What is Sensory Integration? Sensory Processing Difficulties Explained

What is sensory integration?

Sensory integration refers to the processing, integration, and organisation of sensory information from the body and the environment.

Simply put, this means how we experience, interpret and react to (or ignore) information coming from our senses. Sensory integration is important in all the things that we need to do on a daily basis, such as getting dressed, eating, moving around, socialising, learning and working.

We have multiple senses that receive information, these include:

Vision
Auditory
Tactile
Gustatory
Olfactory
Proprioception
Vestibular
Interoception

Sensory integration, or sensory processing, is an automatic neurological process that occurs throughout our life. Sensory integration develops naturally during ordinary childhood activities, however, for some people, it does not develop as efficiently as it could and can affect activities of daily living, academic achievement, behaviour or social participation. These challenges are often seen in individuals with sensory processing disorder (SPD) and attention deficit hyperactivity disorder (ADHD).

Sensory processing difficulties can be described as

“A decreased ability to process and integrate sensation [that results] in difficulty producing appropriate actions, which, in turn, may interfere with learning and behaviour” (Bundy and Lane, 2020).

Our understanding of sensory integration was initially developed in the late '60s and '70s by Dr A Jean Ayres, an occupational therapist with advanced training in neuroscience and educational psychology, working in the USA. Ayres defined sensory integration as:

“The neurological process that organizes sensation from one’s own body and from the environment and makes it possible to use the body effectively with the environment.” (1972).

Sensory Integration Therapy is based on the theory she developed, which is now known as Ayres Sensory Integration ® (ASI).

What is the difference between sensory integration and sensory processing?

The terms “sensory integration” and “sensory processing” both refer to the processes in the brain that allow us to take the signals from our senses, make sense of those signals and respond appropriately.

The concept of sensory integration was first developed and described by Dr A Jean Ayres in the 1970s. In 2006, Dr Lucy Miller published a model of “sensory processing disorder” based on Ayres Sensory Integration.

Therapists and authors tend to use a particular term depending on where they trained.

What do sensory integration and sensory processing difficulties look like?

What happens if the signals coming from our senses are too weak? Or too strong? Or if our brain over or under reacts to the signals? Or if the brain can’t make sense of those signals? The individual will experience sensory integration difficulties and this may be evident in their behaviour. Some individuals may experience the sensory inputs as overwhelming and upsetting, leading to ‘sensory overload’. Individuals may be over sensitive to sensory input, under sensitive, or both.

It’s common for all of us to occasionally feel under or over sensitive to sensory inputs; for example, music or bright lights may feel too much if you have a headache; you can feel uncoordinated or find it hard to focus if you are tired. But these feelings are temporary and wouldn't normally affect your day-to-day functioning in the long-term. Sensory integration or sensory processing difficulties are long-term and have a big impact on everyday life and learning. But with professional advice and, if appropriate, therapy, much can be done to support improvements in a person’s daily functioning.

Some individuals may have difficulty processing input from one particular sense (eg, visual processing), whereas other individuals may experience difficulty integrating inputs from more than one sensory system. Note that sensory integration difficulties are different from sensory impairments such as hearing loss, although sometimes the two result in similar behaviours. For example, an individual with perfect hearing can find it difficult to follow conversations if they have difficulties processing the incoming auditory signals.

Have a look at our "Day in the Life of" case studies, which describe how individuals, of varying ages, may experience challenges from sensory integration differences in their daily lives.

What are the different types of sensory integration challenge?

Sensory integration challenges or difficulties can be grouped into two main categories:

1. Sensory Modulation Dysfunction

Sensory modulation refers to the brain's ability to filter out and tune into the sensory information that it needs to make sense of the information required for participation in a task. Effective modulation means that we can ignore sensory input not relevant to the task that we are completing.

2. Dyspraxia

Dyspraxia refers to difficulties with motor planning and execution, which can affect a person's ability to perform coordinated movements.

Some individuals may experience one or both categories of sensory integration differences.

There are also subtypes under each broad category.

