These notes have been drawn up for parents or teachers who may wish to understand more about sensory modulation. They are intended to explain the different types of sensory defensiveness, particularly tactile and auditory defensiveness, which are features commonly seen, and to assist parents and teachers in gaining a better understanding of sensory modulation.
Aggression or overreaction in children is sometimes a feature of a condition known as “sensory defensiveness”. The child may have a tendency to react negatively and emotionally (often aggressively) to touch sensations as well as to other sensory input. They perceive touch which most people would regard as inconsequential, as threatening. The reaction may occur only under certain conditions, and might not always occur. Generally, the child’s sensory defensiveness is worse when he is stressed.
Most people only react negatively to touch sensations which are particularly offensive or which are alerting, such as a fly crawling on their arm. The child who is tactile defensive is inclined to over-react to many ordinary touch sensations, and may react in a negative or emotional manner. Certain touch sensations cause major “disruptions” in his nervous system and cause negative emotions and behaviours. Whereas most people are not aware of the tactile sensations from their clothing touching their bodies or from other irrelevant stimuli, the tactile defensive child’s nervous system is not able to filter and exclude unnecessary sensory information, and the child remains aware of such sensations. He is unable to inhibit the perception of irrelevant sensations and cannot prevent his nervous system from responding to them. He is likely to be distractible, as he cannot attend only to the relevant sensory input. His discomfort may also make him want to move around a lot.
What are the typical features of the tactile defensive child?
He might prefer a long sleeved shirt to keep his arms covered, or he may want to keep a sweater on even when he is warm. He may complain that the labels on the back of his shirt are scratchy, or may refuse to wear certain items of clothing as he finds their texture uncomfortable. Some children may refuse to wear shoes, while others will refuse to walk barefoot. He may avoid getting his hands dirty, and may as a result dislike playing with finger paint or mud. Walking barefoot on grass or sand may elicit a negative response. He often reacts rebelliously to having his face or hair washed, may refuse to have the dentist work in his mouth, or may object to having his nails cut.
The tactile defensive child may experience considerable difficulty when faced with a regular classroom setting. There are lots of other children who brush past him, and who inadvertently touch him. Even the threat of impending uncomfortable touch (for example, the thought of having to stand in line while the school is addressed at assemblies) may be disturbing to this child. He finds it difficult to concentrate and to apply himself to the task at hand. He may however find it easier to concentrate and to apply himself when he is alone at home, as he is probably exposed to considerably less sensory input in this setting. At home, his family are more aware of his “idiosyncrasies” and do not put as much pressure on him as his peers and teachers might at school.
He is likely to dislike being close to other people and may avoid crowds. This child is often perceived as being a naughty or badly disciplined. It will however be seen that he displays aggressive behaviour only when provoked by touch situations which he finds threatening, for example, “ring time” in nursery school. A serious emotional problem could however result over a period of time, as this little child tends to be perceived as being the disruptive child. He may then be labelled as naughty, and in turn may begin to behave in a manner which fits his label, and which meets the expectations of others around him!
On the other hand however, he may try rather to avoid threatening touch situations, presenting as a loner who refuses to go to birthday parties, and who does not enjoy boisterous “rough play”.
Certain children present with a sensory hypersensitivity not only with regard to the sensation of touch, but also with regard to other sensory systems. As explained before, the child may be unable to filter sensory input and therefore responds not only to the significant sensory input, but also to the irrelevant input. He may be over sensitive to sounds. This may cause him to talk very loudly and incessantly when he is exposed to a great deal of background noise. In this manner, he attempts to control the amount of noise input which he receives. (If I’m doing all the talking, I can make enough noise to block out all the other noises which offend me). He may even be fearful of certain sounds, for e.g., the sound of power tools or of the vacuum cleaner.
Certain children are also very sensitive to odours in the world around them. They will often embarrassingly remark on offensive smells and will behave in a manner which indicates just how much that particular smell offends them. Similarly, excessive visual input, such as bright lights, or strong fluorescent light overwhelms them. Sometimes, the child who has difficulty modulating visual input may avoid eye contact. He may then rely more on his peripheral vision and may even feel threatened when he is forced to make eye contact.
When one considers just how much unnecessary information this child has to attend to, and is unable to simply switch his attention off to, it makes sense that he should be so restless and should have such difficulty in assuming a calm disposition. A good concentration ability demands such great effort on his part, that it is something which he can only achieve for very short periods of time, if at all. It also explains why it is that he can manage to cope with tasks requiring concentration, when he is alone at home.
The sensorily “dormant” child
Sometimes, a child may appear to be dormant or “switched off” to sensory input. They often appear not to have registered sensory input as they do not show any reaction to the input. Often parents will have the child’s hearing tested as they are certain that he does not hear properly. The results of the hearing test often show normal if not above average hearing ability, with the child responding to all the frequencies appropriately.
Sometimes, the reason for this apparent lack of arousal is in fact that the child is under-aroused, and therefore does not respond to sensory input with an alert and discriminating response.
More often however, the sensory history provided by the child’s parent will show that he is not “switched off to everything”. He may in fact show signs of being overwhelmed by certain types of sensory input. The parents may also recall that when he was younger, he in fact had difficulty in tolerating certain kinds of input. This group of children are seen as being so over-sensitive to certain types of sensory input, that they are unable to tolerate it and they then move into sensory overload , and sensory shutdown.
Such children appear to have a “dulled” sense of touch and often do not pay attention to auditory input. The child who tends to be “tactile dormant” may have a high pain threshold. He tolerates injections, gashes and grazes far more bravely than would be expected, and does not appear to feel the pain as much as his peers do. He may however feel the need to touch objects more than most children and is forever feeling different textures and touching things. He may particularly enjoy stroking soft fluffy toys. This child’s senses appear to be dulled, although you may think that he presents a confusing picture since you will be aware that he is not unintelligent. It is not always easy to identify such as child as having a problem, since his behaviour is not usually disruptive in any way. He simply presents as an uninvolved child who appears “switched off”.
Many children may present with a confusing picture where both elements of defensiveness and dormancy are noted. They may be hypersensitive to touch at times, whilst having a dulled sense of touch at other times. This occurs as the child moves from a situation of being aroused to the point where his system “shutsdown” and he presents a “dormant” picture; to a less aroused situation where he reacts to sensory input in a defensive manner.
These notes present a simplified description of sensory defensiveness and sensory dormancy.
An Occupational Therapist who is qualified in Sensory Integration would be in a position to answer questions on the subject, and would also be able to provide valuable advice on handling such a child with a Sensory Modulation problem both at home and at school. A Sensory Integration therapy programme could assist such a child in overcoming many of the above problems.