Sensory characteristics
For young people with ASD, the information relayed by the senses and its interpretation is atypical and depends on the individual. The young person may be hypersensitive (over-sensitive) or hyposensitive (under-sensitive) to various sensations, such as light, touch, colours and sounds. For example, background sounds in the environment that rarely bother other people may sound loud and disturbing. The sensory input from the environment can cause anxiety and even feel like physical pain.
The most recognizable sensitivities are related to sight and hearing. Hyper- and hyposensitivities can occur in the same sensory modalities and they can vary greatly at different times in life. They can every vary on a daily basis. Sensory characteristics are often heightened by feelings of tiredness or stress.
“The buzz of an electrical appliance and the light of a fluorescent lamp in the ceiling make it harder for me to concentrate.”
The sensory table shows the special characteristics relating to senses, the hyper- and hyposensitivities.
| SENSORY CHARACTERISTICS | HYPERSENSITIVITY | HYPOSENSITIVITY |
| SIGHT | Avoids bright, flashing lights. Too many colours or bright colours and clutter cause anxiety. Objects moving towards the person may cause fear. | Seeks strong visual sensations. |
| HEARING | Certain audio frequencies can feel unpleasant; sounds of machines and lights, sounds produced by people, unexpected loud noises, multiple simultaneous sounds. | Hearing abnormalities and impairments are possible. Ignores certain sounds. Enjoys noisy places. Enjoys the sound of doors and objects banging or breaking. |
| TASTE | Avoids sour or strange flavours and strong spices. (The structure, colour and smell of food also matters.) | Seeks strong taste experiences (such as strong spices). |
| SMELL | Avoids strong smells and fragrances (people, foods, animals, nature). | Prefers strong smells and fragrances (including unpleasant smells). |
| TOUCH Superficial sensation and deep sensation | Sensitivity to pain. An ordinary touch, certain materials, the seams and washing labels of clothes and socks can feel unpleasant; as can showering and brushing their hair. | Difficulty recognizing pain. Seeks deep sensations in particular. |
| SENSE OF MOVEMENT AND BALANCE | Motor clumsiness. Avoids high places and uneven terrain. Escalators and lifts may feel scary. | Seeks movement input, such as swaying or rocking back and forth. |
Puberty and the senses
Puberty often places greater demands on the senses of young people with ASD. Physical changes in your body can make your body feel strange. The sensory input caused by puberty increases your stress levels, which in turn increases the sensory load. That is why challenging behaviour often becomes more common in puberty.
Taking care of personal hygiene can be difficult for some of the young people with ASD. The young person may not understand the importance of taking care of personal hygiene for the sake of social acceptance, or their sensory characteristics may affect how they take care of personal hygiene. For example, the smell of hygiene products or taking a shower can feel unpleasant and cause an even worse sensory overload. Difficulties related to hygiene skills can also sometimes be explained by difficulties in executive functioning.
Regulating sensory input
Young people with ASD can easily experience sensory overload. Various sounds, lights, smells and crowds of people can trigger sensory overload. Young people can try to reduce the sensory input themselves by turning down some of their senses, for example by using sunglasses or noise cancelling headphones. Withdrawing to a peaceful place and calming down in whatever way works for you (such as breathing and relaxation exercises, various assistive devices for stress management or stimming) can help reduce the input. The purpose of these techniques is to regulate the sensory input and to calm the nervous system, and they should not be limited or forbidden, unless this is absolutely necessary.
What is stimming?
Stimming, or self-stimulation, is a repetitive movement, action, vocal sound or speech that people with ASD use to try to calm themselves down and regulate stress. Stimming typically becomes more common when the person is overactive, nervous, tired, scared or in pain. The purpose of stimming is to calm the nervous system and to bring the wound-up nervous system closer to normal. It can also be used to help relieve tension related to positive things.
It is worth noting that sensory characteristics can also be a strength or a resource that brings you pleasure and helps you relax. That is why you should reserve enough time for gaining and processing sensory experiences.
“I feel deep affection towards certain types of sensory pleasures or experiences. I call these fixations as well, because I seek them out in order to relax.”
