Sensory Processing Disorder (SPD) – What Is It?

Aversion to the hairdresser, picky eating habits, constant fidgeting and bumping into things can all be normal toddler and child behaviours.

They can also all be indicators of difficulties with sensory processing, or a condition known as Sensory Processing Disorder (SPD). As well as being a condition in its own right, SPD can be commonly found alongside other disorders such as autism.

A child whose sensory differences impacts their participation in life – or a child who has SPD – can cause frustration to parents, distress to themselves and to other children.

But with understanding and the right help, many of the difficulties and issues can be managed.

Unfortunately, sensory processing is often misunderstood, and children with significant sensory differences or SPD can be labelled difficult. As a result, they can suffer from learning and behavioural challenges.

Sensory processing disorder is a neurological condition that, according to advocacy organisation SPD Australia, affects as many as one in 20 children. A child with sensory processing disorder will react in a unique way to sensory stimuli like sound, movement and touch.

According to Occupational Therapist (OT) Kristen Pringle, there are four main factors to consider when trying to understand differences in sensory processing.

Firstly, there are four basic patterns of how you may predominately experience sensations, as defined by Winnie Dunn (1999):

• Sensation Seeking ” ‘Seekers’
• Low Registration ” ‘Bystanders’
• Sensation Avoiding ” ‘Avoiders’
• Sensory Sensitivity ” ‘Sensors’

Secondly, people have varying capacities for sensation (neurological thresholds – big cup, normal cup, small cup).

Thirdly, people utilise a variety of management strategies for sensation, by self-regulating actively or passively.

Fourthly, children and adults may experience differences in some, most or all of their sensory systems. The 7 main sensory systems being:

• Auditory (hearing): The ability to process the sounds we hear allows us to interact with our environment and interpret things like distances, voices and sounds.
• Tactile (touch): our sense of touch lets us know where our bodies end and when we come into contact with other people and objects.
• Visual (sight): our visual sense helps us learn about objects, people and boundaries and also governs how we respond to light and movement.
• Olfactory (smell): our sense of smell is our detection and perception of chemicals floating in the air.
• Gustatory (taste): this is our sense of taste which provides sensory information to help us decide what is good to eat and what might harm us.
• Vestibular (balance): an internal sense, tells us where our body is in space in relation to gravity and regulates balance and co-ordinates body, head and eye movement. Our receptors are in the inner ear.
• Proprioception (body awareness): an internal sense, tells us where our body parts are in space in relation to each other and about force of movement required. Our receptors are in muscles, tendons and joints.

Children with sensory differences may also have difficulties modulating within or between sensory systems.

As a result of this different manner of processing sensory information, children may be over-reactive to sensation (such as sounds, smells, light, taste or touch) and will become easily be overwhelmed or avoidant. They may be under-reactive to sensation and will actively seek out sensation (such as noise, smells or touch) or be passive. They can fluctuate between being over-reactive and under-reactive, resulting in children spending less time in an optimal range or arousal where they can attend, learn and concentrate.

Big Cups vs Little Cups (Capacities For Sensation)

Kristen Pringle uses the analogy of takeaway coffee cups to describe how sensory capacity works.

A normal cup is a standard size coffee cup, where someone would experience typical sensory processing.

A big cup is an extra-large size, where a person would experience high levels of sensation as only a little.

A small cup is a babycino sized cup, where a person would experience a small amount of sensation as a high amount.

‘Standard Cup’

A child with typical sensory processing will have a normal sized cup for most if not all of their senses, and they will automatically ‘fill’ and ’empty’ their cup efficiently. Without conscious thought, a child with typical sensory processing will effectively notice or ignore, process and respond to sensation so that their cup does not overflow or run empty, resulting in the child interacting with their environment appropriately.

‘Big Cup’

If a child’s profile is as a ‘seeker’ or a ‘bystander’, they will have a ‘big cup’, which means their nervous system will respond slowly to sensation. Their extra-large coffee cup needs a lot of liquid (sensation) before they are aware of or are able to respond to sensation – it’s as if lots of sensory input feels like just a little to this child.

‘Small Cup’

If a child’s profile is as an ‘avoider’ or a ‘sensor’, the child will conversely have a ’small cup’, where their nervous system responds quickly to sensation. This means that it will take very little sensory input to fill or overflow the child’s ‘babychino’ sized cup. Just a little amount of sensation feels like a lot to the child.

Mixed Cups

To make things more complicated, a child experiencing sensory differences will experience different cup sizes for some, most or all of their seven sensory systems – and these cup sizes may also vary from small, to normal, to big between senses.

A child with sensory differences could have a big cup for their visual senses, so they will require a lot of visual information to fill their cup.

Additionally, if the child self-regulates actively, they may seek out lots of visual information to fill their big cup. They may be drawn to bright or flashing lights and objects that actively move.

However, if the child self-regulates passively, they will need assistance to notice visual information in their environment, and may miss significant visual cues due to their big cup.

At the same time, the child with the big cup for vision could have a small cup for auditory information, meaning that only a small amount of sound would fill or overflow their babychino cup.

A child with a small cup for auditory information will detect and notice sound more quickly, so if the child responds actively they may regularly place their hands over their ears to shut out sound, or leave environments that are noisy due to their small auditory cup.

However, if the child self-regulates passively, they may complain about noises that don’t bother others, or may seem agitated and anxious in noisy environments.

Life With Sensory Processing Challenges

Everyday life can be challenging for a child with significant sensory differences or SPD. They may have emotional meltdowns or outbursts more regularly than most, seem to be overwhelmed easily or avoidant, demonstrate ‘unusual’ or ‘strange’ behaviours, be overly active and ‘on the go’, or seem uninterested and unmotivated.

Although children with significant sensory differences or SPD are just responding to their environment, and are trying to self-regulate to meet their sensory needs. This is often misinterpreted as misbehaviour, and can lead to harsh discipline when what is really needed is help and guidance.

Seeking Help

If you think your child might be experiencing sensory differences which is significantly impacting their development, learning, play, engagement or participation in daily life, or if you think they may indeed have SPD, it’s worth seeking professional advice from a qualified and experienced Occupational Therapist.

With the right help and support, you can help your child learn how to cope with their unique view of the world and minimise the difficulties that sensory differences can cause.