What is Sensory Integration?

Ayres Sensory Integration ®

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In 1989 Jean Ayres defined Sensory Integration (SI) as follows:

“Sensory Integration is the neurological process that organises sensation from one’s own body and from the environment and makes it possible to use the body effectively within the environment.  The spatial and temporal aspects of inputs from different sensory modalities are interpreted, associated and unified.  Sensory integration is information processing… The brain must select, enhance, inhibit, compare and associate the sensory information in a flexible, constantly changing pattern, in other words the brain must integrate it.”

SI theory is intended to explain mild to moderate difficulties in learning and behaviour.

The integration of sensory information from all of the senses is necessary to support optimal function. The senses include vision, hearing, taste, smell and touch, as well as the sense of movement (vestibular) and body position (proprioception). Ayres specifically emphasised the importance of the touch, movement and body position senses in the sensory integrative process (Ayres, 1972).

Sensory integrative disorders also include postural movement disorders, postural – ocular movement disorders and sensory modulation disorders.




To make a diagnosis of sensory integrative dysfunction, there needs to be evidence of a deficit in processing of vestibular, proprioceptive or tactile sensory inputs.

An occupational therapist trained in ASI® will utilise various standardised and non-standardised assessments to collect information regarding the child’s ability to process sensory information. Currently, the Sensory Integration and Praxis Tests (SIPT) are the international golden standard for testing sensory integrative functions. In addition, other tests, checklists and clinical observations are used in conjunction with collateral information from parents/caregivers and educators to assist in identifying sensory integrative dysfunctions. Based on the assessment information, the occupational therapist will develop a hypothesis regarding the underlying sensory integrative difficulties or dysfunctions that contribute to the child’s problems/challenges in activities of daily life.

Assessment in ASI® is an on-going process. Continuous assessment and observation during therapy as well as continued interaction with parents/caregivers and educators are of the utmost importance to guide intervention towards optimally supporting the child.


What could a SI dysfunction include?

Problems in sensory integration occur when the child’s nervous system is unable to process sensory information from the environment and the body effectively. More specifically, sensory integration problems explain those difficulties related to poor sensory processing and motor incoordination that cannot be attributed to obvious central nervous system (CNS) damage or abnormalities.

Difficulties experienced in Sensory Integration dysfunction may include:
• Clumsy behaviour; child may trip / fall often, bump into things etc…
• Postural control may be poor.
• Sensory defensiveness, i.e. fussy dressers (only cotton, seams turned out), fussy feeders, uneasy on jungle gyms/avoid swings, unsettled in noisy environments (e.g. parties/ shopping malls), etc.
• Sensory dormancy (often resulting in seeking behaviours), i.e. constantly moving, fidgeting, touching, making noises, crashing into things, not hearing when being called (despite normal hearing), incomplete work in class due to “daydreaming”, etc.
• Difficulties co-ordinating the two sides of the body and/or crossing the body midline, as seen when swimming, riding a bicycle, eating with a knife and fork.
• Difficulties planning, sequencing and executing novel (new) movement patterns. Takes longer than average to learn new tasks such as riding a bicycle.
• Speech and language development may be affected.
• Poor self-care.
• Difficulties developing and sustaining relationships and poor social skills.
• Difficulty with focus and attention.

Difficulties in SI dysfunction are classified in two areas:
1. SI dysfunction of reactivity
2. SI dysfunction of perception

It is important to always keep differential diagnoses in mind, i.e. emotional issues, Attention Deficit /Hyperactivity Disorders, Hemispheric dysfunction, Autistic Spectrum Disorder, Cerebral Palsy, Down’s Syndrome, hearing and visual impairments.


What is Sensory Reactivity?

Difficulties with sensory reactivity can present as over- or under-responsivity to sensory input and the modulation of sensory information. A child with a well-modulated nervous system adapts effectively to changes in the environment and is able to maintain a level of arousal and attention appropriate to the task at hand. The child is able to block out irrelevant information, attend to relevant information and respond appropriately and adaptively. This enables the child to engage in a meaningful manner in activities of daily life.

  • A child who is over-responsive to sensations, experiences difficulties with filtering sensory inputs and may experience sensory inputs more intensely than most other children. Over-responsiveness may lead to a fight, flight or freeze response to non-threatening stimuli.
  • A child who is under-responsive to sensations may not respond, or show a less intense response, to normal sensory stimuli. These children may appear to “miss” sensory information from their bodies or the environment.


What is Sensory Perception?

Children who struggle with discriminating the spatial and temporal characteristics of sensory input will have problems with tasks such as knowing how hard to press on their pencil, finding an object in a bag without looking, adapting the body during balance activities or learning the spatial orientation of numbers and letters.