Sensory Modulation Dysfunction Subtypes

Over-Responsivity

People with over-responsivity may have heightened reactions to sensory input. They may:

Be sensitive to touch, finding activities like nail cutting, messy play, or hair cutting uncomfortable
React strongly to loud or sudden sounds
Avoid playground equipment like swings and slides because they find them overwhelming
Be very picky about certain foods based on their textures, colours, temperatures, etc.

Under-Responsivity

People with under-responsivity may have a reduced reaction to sensory input. They may:

Appear fearless or not notice when they are in pain
Seek out more sensory input, such as fidgeting, rocking, or running around
Frequently mouth or chew on objects
Show poor attention to their surroundings or the people around them

Dyspraxia Subtypes

Vestibular Bilateral Integration and Sequencing (VBIS)

People with this subtype may experience difficulties in processing vestibular and proprioceptive sensations, and it affects the ability to control body extension, balance, bilateral integration, sequencing of movements and motor planning of movements.

Appear clumsy
Struggle with skilled coordination of actions that require smooth and efficient timing and spatial accuracy, eg running to catch or kick a ball
Have difficulty crossing the midline
Have difficulty with completing multi-step activities
Have difficulty with tasks that involve the integration of vision and movement

Somatodyspraxia

Somatodyspraxia relates to difficulties in coordinating and executing new, rather than habitual, motor tasks. It also involves poor tactile, vestibular and proprioceptive processing. People with somatodyspraxia may:

Appear clumsy
Have difficulty planning and organising the sequences of movements in activities such as cutting with scissors or riding a bicycle
Have difficulty with daily activities such as getting dressed, using a knife and fork
Bump into and/ or trip over things frequently
Taking longer to learn skills such as tying shoelaces, writing or ball skills
Have poor gross motor control when running, climbing, jumping, and going up and down stairs
Have difficulty when transitioning from one activity to another
Have low self-esteem

Therapists qualified in sensory integration use this framework to assess and help children and adults with these sensory processing difficulties. They create individually tailored strategies and activities that can improve how individuals process and respond to sensory information, ultimately enhancing their daily life functioning, social interactions, and academic performance. Therapists will also advise on accommodations that can be made to home, school and work environments.

How common are sensory integration problems?

Because sensory integration difficulties can co-occur with other diagnoses (including autism, ADHD, OCD, genetic syndromes and learning disabilities), as well as with no other diagnosis at all, it’s difficult to put an exact figure on the prevalence.

One 2009 *study, found that 1 in every 6 children has sensory processing issues that make it hard to learn and function in school. Other studies have found that **66% of autistic children (65-90% of autistic children, depending on the research study), and 32% of children with special education needs (who were not autistic) show definite differences in sensory behaviours.

More recently, a 2020 paper*** found that sensory processing difficulties predicted executive and cognitive dysfunctions in inhibitory control, auditory sustained attention, and short-term verbal memory in autistic children within a school context.

*Ben-Sasson A, Carter AS, Briggs-Gowan MJ. Sensory over-responsivity in elementary school: prevalence and social-emotional correlates. J Abnorm Child Psychol. 2009 Jul;37(5):705-16. doi: 10.1007/s10802-008-9295-8. PMID: 19153827; PMCID: PMC5972374.

** Green D, Chandler S, Charman T, Simonoff E, Baird G. Brief Report: DSM-5 Sensory Behaviours in Children With and Without an Autism Spectrum Disorder. J Autism Dev Disord. 2016 Nov;46(11):3597-3606. doi: 10.1007/s10803-016-2881-7. PMID: 27475418.

*** Gemma Pastor-Cerezuela, Maria-Inmaculada Fernández-Andrés, Pilar Sanz-Cervera, Diana Marín-Suelves, The impact of sensory processing on executive and cognitive functions in children with autism spectrum disorder in the school context, Research in Developmental Disabilities, Volume 96, 2020, 103540, ISSN 0891-4222, https://doi.org/10.1016/j.ridd.2019.103540

What is sensory integration therapy?

