What is Sensory Integration?
Sensory Integration is the “organisation of sensations for use”. Our senses give us information about our body as well as the world around us. Sensory information flows into the brain at every moment, and the brain has to organise them so that we can move, learn and behave appropriately. This process of organisation gives meaning to what we have experienced by sifting through all the incoming information and selecting what to focus on. Adequate sensory integration forms the underlying foundation for academic learning and social behaviour – it is the building blocks for the development of sensory motor, perceptual and cognitive development.
The brain has to locate, sort, and order sensations coming in from the world just like a traffic officer directs moving cars. When sensations flow into the brain in an integrated manner, the brain can use these sensations to guide learning, behaviour and motor skills. When the flow is disorganised…life can be like a rush hour traffic jam.
The Development of Sensory Integration
Sensory integration starts in the womb, where the fetus begins to sense the movement and touch of their mother. After birth, the baby is able to hear, see and smell the world around them.
Further sensory integration occurs as the child learns to crawl, stand and walk. Childhood play leads to more sensory integration. By interacting with many things in the world and adapting their body and brain to physical challenges, the child learns to organise the sensations from their body and gravity, along with the sights and sounds around them. That is why play is so important to children – it forms the foundations for their physical, academic, social and emotional development.
“The sensory integration that occurs when moving, talking and playing is the groundwork for more complex sensory integration that is necessary for reading, writing and good behaviour” (Ayres, 2005).
The 7 Senses
There are five common senses that most people are aware of: touch, taste, hearing, vision and smell. But there are 2 hidden senses that the brain also detects: the body position sense (called proprioception). This is the sensations that come from our muscles and joints that tell us where our body parts are in space, and the direction and force of our movements.
The other sense is the sense of movement and gravity (vestibular) that is detected by the sense organs in the inner ear. The process of sensory integration ‘puts it all together’ by taking information from our eyes, nose, mouth, skin, muscles and joints to form the whole experience.
For example, when we eat an orange, our brain has to integrate information from our eyes so we can see its shape and colour. As we touch the orange, we experience the rough texture on the outside and the moistness inside from the information from our hands and fingers. By integrating the smell and information from our nose, we know that the orange has a citrus odour. All this information blends together to form the whole experience of eating an orange.
What happens when sensory information is NOT integrated?
No one organises sensations perfectly. Some people are better than others at integrating sensory information. People like dancers and gymnasts develop very good integration of the body and gravity sensations so that their movements are smooth and graceful. Other people just have average sensory integration. The problem comes in when poor sensory integration starts to interfere with many things in the child’s life. They aren’t able to cope with the ordinary demands and expectations placed on them at home or at school.
It is important to keep in mind that the founder of sensory integration, Jean Ayres believed that sensory integration dysfunction is not as a result of neurological damage…but rather a problem in the central processing of information within the child’s brain.
What causes poor Sensory Integration?
There is no simple answer to this question. There are many theories and correlations to what causes poor sensory integration, but no clear cause has been found.
Some possible causes are:
- Birth trauma (e.g. lack of oxygen)
- Heavy metals
Sensory Processing Disorder
Children who are unable to process and use the sensory information they receive often have a sensory processing disorder. The dysfunction can occur within a specific sensory system, or within many systems. There are 2 ’types’ of sensory processing disorders: Sensory Modulation Disorders and Sensory Discrimination Disorders. Within each type, there are various other dysfunctions.
Sensory Modulation Disorder
Sensory modulation is the process where the brain takes in information and tells us what we need to attend to, and what we can ignore. When a person is well regulated, they can organise and prioritise incoming sensory information to focus on what is relevant and what is irrelevant.
Imagine if we were aware of all the sensory information coming in from the world at every moment of our day – we wouldn’t be able to allocate attention and maintain an optimal level of arousal. Life would be very overwhelming! Some children have an increased level of arousal and are over-responsive to sensory information. This is called sensory sensitivity and it means that they are attending to all the information in their world, rather than inhibiting the irrelevant details.
Children at the other end of the spectrum have a decreased level of arousal. Their brain is under-responding to sensory information and they need more stimulation in order to register, stay alert and maintain an optimal level of arousal. These children are known as sensory seeking. They are the children that move around a lot, fidget, hum to themselves, seek touch, and ‘crash and bash’. Both these types of sensory modulation disorders can cause the child to have problems with allocating attention appropriately.
Sensory Discrimination Disorder
Sensory discrimination is the ability to interpret and differentiate between spatial and temporal qualities of sensory information. The brain tells us specific and refined information about the sensory input we receive. For example, when searching for car keys in a handbag, the tactile system sends specific information to the brain about what the hands and fingers are feeling. Once the brain recognises and identifies the exact shape and details of the car keys, it will alert the person that they have found their keys.
Children who aren’t able to discriminate touch very well, often struggle with writing because it feels like they are writing with gloves on. The detailed integration of information from your visual, touch, movement and body forms the basis for the development of body scheme, motor planning, bilateral integration and visual perception.
Children with sensory discrimination disorders don’t always have problem with sensory modulation. But these problems often coexist in children with sensory modulation difficulties.
What Behaviours do we see?
Because sensory processing and integration happens in the brain, we can’t measure or watch the process occurring to see if there is a problem. What we do see are the behaviours that result from poor sensory integration.
- Delayed motor milestones (crawling, standing and walking)
- Trouble learning to tie laces or ride a bicycle
- Clumsy or accident prone
- Child doesn’t play as skilfully as others
- Slow processing of visual and auditory information, and following of instructions
- Poor listening skills
- Difficulty with colouring, cutting and completing puzzles
- Angry or anxious in crowds, parties and at school
- Often labelled as the ‘fussy’ child
- Difficulties with reading and writing
- Hyperactivity and distractibility
How can we help?
Sensory integration therapy gives the child opportunities for sensory-rich experiences and adaptive responses that help organise the child’s brain. Occupational therapists who are trained in Sensory Integration Therapy offer the child an environment and activities that are designed to neither be too easy or too difficult – we want a “just right challenge”! When the therapist is doing their job effectively and the child is organising their nervous system, it looks as if the child is merely playing. If you are concerned that your child may have a sensory processing disorder, it is best to speak to their teacher or a paediatrician for guidance as to how to get in touch with an occupational therapist trained in sensory integration.