Sensory sensitivity and autism
February 20, 2019
Many people with the Autism Spectrum Disorder (ASD) experience what is called sensory sensitivity. They can be over or under-sensitive to one of the senses; sound, light, taste, body awareness, balance and touch. Their senses – sight, hearing, touch, smell and taste – take in either too much or too little information from the environment around them.
Neurotypical or non-autistic children have sensory difficulties too, which often disappears as they grow older. These sensitivities tend to last longer in autistic children and sometimes decrease over time. Although not all autistic people have sensory difficulties, some might have several. When autistic people are oversensitive or over reactive to sensory experiences, it’s called hypersensitivity. Hypersensitive people might cover their ears when they hear loud noises or eat only foods with a certain texture. When autistic people are under-sensitive or under-reactive to sensory experiences, it’s referred to as hyposensitivity. Hyposensitive people might wear thick clothes on a hot day, or repeatedly rub their arms and legs against things.
Nevertheless, some autistic people can have both over-sensitivities and under-sensitivities in different senses, or even the same sense at different times. For example, they might be oversensitive to some sound frequencies and under-sensitive to others.
When sound is under-sensitive, autistic people might only hear sounds in one ear, the other ear having only partial hearing or none at all. They may not acknowledge particular sounds and might enjoy crowded, noisy places or bang doors and objects. On the other hand, when sound is oversensitive, noise can be magnified, and sounds become distorted and jumbled. They may be able to hear conversations in the distance and may also be unable to cut out sounds – notably background noise, leading to difficulties concentrating.
When some autistic people experience under sensitivity to smell, they may have no sense of smell and fail to notice extreme odours (this can include their own body odour), some may even lick things to get a better sense of what they are. However, when smell is over-sensitive, it can be intense and overpowering. This can cause toileting problems, a dislike for people with distinctive smell; perfumes, shampoos, etc.
When taste is under sensitive for autistic people, they may dislike very spicy foods, eat or mouth non-edible items such as stones, dirt, soil, grass, metal, faeces. This is known as pica. Yet, taste under sensitivity could lead them to find some flavours and food too strong and overpowering because of very sensitive taste buds, has a restricted diet, certain textures cause discomfort and they may only eat smooth foods like fufu or ice-cream. Some autistic people may limit themselves to bland foods or crave very strong-tasting food. As long as someone has some dietary variety, this isn’t necessarily a problem.
When sight is under sensitive, autistic people may find objects appearing quite dark, or lose some of their features. Central vision may appear blur but peripheral vision quite sharp. A central object may be magnified but things on the periphery blur. They may also experience poor depth perception, problems with throwing and catching and clumsiness. On the other hand, when sight is over-sensitive, autistic people experience distorted vision; objects and bright lights can appear to jump around, images may be fragmented, they may squint when out in sunlight, they may find it easier and more pleasurable to focus on a detail rather than the whole object. They may also have difficulty getting to sleep due to sensitivity to light.
Under-sensitivity to touch could lead autistic people to hold others tightly because they need to do so before they feel the sensation of having applied any pressure. They may have a high pain threshold, be unable to feel food in the mouth and may even self-harm. They may enjoy heavy objects (eg. heavy blankets) on top of them. Some may even smear faeces as they enjoy the texture, chew on everything, including clothing and inedible objects. Touch over-sensitivity in autistic people may include touch feeling painful and uncomfortable – some autistic people may not like to be touched and this can affect their relationships with others. They may dislike having anything on hands or feet, difficulties brushing and washing hair or teeth. They may find many food textures uncomfortable and only tolerates certain types of clothing or textures. They may have a strong dislike for labels on the inside of clothes.
Autistic people also face sensory difficulties with their balance. Balance under-sensitivity may include the need to rock, swing or spin to get some sensory input or move in a poorly planned and uncoordinated way. Over-sensitivity to balance may involve difficulties with activities like sport, where we need to control our movements, difficulties stopping quickly or during an activity, car sickness, difficulties with activities where the head is not upright, or feet are off the ground. Some may be very agile.
Body awareness (proprioception)
Our body awareness system tells us where our bodies are in space, and how different body parts are moving. Some autistic people also face sensory difficulties with their body awareness. Under-sensitivity to body awareness may include standing too close to others, because they cannot measure their proximity to other people and judge personal space, finding it difficult to navigate rooms and avoid obstructions. They may also bump into people as they may not be aware of their personal space, they may seem to ‘throw’ themselves across people or stand on people’s toes. Some autistic people may also face body awareness over sensitivity which may include difficulties with fine motor skills, e.g. manipulating small objects like buttons or shoe laces and also moving their whole body to look at something.
Sensory difficulties can affect the whole family as it dictates the places the family visit or the kind of activities, they are involved in.
What you do to support the autistic person with sensory difficulties depends on the type of sensitivity. Some tips will include:
Have a ‘quiet space’ your child can go to when they feel overwhelmed.
Give your child extra time to take in what you’re saying.
Allow your child to play more outside.
Teach your child which objects are hot and cold: you could try labelling objects in your house as ‘hot’ or ‘cold’, using either words or symbols, like fire and ice.
Keep dangerous objects out of reach: keep hot soup away from children
Explain sensitivity to other people so that they too can help in giving your child or family member the right support.
Shut doors and windows to reduce external sounds while at home
Preparing the person by informing him before going to noisy or crowded places
Create a routine around regular washing and using strong-smelling products like African black soap to distract people from inappropriate strong-smelling stimuli (like faeces). Unscented soap and perfume avoidance and making the environment as fragrance-free as possible can help with smell oversensitivity.
With these, you will be on the right track in supporting the autistic person with sensory sensitivity.