With taste and touch, we find pronounced likes and dislikes. Many children have an abnormally strong dislike of particular tactile sensations. They cannot tolerate the roughness of new shirts or of mended socks. Washing water can be unpleasant. There is hypersensitivity to noise in particular situations and also hypersensitivity in other situations. Hans Asperger (1944)
Some adults with AS consider their sensory sensitivity to have a greater impact on their daily lives than problems with making friends, managing emotions, and finding appropriate employment.
The most common are very specific sounds, but tactile, light, taste, and texture of food and specific aroma sensitivities can also occur. There can be an under- or over-reaction to pain and discomfort, and the sense of balance, movement perception, and body orientation can be unusual. Everyday sensations are perceived as unbearably intense or apparently not being perceived at all. The person with AS is bewildered as to why other people don’t have the same level of sensitivity.
Parents may report the child notices sounds too faint for others to hear, is overly startled by sudden noises, or perceives sounds of a particular pitch (hand dryers or vacuum cleaners) as unbearable. They cover their ears to block out the sound or are desperate to get away from the specific noise. The child may dislike gentle gestures of affection such as a hug or a kiss, as the sensory (not necessarily the emotional) experience is unpleasant. Bright sunlight can be almost ‘blinding’, specific colours are avoided as being too intense, and the child may notice and become transfixed by visual details, such as dust floating in a shaft of sunlight. Self-imposed diets exclude food of a specific texture, taste, smell, or temperature. Aromas such as perfumes or cleaning products may cause nausea. Problems of balance may cause fear of having their feet leave the ground or hate being held upside down.
In contrast, there can be a lack of sensitivity to some sensory experiences, such as not responding to specific sounds, a failure to express pain when injured, or an apparent lack of need for warm clothing in extremely cold winter. At one moment, they can be hypersensitive and, at another moment hyposensitive. Some sensory experiences evoke intense pleasure, such as the sound and tactile sensation of a washing machine vibrating or the range of colours emitted by street lights.
Sensory Overload
The corridors and halls of almost any mainstream school are a constant tumult of noises echoing, fluorescent lights (a particular source of visual and auditory stress for people on the autistic spectrum), bells ringing, people bumping into one another, the smells of cleaning products, and so on. For anyone with sensory hypersensitivities and processing problems typical of an autistic condition, the result is that they often spend most of their day perilously close to sensory overload.
These intense sensory experiences are described as ‘dynamic sensory surges’ and result in the person with AS being extremely stressed, anxious, and almost ‘shell shocked’ in situations that are not perceived as aversive but enjoyable for other children. The child with sensory sensitivity becomes hypervigilant, tense, and distractible in sensory-stimulating environments such as the classroom, unsure when the next painful sensory experience will occur. The child actively avoids specific situations such as school corridors, playgrounds, busy shopping malls, and supermarkets which are known to be too intense a sensory experience. The fearful anticipation can become so severe, an anxiety disorder can develop, such as a phobia of dogs because they might suddenly bark, or agoraphobia (fear of public places) as home is a relatively safe and controlled sensory experience. Some social situations such as attending a birthday party may be avoided, not only because of uncertainty regarding the expected social conventions but also because of the noise levels of exuberant children and the risk of balloons popping.
THE DIAGNOSTIC ASSESSMENT
Signs are more conspicuous in early childhood and gradually diminish during adolescence, but can remain a life-long characteristic for some adults with AS. This is not included in any of the four diagnostic criteria for Asperger’s syndrome but should be included in future revisions especially as the consequences can have a significant effect on the person’s quality of life.
Some sensory experiences can be extremely enjoyable. Whether it causes pleasure or discomfort, the sensory world is certainly perceived differently by people with AS.
Assessment Instruments
The Sensory Behaviour Schedule – a 17-item screening questionnaire for children aged 5-11 designed to provide a brief description of sensory perception and behaviours.
The Sensory Profile – a 125-item questionnaire that measures the degree to which children from 5-11 exhibit problems in sensory perception, sensory modulation, behaviour and emotional responses to sensory experiences, and hyper- and hypo-responsiveness.
Short Sensory Profile – takes about 10 minutes for parents to complete.