Sensory integration therapy should only be carried out by a qualified SI practitioner: a qualified occupational therapist, speech and language therapist or physiotherapist who has undertaken additional, rigorous postgraduate training in SI. This training involves developing a detailed understanding of neuroscience and the evidence base underpinning sensory integration and developing expertise in assessing and providing intervention for people with sensory integration problems.

SI therapy (or SI interventions) includes structured exposure to sensory input, movement therapy, balance treatments, and carefully designed and customised physical activities and accommodations (e.g., changes to the environment or routine). An SI Practitioner may work with the client, their family, carers, school, other allied health professionals or employer (as appropriate) to create a ‘sensory diet’ for that specific client. A sensory diet is a recommended suite of activities and accommodations (that can be carried out both in therapy sessions and at home or school) to help give that individual the sensory input they need.

You can search the SI Practitioners' Register for therapists who have gained sensory integration qualifications on SIE’s UK-university-accredited MSc in SI pathway.

For many people, small adjustments to their environment or how they are allowed to move at school or work can make a huge difference in how they manage their day-to-day life. We offer a range of courses for parents, teachers and other professionals to help you understand more about sensory integration difficulties and think about changes you can make to your environment or the way you manage work, play or school that will make these activities more accessible to people with sensory integration difficulties.

Course Categories include Everyday Life Skills, Sensory Informed Practice, Autism and Other Co-Occuring Conditions and many more!

Who can practise sensory integration therapy?

Qualified Occupational Therapists; Speech and Language Therapists; and Physiotherapists are eligible to undertake the whole suite of postgraduate qualifications in SI and achieve SIE’s SI Practitioners and Advanced Practitioner statuses. Find out more about SI practitioner training here.

The evidence base for sensory integration

Sensory Integration Recognised as Evidence-Based Practice by US Child Development Research Body

The US-based Frank Porter Graham Child Development Institute, who lead the National Clearinghouse on Autism Evidence and Practice, have published an updated systematic review of literature related to interventions for individuals with autism spectrum disorder (ASD). The 'Evidence-Based Practices for Children, Youth, and Young Adults with Autism Spectrum Disorder' report now recognises sensory integration therapy, specifically Ayres Sensory Integration, as evidence-based practice.

There are several research studies that provide evidence that clinic-based sensory interventions, in particular Ayres Sensory Integration Therapy, may help families achieve their individual goals for their child. Here is a selection of evidence relevant to different settings and looking at populations across the lifespan:

Babies, Children and Young People (Developmental Disorders, Trauma and General)

Autism

Mental Health

If you are a researcher, click here to find out about our research support services and grant awards.

Jean Ayres: the founder of SI theory and practice

Dr A Jean Ayres, the founder of sensory integration theory and therapy: occupational therapist, educational psychologist, neuroscientist, lecturer, widely-published researcher, author and practitioner. As a mentor to hundreds of therapists all over the world, Ayres made life better, not just for the children she personally treated, but for thousands of others.⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀

Ayres was interested in explaining how difficulties with receiving and processing sensory information from one’s body and environment could relate to difficulties at school or using one’s body to engage in everyday life. Ayres developed a theory about what happens when sensory integration does not develop well, she developed a way of assessing these difficulties and a way of treating them. She carried out research to further develop and understand sensory integration and she treated many children with sensory integration difficulties. Since then a number of occupational therapists have continued her work. With new brain imaging techniques, much of what Ayres postulated has been supported.

Dr A Jean Ayres, 1972, photo credit: by family member (personal photo) GFDL, via Wikimedia Commons. ⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀

Ayres received numerous honors from the American Occupational Therapy Association (AOTA)--including the Eleanor Clarke Slagle Lectureship, the Award of Merit, and a charter membership in the AOTA Academy of Research—and was named in the Roster of Fellows. This challenging, compassionate, courageous woman dedicated her life to the promotion of science-driven intervention strategies that enabled a better quality of life for people with disabilities and their families. You can find out more about her life, career and legacy here.