Understanding Sensory Processing Disorder

Sensory processing describes the way the body receives and interprets incoming stimuli through our senses. Our sensory systems play an important role in our ability to engage in the world around us. Each sensory system has its own unique role and together they inform our brain how to react and interact with our environment. This process helps us to maintain a sense of position, level of alertness in different surroundings and our ability to move.

Some children, young people and adults find the information that they receive through their senses challenging. Things like hearing, touch, vision, taste and smell are our commonly known senses. In addition to these, there are three other less known senses that also play a big part in and how we and our bodies engage and respond to the world around us. These are Proprioception, a sense of body awareness; Vestibular, which involves movement, balance and coordination; and Interoception which helps us understand and feel what’s happening inside our body.

Sensory Processing Disorder (SPD) is a term that describes the challenges children (and adults) have when their brains are not interpreting the sensory messages they receive from their body effectively.  It can affect or interrupt the messages received from any of their senses.  Another term you may hear is sensory integration dysfunction.

Sensory information is any message that we receive from our senses.  This includes the five senses that most of us are familiar with, taste, smell, sight, hearing, and touch.  It addition, we receive information from our proprioceptive and vestibular senses.

In addition to the five senses, occupational therapists are also concerned with proprioception, vestibular sense, and interoception.

• Proprioception - Our proprioceptive sense is extremely important, and often called the hidden sixth sense.  It receives sensory messages from our muscles and joints.  This helps our body to know where it is in space and how our limbs are moving.  It also helps us to know how much force we are using.  Some example activities that give a lot of proprioceptive feedback include, squeezing an orange, pushing a pram/stroller, cycling, rock climbing and lifting weights.
• Vestibular Sense - The vestibular sense is often called the balance sense.  It receives sensory messages from a part of the inner ear, called the vestibule.  The vestibular sense helps with balance and coordination of movement.  It also helps with alertness.  Activities that give a lot of vestibular feedback include swinging, jumping and fairground rides.
• Interoception - a lesser-known sense that helps you understand and feel what's going on inside your body. Kids who struggle with the interoceptive sense may have trouble knowing when they feel hungry, full, hot, cold, or thirsty. Having trouble with this sense can also make self-regulation a challenge.

SPD can affect one sense or multiple senses. Children who have SPD may overreact to sounds, clothing, and food textures. Or they may underreact to sensory input. This causes them to crave more intense thrill-seeking stimuli. Some examples include jumping off tall things or swinging too high on the playground. Also, children with SPD are not always just one or the other. They can be a mixture of oversensitive and under-sensitive.

Below is a video that shows what is like to experience sensory processing disorder through the eyes of a child.

Kids who are sensory avoiding may react to a wide range of triggers. These can include loud sounds, uncomfortable clothing, crowded spaces, or certain food smells or textures, among others. Whatever the trigger, the reaction can sometimes be extreme.

Sensory overload can lead to sensory meltdowns. These are very different from tantrums because they’re out of the child’s control.

Here are some other signs you might see in your child:

• Is easily overwhelmed by people and places
• Seeks out quiet spots in noisy, crowded environments
• Is easily startled by sudden noises
• Is bothered by bright light
• Refuses to wear itchy or otherwise uncomfortable clothing
• Avoids touching people or hugging them
• Has a strong reaction to the texture or smell of certain foods
• Refuses to try new foods and has a very limited diet of preferred foods
• Gets upset about small changes in routine or environment and avoids trying new things

Kids who are undersensitive to sensory input have the opposite situation. They often have a need for movement. And they may seek out input like spicy or sour tastes and physical contact and pressure.

Here are some other signs you might see in your child at different ages:

• Constantly touches objects
• Plays roughly and takes physical risks
• Has a high tolerance for pain
• Often squirms and fidgets
• Is constantly on the move
• Invades other people’s personal space
• Often gets distracted or feels anxious
• Is clumsy and uncoordinated
• Keep in mind that kids aren’t always one or the other. Some kids may be sensory seeking in certain situations and sensory avoiding in others, depending on how that child is coping or self-regulating at the time. That’s why it’s so important to observe your child’s reactions and to try to anticipate what triggers them.

