All of the information about the world comes to us through our sensory systems. We are all aware of the senses involved in taste, smell, touch and sound, however our nervous system also senses touch, movement, force of gravity and the position of our body parts. All of these systems are critical in helping us function in everyday life.
We use sensory processing to respond to our environment. For example, if a building catches on fire, we hear the fire alarms, smell the smoke, feel the heat of the fire and feel frightened which will cause us to run out of the building.
Sensory processing is also used to help us get ready for activities. For example:
- Having a shower first thing in the morning to fully wake up
- Having something to eat when we first get home from work or school to settle down
- Wriggling in our chair to help concentrate on our work
- Going for a run to help us calm down
Sensory processing is an uncontrolled response. We cannot choose to prefer or dislike various sensations. A person’s sensory processing style cannot be changed. We can help people develop strategies for coping with different sensory stimulation but we cannot change their underlying sensory profile.
The Sensory Systems and how they help us
Touch: The Tactile Sense
Tactile sensation makes it possible for us to do a range of activities including:
- finding and recognising an object in the dark
- recognising different textures
- protecting us from pain (eg: differentiating between hot and cold)
- helping us hold a pencil.
We receive tactile input during a range of different activities including bathing (the feel of water and different temperatures), dressing (the feel of different fabrics such as soft and rough fabrics), playing (toys with different textures), at school (feel of the chair, pencil, paper) and eating (feeling of different textured foods on the hands and in the mouth).
Movement: The Vestibular Sense
The sense of movement is controlled by our vestibular system that is in our middle ear. The vestibular system responds to body movement through space and changes in head position. This system is used every time we move our head, change position, when we play on equipment such as swings and trampolines, when we use lifts and elevators and when we take off and set down in aeroplanes.
It has 3 purposes:
- to keep us upright
- to provide a sense of our movements to help us move efficiently
- to detect changes in balance and adjust our body position quickly and automatically when we lose our balance.
Body Position: Proprioception
This is closely related to the vestibular sense, and is known as proprioception. This sense gives us awareness of our body position and how much force we are making with movements. It contributes to motor control and motor planning and allows us to skilfully move our arms and legs without looking at every movement.
What can go wrong?
The sensory systems are very complex, and begin to function very early in life. The senses do work separately, but interact with each other in order to allow a person to make an appropriate response.
With any system things can occasionally get jumbled, and not work in the way that they were originally designed too. These systems can mature at different rates, and one of two things usually happens.
- People become overly sensitive to touch, movement, sights or sounds. This refers to a person becoming overly aroused/excited by a sensation that most other people would tolerate.
- People are under-reactive to sensory stimulation. This refers to a person who is generally unaware or does not react to certain sensory input, and may as a result seek out further sensory stimulation.
As a result of this, their behaviour and responses to different stimulation will be different to what you might expect.
But what does this mean?
People with sensory processing difficulties vary in the extent to which they are affected and the sensory systems that are involved. These difficulties can impact on behaviour during functional, everyday activities. Generally people who are under reactive to sensory stimulation will tend to seek out extra sensory inputand those who are oversensitivewill tend to avoid or be defensive of sensory input. This defensiveness may result in irritability, crying, or withdrawal during these sensory experiences.
Behaviours that may be seen when the Sensory Processing systems are not working properly
The following behaviours may indicate difficulties with sensory processing:
Movement (The Vestibular System)
- Seeking Behaviour: The child may be seen to be rocking their body, wagging head, waving or flicking fingers near their eyes. They might enjoy rough and tumble play more than expected. They might be moving their arms and legs more than usual and have difficulty sitting still
- Defensive/Avoidance Behaviour: The child may be seen to persistently sit on the floor, resist movement, hold onto people and become irritable when their position is changed. They may be physically rough with people and objects and appear destructive with toys and objects.
Body Awareness (Proprioception)
- Seeking Behaviour: The child may roll and engage in movement more than expected, clap hands, jump around to an unusual degree, really enjoy rough and tumble play and pushes through arms (eg: doing wheelbarrows, wanting to push and move heavy objects).
- Under registration (does not recognise sensory input): The child may need to watch their physical movement (eg: cannot do up buttons without watching, has difficulty writing without looking at their grip constantly). The child may have difficulty coordinating their movements, often use a slouched posture and be heavy on their feet (“flopping through feet”).
Touch (The Tactile System)
- Seeking Behaviour: The child may frequently suck and mouth on-food objects, hands and clothes. They may scratch or pinch and seek out different tactile experiences and persists with them for extended periods of time.
- Defensive/Avoidance Behaviour: The child might become irritated by certain clothes or fabrics and avoid certain food, such as mixtures of smooth and lumpy textures. They may dislike being towel dried and having their face washed, as well as resisting cuddling and touch and avoiding getting their hands messy.
A child may experience sensory overload when they are unable to process sensory input effectively or when there is too much input to be processed all at once. Overload behaviours may include:
- Running out of the room
- Placing hands over ears
- Becoming distressed
- Repeated play/actions/talking
General Ideas to Manage Sensory Processing Difficulties
As a parent, carer or teacher, the most important thing you can do is to try to understand how the sensory systems influence your child’s behaviour.
Basic Management Strategies
- Make sure your child has a predictable routine so s/he can anticipate when and what stimulation s/he will face.
- Use visual warning to indicate change in routines or changes between activities.
- Keep an ongoing list of your child’s sensory processing behaviours/emotions/responses. This is important as it helps you to understand what triggers these and what helps calm your child.
- Consider the impact of your child’s response to a sensory stimulation. Is their reaction disturbing their ability to participate in the activity? Does their reaction interfere with the rest of the family/class? Is it really important to change that behaviour or can people around your child learn to accept that behaviour?
What to do if Sensory Overload Occurs
- Remember that your child’s behaviour is not deliberate but communicating sensory distress
- Handle the response calmly and without punishment
- Either remove your child from the stimulus or decrease the amount of stimulation
- Allow your child to withdraw and reduce verbal input to the child where necessary
- Provide deep pressure e.g. firm hug and firm stroking to back, arms and legs.
- Know what activities your child enjoys and make these available during periods of overload (keeping an easily-accessible list of activities can be very useful)