Sensory Differences


An autistic person’s sensory experience of the world can have a profound effect on their life. “Parents, care givers, and teachers need to be aware that sensory processing issues can be one of the biggest challenges people on the spectrum experience”. – Nason, B (2014) The Autism Discussion Page: On the Core Challenges of Autism, Jessica Kingsely Publishers, p 129.

A person with autism may experience difficulties interpreting and organising input from what they see, taste, touch, hear and smell. Sensory perceptions can become frightening or even painful and can lead to high anxiety and meltdowns.

“Picture yourself calm and relaxed. Suddenly, a stereo blasts in your ears, and you are punched in the arm…For someone with sensory processing problems, such auditory hypersensitivity might occur in a noisy classroom or hallway. Such touch hypersensitivity might occur with the routine jostling in a school corridor, or the accidental touching by a peer. In other words, everyday life becomes overwhelming.” – Cheng, M (2005) Consider Sensory Processing Disorders in the Explosive Child, Canadian Child and Adolescent Psychiatry Review, 14(2), pp 44–48.

Due to sensory sensitivities, someone with autism might:

  • display unusual sensory seeking behaviour such as sniffing objects or staring intently at moving objects.
  • display unusual sensory avoidance behaviours including evasion of everyday sounds and textures such as hair dryers, clothing tags, vacuum cleaners and sand.
  • display self-stimulatory behaviours e.g. tapping their temples, flapping their hands, bouncing on their toes.
  • be so intensely engaged with a favourite sensation or activity that they may not detect danger.

The seven senses

Alongside the commonly recognised “5 senses” (taste, touch, hearing, sight and smell) a person on the autism spectrum may also over-react or under-react to two additional senses: the vestibular and proprioceptive senses. These senses impact balance, motor skills and body awareness.

Hyper or hypo?

Many people with autism have difficulty processing everyday sensory information. They can be either hyper sensitive (over-reactive) or hypo sensitive (under-reactive) to sensory input, or experience fragmented or distorted perceptions.

A person’s responses to sensory experiences may fluctuate from one day to the next. Some days he or she may seek out certain sensory experiences but on other days he or she may actively avoid that same experience.

“Bright lights, midday sun, reflected lights, strobe lights, flickering lights, fluorescent lights; each seemed to sear my eyes. Together, the sharp sounds and the bright lights were more than enough to overload my senses.” – Liane Holliday Willey

Interventions to help with sensory processing difficulties

Whilst the new DSM-5 includes hyper or hypo sensitivity and unusual sensory interests under the domain ‘Restricted, repetitive patterns of behaviours, interests and activities’, it is important to note there is currently inadequate clinical research into the effectiveness of some specific sensory based therapies. As such, it is important when choosing interventions for sensory sensitivities that these should be assessed carefully and with the overarching needs of the individual in mind.

Modification of the environment is the most accessible intervention for sensory processing difficulties. This involves assessing a child’s sensory processing characteristics by considering their reactions to everyday experiences and modifying aspects of these experiences to counteract their hyper or hypo sensitivities. For example, a child who is overwhelmed by the noises and crowds in the high school hallway between classes may be encouraged to wear a hoodie and listen to music on an MP3 player during the transition between classes to moderate their visual and auditory stimulation. More ideas for environmental modifications for children with sensory processing difficulties at school and at home are available at the Sensory Processing Disorder website.

What is “stimming”?

All people engage in behaviours to help regulate their sensory environment. When these behaviours are overt they become known as “stimming”. The amount and type of stimming an individual on the autism spectrum uses varies a lot from person to person. For example, some individuals with autism may just have mild stimming mannerisms, whereas others spend a lot of time stimming. Most forms of stimming are repetitive or unusual body movement or noises. Stimming can include:

  • hand and finger mannerisms, like finger-flicking and hand-flapping
  • rocking the body back and forth while sitting or standing
  • posturing – holding hands or fingers out at an angle or arching the back while sitting
  • visual stimulation – looking at something sideways, watching an object spin or fluttering fingers or objects near the eyes
  • repetitive behaviour like opening and closing doors or flicking switches
  • chewing or mouthing objects
  • listening to the same song or noise over and over.

“When I’m jumping it’s as if my feelings are going upward to the sky. Really, my urge to be swallowed up by the sky is enough to make my heart quiver. When I’m jumping, I can feel my body parts really well, too–my bounding legs and my clapping hands–and that makes me feel so, so good.” ― Naoki Higashida

If a person with autism is hyper-sensitive to sensory input, stimming can be calming. It may help them to focus, and thus reduce sensory overload. In the case of people who are experiencing hypo-sensitivity, stimming may increase stimulation and help them better focus on their environment or the activity at hand.

“My hearing is like having a sound amplifier set on maximum loudness. My ears are like a microphone that picks up and amplifies sound. I have two choices: 1) turn my ears on and get deluged with sound or 2) shut my ears off […] I can’t modulate incoming auditory stimulation. I discovered that I could shut out painful sounds by engaging in rhythmic stereotypical autistic behaviour.” – Temple Grandin

Further information on stimming can be found via the Raising Children’s Network web article, “Stimming and Autism Spectrum Disorder”. As noted in this web article, stimming isn’t necessarily a bad thing, as long as it doesn’t hurt your child. Some self-injurious stimming – for example, severe hand-biting – may stem from high anxiety. If you are concerned about your child’s stimming behaviours, it is advised to speak to your child’s general practitioner. The GP may refer you to a paediatrician or occupational therapist (OT) for a sensory assessment.