Lucy Jane Miller, PhD, OTR, is the founder and executive director of the nonprofit SPD (Sensory Processing Disorder) Foundation and of STAR (Sensory Therapies And Research Center). https://sensoryhealth.org/

Lucy Miller has defined three parts to SPD

The first component of Sensory Processing Disorder is modulation.  Sensory modulation is the ability to produce a behaviour and/or response that matches the nature and intensity of the sensory input and environment.  This means that the response to the sensory messages is what would be expected; it would match what had occurred.  The responses of children and adults with SPD often do not match the sensory message or environment. There can be challenges with some or all senses.  Sensory issues related to modulation difficulties can include:

• Over-responsivity, or sensitivity to sensory input;
• Under-responsivity or not responding to sensory input;
• Craving or seeking out extra sensory input.

Sensory modulation is also  called sensory reactivity by some therapists.  These therapists will consider hypo and hyper reactivity.  So, a slower (hypo) reaction.  Or, a bigger (hyper) reaction.  Reactivity is being used to bring terminology inline with the 2013 update of the autism diagnostic criteria in a book called the DSM-V.

The second component of SPD is discrimination.  Sensory discrimination is knowing what the sensory input was, where it happened and how intense it was.  So, if you stub your toe your brain should be able to figure out (or discriminate) which toe it was and how hard you banged it.  When you put your hand into your bag to find your keys, your touch sense can identify (or discriminate) the feeling of your phone and wallet from your keys.  When you open a pot of yogurt your proprioceptive system pulls the lid with enough force to open it but hopefully not spill it everywhere!  These are examples of discrimination.

Some therapists will use the term sensory perception when they are talking about sensory discrimination.

The third component of SPD is sensory-based movement.  In this section, Miller (2041) includes praxis and posture.  Praxis is the ability to plan and organise new and novel movements. It is exceptionally important for learning new skills.  People are often more familiar with the term dyspraxia which means difficulty with praxis or planning.  Posture relates to postural control, balance and stability.

Occupational therapists who specialize in SPD can work with individuals to develop a personalized treatment plan that addresses their specific sensory needs. Some ways that occupational therapy can help with SPD include:

1. Sensory Integration Therapy: Sensory integration therapy involves exposing the individual to controlled sensory input, such as touch, sound, and movement, in a structured and supportive environment. This can help the individual learn to process and respond to sensory input more effectively.

2. Adaptive equipment: Occupational therapists can recommend and provide adaptive equipment, such as weighted blankets, compression garments, or fidget toys, to help individuals with SPD manage their sensory needs.

3. Environmental modifications: Occupational therapists can provide recommendations for modifying the individual's environment, such as reducing noise or increasing lighting, to make it more conducive to their sensory needs.

4. Developing coping strategies: Occupational therapists can work with individuals to develop coping strategies for managing sensory overload or anxiety related to sensory input.

Overall, occupational therapy can play a crucial role in helping individuals with SPD to develop the skills and strategies they need to manage their sensory needs and improve their overall quality of life.

Here are some strategies that parents can use to help children with sensory processing challenges:

1. Create a sensory-friendly environment: Try to create a home environment that is calming and supportive of your child's sensory needs. This may include minimizing clutter, reducing noise levels, and providing a designated quiet space where your child can go to relax.

2. Provide opportunities for sensory exploration: Provide your child with opportunities to explore different types of sensory input in a safe and controlled environment. This could include playing with different textures, such as sand or playdough, or engaging in activities that involve movement or deep pressure.

3. Use visual cues: Use visual cues to help your child understand what is expected of them and to help them anticipate transitions. For example, you could use a visual schedule to show your child the sequence of activities for the day or use a timer to help them understand when it is time to transition to a new activity.

4. Encourage self-regulation: Help your child learn to identify when they are feeling overwhelmed or overstimulated and provide them with strategies to self-regulate. This could include deep breathing exercises, using a weighted blanket or vest, or engaging in a calming activity such as reading or drawing.

5. Seek support: Consider seeking the support of an occupational therapist who specializes in sensory processing disorder. They can work with you and your child to develop personalized strategies for managing sensory input and improving overall functioning.

Remember that every child is different and what works for one child may not work for another. Be patient and persistent in finding strategies that work best for your child's individual needs.

Occupational therapy can be very beneficial for individuals with SPD, as it can help them develop the skills and strategies they need to manage their sensory needs and improve their overall quality of life. Strategies for parents can include creating a sensory-friendly environment, providing opportunities for sensory exploration, using visual cues, encouraging self-regulation, and seeking support from an occupational therapist.

In terms of future research, there is still much to learn about SPD, including the underlying causes of the condition, effective treatment strategies, and ways to improve diagnostic accuracy. Further research is also needed to better understand the impact of SPD on individuals across the lifespan and to develop more effective interventions for individuals with complex and co-occurring sensory, motor, and social challenges.