What is Sensory Integration Disorder?

Sensory Integration Disorder is a complex neurological condition that impairs the functional skills of 1 in 20 children. People with Sensory issues/difficulties misinterpret everyday sensory information, such as touch, sound and movement. They may feel overwhelmed by sensory information, may seek out sensory experiences or may avoid certain experiences.


Main Conditions Classifying Sensory Integration Disorder


1.) Sensory Modulation Disorder &

2.) Sensory Processing Disorder (Expressions of Dyspraxia)

Sensory Integration Disorder - Expression of Modulation Dysfunction

Expression of Modulation Dysfunction

People with Sensory Modulation difficulties experience their world as Hypersensitive (over reactive, sensory avoidance), Hyposensitive (under reactive, sensory seeker) and in some cases a mix of both.


They may also present with motor skill problems (Sensory Processing difficulties). They may react with strong emotional behaviours and experience what may be described as ‘melt downs’. In simpler terms, the brain and nervous system must act as a ‘Filter’ – Filtering in and filtering out sensory input from the environment to achieve the optimal level of arousal in order to attend to the task at hand or simply remain in a state of equilibrium.


Sensory Integration Disorder - Modulation DifficultiesThe brain and nervous system receive input from body parts as well as from the outside world. The central nervous system is also a means of transmitting messages throughout the body and functions somewhat like a computer system. The messages that are transmitted, however, affect functions such as muscle movement, coordination, learning, memory, emotion, behaviour and thought. As with a computer, a breakdown or malfunction in one part of the system often affects other functions of the system.


Sensations from hearing, vision, taste, smell, touch, pressure, and movement provide the input to the brain which is organized for movement, cognition and learning. The richness of the sensory environment and the interactive experience of the individual with the environment contribute to optimal development of function.


When there is a Sensory Processing Disorder, it is hypothesized that the brain does not process or organise the flow of sensory impulses in a way that gives the child precise information about themselves and their world.

Sensory Integration (S.I.) is the term used to describe the way in which the brain sorts out and organizes (for our use) the many sensations which we receive.


Dr. Jean Ayres defined sensory integration as, ‘the neurological process that organizes sensations from one’s own body and from the environment and makes it possible to use the body effectively within the environment” (Ayres, p11, 1989).


Sensory Integration is the body’s ability to:
1. Receive or take in sensory stimuli
2. Interpret the stimuli
3. Process the stimuli into a response; and
4. Adaptively respond to the stimuli


The sensory system takes information from the surrounding environment through touch, smell, sound, vision, taste, movement and gravity. It processes or interprets these sensations together to make sense of the environment. The process of sensory integration lays the foundation for efficient operation of the nervous system and other parts of the body that respond to the signals sent by the nervous system. The child then responds to these sensory inputs and makes appropriate responses to perform skills required.


These difficulties put children with Sensory Issues at high risk for many emotional, social, and educational problems, including the inability to make friends or be a part of a group, poor self-concept, academic failure, and being labelled clumsy, uncooperative, belligerent, disruptive, or “out of control.” Anxiety, depression, aggression, or other behavioural problems can follow. Parents may be blamed for their children’s behaviour by people who are unaware of the child’s “hidden difficulties.”

Developmental pyramid showing Sensory Processing/integration as the foundation for The development of more complex skills That underpin cognition and learning.

Click the image below to enlarge.

Sensory Integration Disorder - How does your engine run?
Look at what the behaviour is trying to tell you rather than judging the behaviour itself