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 mended socks. Washing water can be unpleasant. There is hypersensitivity to noise in specific situations, as well as 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 specific sounds, but tactile, light, taste, and texture sensitivities to food, as well as particular aroma sensitivities, can also occur. There can be an under- or overreaction to pain and discomfort, and the sense of balance, movement perception, and body orientation can be unusual. Every day, sensations are perceived as unbearably intense or 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 that 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 escape 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 with balance may cause a fear of having their feet leave the ground or a dislike of being held upside down.
In contrast, there can be a lack of sensitivity to particular sensory experiences, such as failing to respond to specific sounds, a failure to express pain when injured, or an apparent lack of need for warm clothing in icy winter conditions. 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 noise, echoing fluorescent lights (a particular source of visual and auditory stress for people on the autistic spectrum), ringing bells, people bumping into one another, and the smells of cleaning products, among other things. 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, and is 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 sensory experiences. The fearful anticipation can become so severe that 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 due to 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 lifelong characteristic for some adults with AS. This is not included in any of the four diagnostic criteria for Autism Spectrum Disorder (ASD), which includes Asperger’s syndrome. Still, it should be included in future revisions, especially since the consequences can significantly impact a person’s quality of life.
Some sensory experiences can be 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, provides 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. Three types of noise are perceived as highly 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 those that occur in shopping centres or noisy social gatherings.
As a parent or teacher, it may be hard to empathize with the person, as typical people do not perceive the sounds as unduly unpleasant. However, a suitable analogy is the sound of fingernails scraping down a blackboard in a school.
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 that of others. 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 the liquified because they sounded about five times as loud as they were. The bus engine started with a clap of thunder, sounding almost five times as noisy, and I had my hands over 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; there are certain types of music that 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 crackling 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 listen to the unique engine sound of every bus near his home. With his secondary interest in vehicle license plates, he could identify the number plate of the imminent but invisible bus. Some people dislike insects and can be bothered by 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 prevents auditory signals from interrupting intense concentration, or whether it is due to a genuine, temporary, and fluctuating loss of perception and processing of auditory information. When tested, some individuals have better-than-average hearing and can detect frequencies that are usually only audible to animals. 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; instead, they have to shut it 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, could you 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 helpful in situations known to be noisy, such as school cafeterias and other loud environments. Music can help them feel calmer when they are angry or despairing about everything. Using headphones can camouflage the noise. Parents and teachers must be aware of and try to minimize the level of sudden noises, reduce background sounds and conversations, and avoid specific auditory experiences known to be unbearably intense. This can help reduce anxiety, encourage concentration, and promote socialization.
Sensory Integration Therapy was developed by occupational therapists who use controlled and enjoyable sensory experiences for several hours a week, typically over several months. Auditory Integration Therapy identifies the frequencies to which the person is hypersensitive and provides a special electronic modulating and filtering device. However, it is expensive and lacks empirical proof of effectiveness.
Some sounds are perceived as extremely pleasurable, such as specific theme tunes, the sound of a ticking clock, the tinkling of a piano, the sound of metal striking metal, or the resonance of 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 specific 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 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, or visualizing them may cause goosebumps, chills, and a general sense of unease, regardless of the time or place. Wearing new underwear can be an issue, and most people 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 is also a concern. Once a particular garment is tolerated, parents may need to buy several clothes of 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 because they lack a stable base with one foot 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 activities such as finger painting, using playdough, and dress-up due to the tactile sensation of the costumes. There can be an overreaction to being tickled or an unexpected touch on specific 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 tactile and defensive nature. The family should reduce the frequency of affectionate gestures 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. Head massages or slowly but firmly rubbing the child’s head and shoulders with a towel can also help 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, 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, but 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 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 salad are still intolerable to me because the contrast in texture between carrots or celery and the salad or tuna is too great. I enjoy eating celery and baby carrots on their own. Often, as a child, I would eat things serially, finishing one item on the plate before moving on to the next.
The young child may insist on a plain or restricted diet, such as boiled rice, sausages and chips for every evening meal, for several years. The sensitivity and subsequent avoidance of food with a specific fibrous or ‘wet’ texture, as well as the combination of certain foods, can be a source of agitation for the whole family at mealtimes. Mothers, in particular, can be in a state of despair that their child will not consider any new or more nutritious food. Most can 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 highly unpleasant. They may have the same response 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 those with greater olfactory sensitivity and a wider range of perception may 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 from 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 detect sickness in their children by smelling their breath.
Strategies to Increase Dietary Diversity
It is essential 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 need to ensure that their child eats a balanced range of foods, and a dietitian may help determine what is nutritious and tolerable in terms of 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 those most 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 to adhere to 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 approximately 20% of individuals 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 appear orange, and it blurred upwards, giving the impression that it was on fire. I also couldn’t see blue, it looked too light, and it looked like ice.”
There can be an intense fascination with visual detail, noticing specks on the 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 were.”
This can lead to fear or anxiety as a response to specific 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 flicking, large machines and buildings that are unfamiliar, unfamiliar places, my own shadow, the dark, bridges, rivers, canals, streams, and the sea.”
Specific 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 bothers me, but also the flicker. 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 being unable to see something that is visible, and the person is searching for the natural phenomenon of not seeing something ‘right before your eyes.’ The child may struggle to find a book that others have found easily. This can be infuriating for the child and the teacher.
Some visual experiences can be intensely pleasurable, especially when accompanied by visual symmetry. For young children, this can include parallel lines and sleepers 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 exhibited some of the personality characteristics associated with Asperger’s syndrome. However, the appreciation of a building’s symmetry can be a disadvantage. Buildings that are asymmetrical or “jagged” in design can make people feel nauseous and 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. Using sunglasses and visors indoors can reduce intense light or glare, or having 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 utilize tinted glasses to enhance visual perception and mitigate 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 include 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 issues 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 highly 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 riding 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 peers judge their reaction 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 often wears short sleeves to school, feeling 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 felt, 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. However, 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 were late in being toilet-trained. It is possible that they were less able to perceive the internal signals of bladder and bowel discomfort, which could have prevented ‘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 specific 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 did not seem 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 crucial to help them feel well again and avoid more serious consequences.
UNUSUAL SENSORY PROCESSING
Synaesthesia, a rare form of sensory perception, is a condition where a person experiences a sensation in one sensory system but perceives it 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 with smooth textures, and words that warm when spoken.
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 which sense it’s coming through. The experience must be pretty 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.”
