, occupational therapy is a great option for helping a child have a fulfilling life in adolescence and adulthood.