Originally published on Nov. 6, 2017.


In a previous post, we've talked a little about three of the 7 sensory systems that your child uses to help make sense of their bodies, learn to move and have appropriate emotional responses to their environment.

These posts are focussing on the vestibular, proprioceptive and tactile systems, because they are so fundamental to the function of all the other sensory systems, and all the other learning that your child will do.

Let's talk a little more about the ways in which children can experience their sensory worlds differently.

Your brain is a clever organ, that, beyond just taking information in and then sending instructions out to the body, also regulates the flow of information coming in so that it is not overwhelmed, but also not understimulated. This process is known as modulation.

For example, when you are reading this, you are getting information from your body to let you know whether you are standing or sitting. If your sensory processing is well modulated, you will get 'just enough' information about your position- not so little that you have to keep focussing on where your body is and are unable to read- not so much that you are in constant fear of falling down, and stressed by the small changes in body position that we all make to stay upright.

People with sensory modulation difficulties have difficulty getting a 'just right' amount of information. They may get too much or too little. This is extremely distracting and can be distressing. These sensory processing tendencies can interfere with all the other things they want to do, to the extent that it can interfere with a child's development.

So- is there an easy way to tell if your child is getting enough sensory information? Sadly, it is not that simple.

Children will seek to adapt their own behaviour to their sensory processing tendencies. A useful way of looking at this is Winnie Dunn's 1997 model of sensory processing:

Dunn's Model of Sensory Processing (1997)

If a child has a high neurological threshold, it means that they need lots of sensory input to happen before the message about the sensation gets passed to the brain. They would not notice a sensation very easily. Some children would take a passive response to this- the information is not getting through, and they don't do anything to adapt to this situation. A child would need lots more sensory stimulus than normal to show a response.

Some children who have a high neurological threshold adapt to this need for more sensory information with an active response. They are 'sensory seekers'- moving more, cramming more into their mouths etc.

If a child has a low neurological threshold, then they only need very little sensory information to pass on sensory information to the brain. As a result, these children are likely to be easily overwhelmed. Again, they can have a passive response to this- these children may look like they are not doing much, but in fact they may be completely overloaded and unable to escape.

Active responses to a low sensory threshold would involve behaviours such as trying to avoid or escape sensation (for example, avoiding getting their hands dirty, becoming distressed at having to have socks on).

Passive responses to either under or over-sensitivity can look similar on the surface. Active responses to under or over-sensitivity can look similar. But our approaches to supporting that child will be quite different. In addition, your child might be over-sensitive to some types of sensation, but under-sensitive to others. This is why it is important to get Professional help if you suspect a sensory modulation difficulty.

For a really great video on this, look for 'A Child's View of Sensory Processing' on Youtube.

Occupational Therapists (OT) are traditionally associated with sensory assessment. Not all OTs are trained in sensory assessment, and so it is important to have access to an OT who has the appropriate qualifications. More and more though, other therapies such as Speech and Language Therapy and Physiotherapy are also training in this area, as sensory processing has such a wide impact on all areas of development.

In our next post, we'll be looking in a bit more detail at the tactile system, including the kinds of behaviours that might be suggestive of under- or over- sensitivity in this system.

Posts from Find the Key Speech Therapy are intended for information. They are not intended to, and cannot take the place of advice from an appropriately qualified Speech and Language Therapist who knows you child. Find the Key Speech Therapy does not take responsibility for the use of any advice without appropriate professional guidance.