Sensory Profile Checklist-Revised (SPCR) – extremely comprehensive assessment for children with autism and AS with 232 questions for parents to complete and is designed to identify remedial activities.
SOUND SENSITIVITY
Between 70-85% of children with AS have an extreme sensitivity to specific sounds. There are three types of noise that are perceived as extremely unpleasant.
1. Sudden, unexpected noise that could be described as ‘sharp’ – a dog barking, a telephone ringing, someone coughing, a school fire alarm, the clicking of a pen top, or cracking sounds.
2. High-pitched, continuous sounds, particularly the sound of small electric motors used in domestic electrical equipment such as food processors or vacuum cleaners or the high-pitched sound of a toilet flushing.
3. Confusing, complex, or multiple sounds such as occur in shopping centres or noisy social gatherings.
As a parent or teacher, it may be hard to empathize with the person, as the sounds are not perceived by typical people as unduly unpleasant. However, a suitable analogy is the noise of fingernails scraping down a school blackboard.
Quotations by people with AS illustrate the intensity of the sensory experience.
Temple Grandin. “Loud, sudden noises still startle me. My reaction is more intense than other people’s. I still hate balloons, because I never know when one will pop and make me jump. Sustained high-pitched noises, such as hairdryers and bathroom vent fans, still bother me, lower frequency motors do not.”
Darren White. “I was also frightened by the vacuum cleaner, the food mixer, and liquified because they sounded about five times as loud as they actually were. The bus engine started with a clap of thunder, the engine sounding almost five times as loud as normal and I had my hands in my ears for most of the journey. “
Therese Jolliffe. The following are just some of the noises that still upset me enough to cover my ears to avoid them: shouting, noisy crowded places, polystyrene being touched, balloons and airplanes, noisy vehicles on building sites, hammering and banging, electric tools, the sound of the sea, the sound of the felt-tip marker used to colour, and fireworks. Despite this, I can read music and play it and there are certain types of music I love. When I am feeling angry or despairing about everything, music is the only way to make me feel calm inside.
Liane Holliday Willey. High frequency and brassy, tin sounds clawed my nerves. Whistles, party noise makers, flutes and trumpets, and any close relative of those sounds disarmed my calm and made my world very uninviting.
Will Hadcroft. The anticipation of an unpleasant auditory experience can make me anxious. I was perpetually nervous, and frightened of everything. I hate trains going over railway bridges when underneath, I was frightened of balloons bursting, the suddenness of party poppers, and the crack made by Christmas crackers. I was very cautious of anything that might make an unexpected loud noise – thunder even more than the lightning that followed. Guy Fawkes Night also made me tense, although I loved watching the fireworks.
It is possible to use acute auditory sensitivity as an advantage – know when a train is due to arrive at a station several minutes before others can hear it. One child could hear the unique engine sound of every bus that had been near his home, and with his secondary interest in vehicle license plates, he could identify the number plate of the imminent but invisible bus. Some don’t like insects and can hear the noise of flying insects. Another trick is to change the volume of sounds around them – when some kids spoke, they could scarcely hear them and sometimes they sounded like bullets. This sensory ‘tune out’ may be due to being intensely preoccupied with an activity that the auditory signals do not interrupt the intense concentration, or whether they are due to a genuine temporary and fluctuating loss of the perception and processing of auditory information. When tested, some have better than average hearing and can hear frequencies that only animals normally hear. There is a fluctuation in awareness of sound.
To deal with auditory hypersensitivity, some learn to switch off or tune out certain sounds. With loud or confusing noise, they can’t modulate it, but have to shut is all out and withdraw, or let it all in like a freight train. When using telephones at an airport, they may be unable to screen out the background noise without screening out the voice on the phone. Other techniques include humming to block out the noise or focusing intently on a particular activity – a form of intense absorption, being ‘mesmerized’ – to prevent the intrusion of unpleasant sensory experiences.
Strategies to Reduce Sound Sensitivity
First, identify which auditory experiences are perceived as particularly intense. Some can then be avoided. For example, vacuum when the child has gone to school. If the scraping noise of chairs being moved in a classroom can not be tolerated, the sound can be eliminated by covering the legs with a felt cover.
