Sensory differences

Processing everyday sensory information can be difficult for autistic people. Any of their senses may be over- or under-sensitive, or both, at different times. These sensory differences can affect how they feel and act, and can have a profound effect on a person’s life. Here we help you to understand autism, the person and how to help.

You can also find out about synaesthesia, therapies and equipment. 

Too much information 

Sometimes an autistic person may behave in a way that you wouldn't immediately link to sensory differences. A person who finds it difficult to process everyday sensory information can experience sensory overload, or information overload. Too much information can cause stress, anxiety, and possibly physical pain. This can result in withdrawal, distressed behaviour or meltdowns.

"If I get sensory overload then I just shut down; you get what's known as fragmentation...it's weird, like being tuned into 40 TV channels." 

- an autistic person

If someone is having a meltdown, or not responding, don’t judge them. There are things that you can do to help. This can make a world of difference to autistic people and their families. Often, small changes to the environment can make a difference. Creating a sensory profile may help you to work out what changes are needed. Three points to remember are: 

1. be aware. Look at the environment to see if it is creating difficulties. Can you change anything?

2. be creative. Think of some positive sensory experiences

3. be prepared. Tell the person about possible sensory stimuli they may experience in different environments. 
   

Sensory differences 

Here we look at some of the effects of hypersensitivity or hyposensitivity to sights, sounds, smells, tastes, touch, balance and body awareness, and ways you could help. 

Sight 

UNDER-SENSITIVE 

• objects appear quite dark, or lose some of their features

• central vision is blurred but peripheral vision quite sharp

• a central object is magnified but things on the periphery are blurred

• poor depth perception, difficulties with throwing and catching, clumsiness.  

OVER-SENSITIVE 

• distorted vision - objects and bright lights can appear to jump around

• images may fragment

• easier and more pleasurable to focus on a detail rather than the whole object

• has difficulty getting to sleep as sensitive to the light.  

You could make changes to the environment, such reducing fluorescent lighting, providing sunglasses, using blackout curtains and/or creating a workstation in the classroom - a space or desk with high walls or divides on both sides to block out visual distractions. 

Sound 

UNDER-SENSITIVE 

• may only hear sounds in one ear, the other ear having only partial hearing or none at all

• may not acknowledge particular sounds

• might enjoy crowded, noisy places or bang doors and objects. 

You could help by using visual supports to back up verbal information, and ensuring that other people are aware of the under-sensitivity so that they can communicate effectively. To meet the person’s individual sensory need, include experiences they enjoy in their daily timetable. 

OVER-SENSITIVE

• noise can be magnified and sounds become distorted and muddled

• may be able to hear conversations in the distance

• inability to cut out sounds – notably background noise - leading to difficulties concentrating. 

"Do you hear noise in your head? It pounds and screeches. Like a train rumbling through your ears." 

- Powell, J., in Gillingham, G. (1995), page 41 

You could help by: 

• shutting doors and windows to reduce external sounds

• preparing the person before going to noisy or crowded places

• providing ear plugs and music to listen to

• creating a screened workstation in the classroom or office, positioning the person away from doors and windows. 
  

Smell 

UNDER-SENSITIVE 

• some people have no sense of smell and fail to notice extreme odours (this can include their own body odour). 

• some people may lick things to get a better sense of what they are. 

You could help by creating a routine around regular washing and using strong-smelling products to distract people from inappropriate strong-smelling stimuli (like faeces). 

OVER-SENSITIVE 

• smells can be intense and overpowering. This can cause toileting problems

• dislikes people with distinctive perfumes, shampoos, etc. 

"Smells like dogs, cats, deodorant and aftershave lotion are so strong to me I can't stand it, and perfume drives me nuts."  

- Gillingham, G. (1995), page 60

You could help by using unscented detergents or shampoos, avoiding wearing perfume, and making the environment as fragrance-free as possible. 

Taste 

UNDER-SENSITIVE

• likes very spicy foods

• eats or mouths non-edible items such as stones, dirt, soil, grass, metal, faeces. This is known as pica. 

• 
  

OVER-SENSITIVE

• finds some flavours and foods too strong and overpowering because of very sensitive taste buds. Has a restricted diet

• certain textures cause discomfort - may only eat smooth foods like mashed potatoes 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. Find out more about over-eating and restricted diets. 

Touch

 

UNDER-SENSITIVE 

• holds others tightly - needs to do so before there is a sensation of having applied any pressure

• has a high pain threshold

• may be unable to feel food in the mouth

• may self-harm

• enjoys heavy objects (eg weighted blankets) on top of them

• smears faeces as enjoys the texture

• chews on everything, including clothing and inedible objects. 
  

You could help by: 

• for smearing, offering alternatives to handle with similar textures, such as jelly, or cornflour and water

• for chewing, offering latex-free tubes, straws or hard sweets (chill in the fridge). 
  

OVER-SENSITIVE 

• touch can be painful and uncomfortable - people may not like to be touched and this can affect their relationships with others

• dislikes having anything on hands or feet

• difficulties brushing and washing hair because head is sensitive

• may find many food textures uncomfortable

• only tolerates certain types of clothing or textures. 

"Every time I am touched it hurts; it feels like fire running through my body."  

- Gillingham, G. (1995), page 3 

You could help by: 

• warning the person if you are about to touch them - always approach them from the front

• remembering that a hug may be painful rather than comforting

• changing the texture of food (eg purée it)

• slowly introducing different textures around the person's mouth, such as a flannel, a toothbrush and some different foods

• gradually introducing different textures to touch, eg have a box of materials available

• allowing a person to complete activities themselves (eg hair brushing and washing) so that they can do what is comfortable for them

• turning clothes inside out so there is no seam, removing any tags or labels

• allowing the person to wear clothes they're comfortable in. 
  

Balance (vestibular)

 

UNDER-SENSITIVE 

• a need to rock, swing or spin to get some sensory input. 

You could encourage activities that help to develop the vestibular system. This could include using rocking horses, swings, roundabouts, seesaws, catching a ball or practising walking smoothly up steps or curbs. 

OVER-SENSITIVE 

• 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. 
  

You could help by breaking down activities into small, more easily manageable steps and using visual cues such as a finish line. 

Body awareness (proprioception)

 

Our body awareness system tells us where our bodies are in space, and how different body parts are moving. 

UNDER-SENSITIVE 

• stands too close to others, because they cannot measure their proximity to other people and judge personal space

• finds it hard to navigate rooms and avoid obstructions

• may bump into people. 
  

You could help by: 

• positioning furniture around the edge of a room to make navigation easier

• using weighted blankets to provide deep pressure

• putting coloured tape on the floor to indicate boundaries

• using the 'arm's-length rule' to judge personal space - this means standing an arm's length away from other people. 
  

OVER-SENSITIVE 

• difficulties with fine motor skills, eg manipulating small objects like buttons or shoe laces

• moves whole body to look at something. 
  

You could help by offering 'fine motor' activities like lacing boards. 

Synaesthesia 

Synaesthesia is a rare condition experienced by some autistic people. An experience goes in through one sensory system and out through another. So a person might hear a sound but experience it as a colour. In other words, they will 'hear' the colour blue. 

References 

Gillingham G. (1995) Autism: handle with care!: understanding and managing behaviour of children and adults with autism.

Future Education Inc.