The term “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.
Sensory information is received from our senses, which include:
- Sight (vision)
- Hearing (auditory system)
- Touch (tactile system)
- Taste (gustatory system)
- Smell (olfactory system)
- Proprioception (senses of body awareness and position)
- Vestibular (awareness of movement, balance, and coordination)
- Interoception (our internal sensory system that tells us what is happening inside our body, for example, hunger, needing the toilet, fatigue, emotions, etc)
For most of us, the development of sensory integration occurs when we are young as part of our normal development and in the things we do such as rolling, crawling, walking and in play; for others, sensory integration is less well developed.
Our understanding of sensory integration was initially developed in the late 60s and 70s by Dr A Jean Ayres, an occupational therapist and psychologist with an understanding of neuroscience, working in the USA. Ayres defined sensory integration as:
“The neurological process that organises sensation from one’s own body and from the environment and makes it possible to use the body effectively with the environment.” (1972)
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 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.
Four categories of sensory integration difficulties have been identified (Parham and Mailloux (2015):
Sensory modulation problems
Problems with sensory modulation occur when our brain either over responds to, or under responds to sensory information. For example, if someone over responds to touch they may be very aware of the label in the back of their clothes. If someone is under-responsive to touch they may not notice someone tapping them on the shoulder.
It has been found that people can be over responsive or under responsive in all the different senses, they can be over responsive in one sense and under responsive in another. For some people they can be over responsive and under responsive within the same sense. Responsiveness can be dependent on a situation, for example a stressful situation can make us more and sometimes less aware of sensation.
Sensory discrimination and perceptual problems
This is when the brain has difficulties with making sense of the sensory information it receives. If these problems are with touch sensory information, an individual can seem clumsy or use too much or too little force when doing things. A person with visual perceptual problems may have difficulties with finding objects in cluttered environments or finding a word on a page.
Vestibular bilateral functional problems
These problems are a result of problems with our vestibular sense and can result in poor balance and difficulties with coordinating two sides of the body. Balance and coordination problems could be a result of a range of different problems: a qualified SI practitioner will be able to identify whether the difficulties are a result of problems with the vestibular system.
Praxis is the medical term for how our brain plans for and carries out movements we have not done before. For children this could be learning to jump; for adults it may be learning to drive or use chopsticks.
When sensory information is not properly processed it can make new movements very difficult, because the child does not have the ability to make sense of the different incoming sensory information. So, they struggle to work out where their body is and how much force, speed and direction is needed to do a new movement. We call difficulties with praxis dyspraxia or developmental coordination disorder.
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
Sensory integration therapy should only be carried out by a qualified SI Practitioner: this is 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 the neuroscience and evidence base underpinning sensory integration as well as developing expertise in assessing and providing intervention for people with sensory integration problems.
SI therapy (or SI interventions) include structured exposure to sensory input, movement therapy, balance treatments, carefully designed and customised physical activities and accommodations (eg, 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 to the way they are allowed to move at school or at work can make a huge difference to 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.
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.
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:
- Sensory Integrative Based Occupational Therapy and Functional Outcomes in Young Children With Pervasive Developmental Disorders: A Single Subject Study
- An Intervention for Sensory Difficulties in Children with Autism: A Randomized Trial
- The Effects of Occupational Therapy With Sensory Integration Emphasis on Preschool Age Children With Autism
- Effectiveness of Sensory Integration Interventions in Children With Autism Spectrum Disorders: A Pilot Study
- Systematic Review of Sensory Processing in Preterm Children Reveals Abnormal Sensory Modulation, Somatosensory Processing and Sensory-Based Motor Processing
Evidence-based guidance for those in health, social care or education commissioning services for children with Autistic Spectrum Disorder (ASD) This document presents two case studies.
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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.
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.