Silicone earplugs are useful in situations known to be noisy, such as school cafeterias. Music can make them feel calmer inside when feeling angry or despairing of everything. Using headphones can camouflage the noise. Parents and teachers must be aware and try to minimize the level of sudden noises, reduce the background sounds and conversation, and avoid specific auditory experiences known to be unbearably intense. This can reduce anxiety and encourage concentration and socialization.
Sensory Integration Therapy was developed by occupational therapists using controlled and enjoyable sensory experiences for several hours a week, usually over some months. Auditory Integration Therapy identifies the frequencies to which the person is hypersensitive to provide a special electronic modulating and filtering device, but it is expensive and has had no empirical proof of effectiveness.
Some sounds are perceived as extremely pleasurable – specific theme tunes, the sound of a ticking clock, the tinkling of a piano, metal striking metal, or a piece of cut crystal and a tuning fork.
TACTILE SENSITIVITY
This occurs in over 50% of children with AS. It can be a particular type of touch, the degree of pressure, or the touching of particular parts of the body. Hugging can be particularly disagreeable. Being held can create a sense of losing control and being engulfed. Touch used in social greetings or gestures of affection may be too intense or overwhelming, a ‘tidal wave’ of sensation. Children with AS may fear the close proximity of other children due to the risk of an accidental or unexpected touch, and meeting relatives with hugs or kisses is perceived as being too intense.
Some objects cause more reactions – stiff things, satiny things, scratchy things, or things that fit too tightly. Even thinking about them, imagining them, visualizing them, or any time their thoughts find them may cause goosebumps, chills, and a general sense of unease. Wearing new underwear can be an issue and most have to habituate to different types of clothes taking hours to get accustomed. They buy everyday clothes and good clothes that feel the same. Having a limited wardrobe ensures consistency of tactile experience. A problem is having to wash them and their durability. Once a particular garment is tolerated, parents may need to buy several increasing sizes, to cope with washing, wear and tear and the child’s growth.
Particular areas of the body are more sensitive, usually the head, upper arms, and palms. Washing, combing, or cutting hair can cause distress. Haircuts can even be described as painful due to pulling on the scalp. This usually improves with time. The sound of cutting hair is perceived as a ‘sharp’ sound as it is the vibration of electric clippers. They react to the tactile sensation of cut hair falling on their face or shoulders. Young children can feel unstable sitting in a barber’s chair from not having one’s feet on the ground.
Water on their face can be unpleasant and showers may be preferred over baths. The sensation of water splashing their face can be unbearable. They can go weeks without bathing and are amazed that kids have a regular shower, even every day!
At school, there may be an aversion to glue on their hands, finger painting, using playdough, and dress-up activities due to the tactile sensation of the costumes. There can be an over-reaction to being tickled or unexpected touch on certain areas such as the base of the back.
Sensual and sexual relationships can be affected – everyday gestures of affection such as a reassuring touch on the forearm or an embracing hug may not be perceived as pleasant. The typical partner may resent the lack of enjoyment in response to affectionate touch and the rarity of such gestures from their partner with AS. A more intimate touch may be unpleasant, let alone enjoyable. This is a problem of sensory perception rather than a lack of love and commitment to the relationship.
Strategies to Reduce Tactile Sensitivity
Awareness of and not forcing the person to endure the experience should be avoided. They can play with toys and engage in educational activities that do not cause distress due to the child’s being tactile and defensive. The family should reduce gestures of affection used in greetings and let them know when and how they will be touched so that the sensation is not a total surprise and is likely to elicit a startle reaction. Remove tags from clothing. Encourage the child to tolerate hair washing and cutting and head massages or slowly but firmly rubbing the child’s head and shoulders with a towel can reduce scalp sensitivity. There may be greater sensitivity to light touch.
Temple Grandin found deep pressure or squeezing enjoyable and calming: “I would pull away and stiffen when hugged, but I craved back rubs. Rubbing skin has a calming effect. I craved deep-pressure stimulation. The pressure was very calming and relaxing. As a child, I loved crawling into small, snug places. I felt relaxed, secure, and safe.”
She designed a ‘squeeze machine’, lined with foam rubber, which enclosed almost her whole body and provided firm pressure. The soothing and relaxing experience gradually desensitized her.