What is postural and ocular control and bilateral integration?

Postural and ocular control and bilateral integration difficulties will be noticeable in the performance of daily tasks.

  • Children may struggle with postural and ocular control, which may present as a slouched posture during table-top activities, problems with making postural adaptations while moving during sporting activities, or struggling to maintain visual contact with a moving object such as an approaching ball.
  • They may also experience challenges with integrating the two sides of the body. This may lead to difficulties with bilateral tasks such as throwing and catching a ball, cutting, dressing and motor sequences like skipping and galloping.


What is Praxis?

Children can experience challenges regarding visual- and visual-motor planning, tactile perception and difficulties with imitating, planning and/or sequencing motor actions.

Challenges may also occur in the planning and coordination of new motor actions (this function is known as “praxis”). Children who struggle with praxis may appear clumsy, and uncoordinated, may be hesitant to engage in new motor activities, or may appear as though they do not know what to do with or how to use objects in the environment.



Evaluation in SI is an on-going process. Continued discussion with caregivers, teachers etc. is vital.

A combination of the following is used to gather data:
• Interviews with parents, caregivers, teachers etc.
• Sensory history questionnaires, standardized questionnaires, i.e. The Sensory Profile by W. Dunn, The Touch Inventory for Pre-schoolers (TIP), Sensory Processing Measure Home (by Parham and Ecker), Sensory Processing Measure School (by Kuhaneck, Henry and Glennon) as well as non-standardized questionnaires, i.e. checklist for tactile defensive behaviour, sensory motor history.
• Observations in natural settings, i.e. home / school / playground.
• Clinical observations and formal observations during standardized testing.
• Formal assessment / Standardized testing, i.e. The Sensory Integration and Praxis Tests (SIPT), Millers Assessment for Pre-schoolers (MAP), the Test of Sensory Function in Infants (TSFI) and DeGangi-Berk Test of Sensory Integration.
• Continued observation during therapy and continued interaction with parents is of the utmost importance.



Spandex suspended from 4 points creates a wider area on which to perform activities, but can be more risky.

Occupational therapists trained in ASI® use purposeful activities, specialized equipment and sound clinical reasoning to create opportunities for enhanced sensory integration in therapy.

Therapeutic activities are designed to provide the child with opportunities to master challenges during participation in activities and meet demands presented by the environment. In doing so, the therapist aims to effect change in the naturally malleable nervous system of the young child towards more effective sensory processing.

Once the child is processing and organising sensory information more effectively, he/she will find it easier to interact positively with his/her peers, play creatively and achieve success in all of his/her occupational performance areas at home and at school.


ASI® intervention can only be provided by occupational therapists with post-graduate training in ASI® and is characterised by certain unique features, namely (Schaaf & Mailloux 2015):

  • Therapy will always take place within the context of play.
  • The therapist will establish a therapeutic alliance with the child and collaborate with the child in activity choices.
  • The therapist will create challenges that are just-right for the child, and always ensure success.
  • The therapist will make use of specialised equipment and always ensure a safe environment within which the child can engage.
  • Activities will be rich in sensory inputs, with a particular emphasis on tactile, vestibular and proprioceptive processing.
  • Depending on the child’s unique sensory integrative difficulties or dysfunctions, activities will challenge modulation of sensory input, the ability to discriminate the spatial and temporal characteristics of sensory input, postural and ocular control, integrating the two sides of the body, planning and coordination of new motor actions (praxis) and organisation of behaviour.
  • Therapy will always include collaboration with parents/caregivers, educators and other multi-disciplinary team members.



Ayres, A.J. 1972. Sensory Integration and Learning Disorders. Los Angeles, CA: Western Psychological Services.

Ayres, A.J. 1989. Sensory Integration and Praxis Tests. Los Angeles, CA: Western Psychological Services.

Parham, L.D., Cohn, E., Spitzer, S., Koomar, J.A., Miller, L.J., Burke, J.P., Brett-Green, B., Mailloux, Z., May-Benson, T., Smith Roley, S., Schaaf, R.C., Schoen, S.A., Summers, C.A. 2007. Fidelity in sensory integration intervention research. American Journal of Occupational Therapy, 61(2), 216-227.

Schaaf, R.C. & Mailloux, Z. 2015. Implementing Ayres Sensory Integration®. 2015. AOTA Press: Bethesda.

Van Jaarsveld, A. 2015. The realities of SI assessment and intervention in 3rd world countries. Presentation at European Sensory Integration Congress, Birmingham, UK.