Liane Holliday Willey found solace underwater. “I loved the sensation that came from floating with the water. I was liquid, tranquil, smooth; I was hushed. The water was solid and strong. It held me safe in its black, awesome darkness and it offered me quiet – pure and effortless quiet. Entire mornings would pass me by while I swam underwater for great periods of time, pushing my lungs to hold onto the quiet and dark until they forced me to find air.”
Having tactile defensiveness not only affects the person’s mental state, it also affects interpersonal relationships, as typical people often touch each other. The request ‘keep in touch’ may not be readily accepted by the person with Asperger’s syndrome.
SENSITIVITY TO TASTE AND SMELL
Children with AS often have a remarkable ability to detect odours that others do not notice and can be extremely fussy in their choice of food. Over 50% of children with AS have olfactory and taste sensitivity.
Sean Barron: “I had a big problem with food. I liked to eat things that were bland and uncomplicated. My favourite foods were cereal – dry, with no milk, bread, pancakes, macaroni and spaghetti, potatoes and milk. I found them comforting and soothing. I didn’t want to try anything new.
I was super sensitive to the texture of food, and I had to touch everything with my fingers to see how it felt before I could put it in my mouth. I really hated it when food had things mixed with it like noodles with vegetables or bread with fillings to make sandwiches. I could never, never put any of it into my mouth. I knew that if I did, I would get violently sick.”
Stephen Shore: “Canned asparagus was intolerable due to its slimy texture, and I didn’t eat tomatoes for a year after a cherry tomato had burst in my mouth while I was eating it. The sensory stimulation of having that small piece of fruit explode in my mouth was too much to bear and I was not going to take any chances of that happening again.
Carrots in a green salad and celery in a tuna fish salad are still intolerable to me because the contrast in texture between carrots or celery and salad or tuna fish is too great. I enjoy eating celery and baby carrots by themselves. Often as a child, less now, I would eat things serially, finishing one item on the plate before going on to the next.
The young child may insist on a plain or restricted diet – boiled rice or sausages and chips for every evening meal for several years. The sensitivity and subsequent avoidance of food that has a specific fibrous or ‘wet’ texture, and the combination of certain foods, can be the source of agitation for the whole family at mealtimes. Mothers in particular can be in a state of despair that the child will not contemplate any new or more nutritious food. Most are able to widen their diet as they mature, and for many children, this characteristic disappears by adolescence.
Tactile defensiveness may cause retching by putting a finger down their throat. The reaction is an automatic reflex to avoid a solid object in the throat, and the sensation is extremely unpleasant. They may have the same reaction to fibrous food in their mouth, not just the throat.
Sometimes the resistance to certain fruits or vegetables is due to heightened sensitivity to specific aromas. The aroma may be delicious to typical people, but the greater olfactory sensitivity and range of perception detect certain aromas as overly pungent. A peach may ‘smell like urine’ or ‘it smells as if it is rotten’.
Olfactory sensitivity can cause nausea with someone’s perfume or deodorant. Perfumes may have a similar smell to insecticides. They may avoid the aromas of paints and art supplies at school, the school cafeteria, or rooms where a cleaner has used a particular detergent or cleaning fluid.
The heightened sense of smell can have advantages. Some may combine an acute sense of smell with a special interest in wines to become celebrated wine experts and connoisseurs. Sometimes, they may warn another diner at another table that their seafood was off and would make her very ill. Some can use their ability to smell sickness in their children by smelling their breath.
Strategies to Increase Dietary Diversity
It is important to avoid programs of force-feeding or starvation to encourage a more varied diet. It is not a simple behaviour problem where the child is being deliberately defiant. Parents still have to ensure that their child eats an appropriate range of food, and a dietician may help with what is nutritious but tolerable for texture, aroma or taste. Gradually the sensitivity diminishes, but the fear and consequent avoidance may continue. A program of systematic desensitization can be introduced by first identifying the least unpleasant foods and more likely to be tolerated with encouragement. With a low preference for food, the child initially only has to lick and taste, rather than chew and swallow, the food.
Nevertheless, some adults continue a very restricted diet consisting of the same essential ingredients, cooked and presented in the same way, throughout their lives. At least the preparation may be very efficient through considerable practice.
VISUAL SENSITIVITY
Sensitivity to particular levels of illumination or colours, or distortion of visual perception occurs in about 20% with AS. They report being ‘blinded by brightness’ and avoid intense levels of illumination. They may refer to “bright days my sight blurred”. Occasionally, there may be a sensitivity to a particular colour: “I also remember one Christmas when I got a new bike for a present. It was yellow. I would not look at it. Extra red was added to the colour making it look orange, and it blurred upwards making it look like it was on fire. I also couldn’t see blue clearly, it looked too light and it looked like ice.”
There can be an intense fascination with visual detail, noticing specks on carpet or blemishes on someone’s skin. When the child with AS has a natural talent for drawing, and this is combined with a special interest and considerable drawing practice, the result can be works of art that achieve the effect of photographic realism. For example, a young child who has a special interest in trains can be precocious in learning to draw railway scenes in perspective, including almost every detail of the locomotive. In contrast, the people in the scene may be drawn at an age-appropriate level of representation.
There are reports of visual distortion. “I used to hate small ships because my eyesight used to make them look as if they were even smaller than they actually were.”
This can lead to fear or anxiety as a response to certain visual experiences: “It may be because things that I see do not always make the right impression that I am frightened of so many things that can be seen, people, particularly their faces, very bright colours, crowds, things moving suddenly, large machines and buildings that are unfamiliar, unfamiliar places, my own shadow, the dark, bridges, rivers, canals, streams, and the sea.”
Certain visual experiences can be confusing, for example, light reflecting on the classroom whiteboard effectively makes the text illegible and creates a disturbing distraction. “Bright lights, mid-day sun, reflected 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. My head would feel tight, my stomach would churn, and my pulse would run my heart ragged.”
“With fluorescent lights, it’s not only the glare that gets me, but it’s also the flicker as well. It produces ‘shadows’ in my vision (which were very scary when I was young) and long exposure can lead to confusion and dizziness often resulting in migraine.”
There have been descriptions of not being able to see something clearly visible and that the person is searching for – the natural phenomenon of not seeing something ‘right before your eyes.’ The child may not be able to find a book easily done by others to see. This can be infuriating for the child and the teacher.
Some visual experiences can be intensely pleasurable, especially with visual symmetry. For young children, this can be parallel lines and sleepers or ties of a railway track, a picket fence or electricity pylons in a rural landscape. Adults with AS may extend their interest in symmetry to an appreciation of architecture.
Lynn Holliday Willey: “Design may be a favoured subject, bring joy and be the perfect elixir for whatever ails me. When I feel tangled and tense, I get out my history of architecture and design books and set my eyes on the kinds of spaces and areas that make sense to me; the linear, the straight-lined, and the level buildings that paint pictures of strong balance.
Several famous architects may have had some of the personality characteristics associated with Asperger’s syndrome. However, the appreciation of the symmetry of buildings can be a disadvantage. Buildings that are asymmetrical or “jagged” in design make them nauseous and very anxious.
Strategies to Reduce Visual Sensitivity
Strategies include not seating the child on the side of the car that receives the full glare of the sun, or at a school desk illuminated by strong sunlight. Use of sunglasses and visors indoors can reduce intense light or glare, or have a workstation to screen out excessive visual stimulation. A natural screen can be produced with long hair that acts as a curtain and barrier to visual (and social) experiences. Perceived intensity of colours may lead to a preference for wearing only black clothes, which is not necessarily a fashion statement.
Remedial programs use tinted glasses to improve visual perception and reduce perceptual overload and visual disturbance. Tinted non-optical lenses (Irlen filters) are designed to filter out those frequencies of the light spectrum to which the person is sensitive.
Vision therapy can ‘retrain’ the eyes and the structures in the brain that process visual information. An assessment is made of potential visual dysfunction and may compensatory mechanisms, such as tilting or turning the head, using peripheral vision, and preferring to use one eye.
If the person with AS is extremely distressed or agitated, they benefit from an area or room to retreat into and calm down, away from other people. It should be sensorily calming and soothing – the symmetry of furnishings, the colours of the walls and the carpet, and no sounds, aromas, or tactile experiences that are perceived as unpleasant.
THE SENSE OF BALANCE AND MOVEMENT
Problems with the vestibular system can cause problems with a sense of balance, perception of movement, and coordination that could be described as ‘gravitational insecurity – becoming anxious if their feet leave the ground, and feeling disoriented when having to change body position rapidly, as required in ball games such as soccer. It may be extremely uncomfortable when upside down.
Lynn Holliday Willey: “Motion is not my friend. My stomach tips and spills, when I look at a merry-go-round or drive my car over a hill or around a corner too quickly. When my first baby was born, I soon learned my troubles with vestibular motion went beyond amusement parks and car rides. I could not rock my girls. I could sway, though, and this I did even in my rocking chair.”
However, some children with AS experience extreme pleasure when on a roller-coaster, to such an extent that roller coasters become a special interest. They are great to listen to and watch.
THE PERCEPTION OF PAIN AND TEMPERATURE
People with AS may appear very stoic, and not show distress to levels of pain that others find unbearable. How a bruise or a cut occurred may not be remembered. Splinters may be removed without distress. On hot days, warm clothing may be worn, or on freezing winter days the person may insist on wearing summer clothes. It is as if they have an idiosyncratic internal thermostat.
There can be a hypo- or hypersensitivity to pain. The low threshold for some types of pain and discomfort can be a source of distress when their reaction is judged by peers as being a ‘crybaby. However, children with AS are more likely to be hypo than hypersensitive.
“Two years ago my son came home with a badly scraped leg, heavily bruised with numerous cuts, but he said “there is nothing wrong, it doesn’t hurt and “it happens all the time” and proceeded to go to his bedroom. This was a common occurrence over the 18 years. He also does not feel cold like others. In the winter, he rarely wears a jacket and wears short sleeves to school, and feels very comfortable.
Atwood met a man in Australia. The temperatures were below zero and everyone except the young man was complaining about how cold they were feeling and wearing many layers of warm clothing. He was only wearing a T-shirt and refused offers of warm clothing. He explained that he was comfortable but he made everyone else feel uncomfortable.
Carolyn: My response to pain and temperature seems to be similar to my response to trivial or traumatic events. At low levels of stimulation, the response is exaggerated and it can dramatically hamper my ability to function, but at higher levels, the senses seem to shut down and I can function better than normal. I can think logically and act calmly and efficiently when others would panic in the same situation.
Asperger noted that one in four children he saw was late in being toilet trained. It is possible that they were less able to perceive the internal signals of bladder and bowel discomfort to prevent ‘toileting accidents’. The lack of reaction to discomfort, pain, and extremes of temperature can also prevent the young child with AS from learning to avoid certain dangerous actions, resulting in frequent trips to the local casualty department. Medical staff may be surprised at the audacity of the child or consider the parents negligent.
One of the most worrying aspects for parents is how to detect when the child is in chronic pain and needs medical help. Ear infections or appendicitis may progress to a dangerous level before being detected. The side effects of medications may not be reported. Dental and menstrual pain may not be mentioned. One child seemed not his usual self and had a twisted testicle that had to be removed. It is vital to explain to the child why reporting pain to an adult is vital to help them feel well again and avoid more serious consequences.
UNUSUAL SENSORY PROCESSING
Synaesthesia, a rare form of sensory perception, is where the person experiences a sensation in one sensory system, yet perceives the sensation in another modality. The most common expression is to see colours every time they hear a particular sound (coloured hearing), or perceive a specific aroma. Specific sounds may come through as vague sensations of colour, shape, texture, movement, scent, or flavour. Some search for words that tickle, words that have smooth textures, and words that warm when they speak them.
Auditory stimuli may interfere with other sensory processes. They may have to turn off kitchen appliances to taste something. There may be difficulty identifying the source channel of sensory information. They may know that something is coming in somewhere, but can’t tell right away what sense it’s coming through. The experience must be quite bewildering.
Liane Holliday Willey explains her sensory perception and living in ‘surround sound’:
“I think my girls have learned to accept the public me without too much pain and embarrassment. Sure, they remind me not to talk to myself in public, not to use a loud voice around others, not to bring up the subject of my dogs to every living soul, not to ramble on in my conversation, not to cover my ears at the park and yell “who in their right mind can stand all this noise!” But that is just fine with me, for all along the way, they never, ever forget to tell me that despite all of my quirks and batty nuances, they love me no matter what.”