Your everyday experience of and interactions with our world are shaped by the input received through your senses. While each one of us can be quirky or particular about our likes and dislikes, individuals with Sensory Processing Disorder (SPD) are so severely affected by their sensory experience that their preferences for interacting with their environment and the people in it disrupt their everyday functioning to varying degrees.
Sight, hearing, taste, smell and touch are not your only senses. Our whole sensory experience incorporates the perception and interpretation of balance, pain, temperature, kinesthesia or movement, vibration, and various internal sensings by different chemoreceptors for blood saturation which result in your precepts of hunger, satiety, and thirst. Efficient processing and effective integration of all these stimuli determine our degree of comfort in experiencing life.
SPD is a condition where the messages the brain takes in through the eyes, ears, nose, mouth, muscles, joints, skin, inner ears, and internal receptors are unusually experienced, interpreted, and organised, leading to ranging degrees of discomfort in the experience of everyday life. Indeed, diagnosis of SPD is made difficult by the varied — and often contradictory — manifestations, which range from the brutality of sensory overload to the overwhelming craving for sensory stimulation.
For those experiencing life with SPD, there follows extreme emotional and behavioural reactivity. What these emotional and behavioural reactions to sensory experience have in common is their sudden onset and unpredictability. This makes a person living with SPD experience life in a perpetual state of fight, flight, or freeze in reaction to stimuli. This can lead to living in constant fear of the onset of those reactions, so causing depression and anxiety disorders. SPD takes a high toll on the individual, parents, and loved ones alike, being profoundly disruptive on every level of daily functioning.
Knowing SPD’s neuro-structural, functional, and genetic underpinnings would allow for new therapeutic targets and new ways to measure the success of therapeutic interventions. The goal of burgeoning SPD research is to understand the relationship between the differences in SPD individuals’ brains and their autonomic nervous systems – that part of the nervous system controlling breathing, digestion, heartbeat, and the fight-or-flight response, which, for folks with SPD, can feel like their resting state. More often than not, their reactions and behaviours cause others to experience them as antisocial and misanthropic. This is not the case at all: folks with SPD are wanting to socially engage, crave interpersonal connection as much as anybody else — they just can’t tolerate it.
The most common traits of folks experiencing life with sensory processing and integration problems are more easily understood in terms of over-responsiveness (hypersensitivity) or under-responsiveness (hyposensitivity) to sensory stimuli; or as contextual issues of sensory discrimination (like separating the sound of a person speaking from background noise, or applying enough pressure to hold a glass without dropping or crushing it). Below are a few recognisable traits of people experiencing life with Sensory Processing Disorder.
Over-responsive traits could include:
- Discomfort or distress is experienced when their feet are off the ground; fearful of climbing over obstacles or falling off objects, experiencing vertigo – particularly when there is no actual danger in their environment
- Pain is experienced from soft touch, making them fearful of surprise touch; avoiding hugs and cuddling even with lovers, friends, and family
- They have an extreme fright response to sudden sound, high-pitched, loud, or metallic noises in particular. The bus pulling into the bus stop, a car door slamming, a flushing toilet, clanking silverware, and other noises that seem unoffensive to others, can bring about a disturbing reaction in them
- Sound, proximity, and temperature hypersensitivity make them fearful of social gatherings and crowds, avoiding getting close to others
- Problems with kinaesthesis (the ability to feel movement in the limbs and body) cause inadequate coordination and poor balance, and they may take falls often
- Sounds in the background – that others do not seem to hear – can overwhelm them, the consuming sound drowning out all other sounds, disrupting focus and comprehension, making it impossible to listen and participate in a conversation
- Some avoid contact sports or are overly fearful of gym and sports equipment since they come to associate such with unbearable discomfort and pain
Under-responsive traits could include:
- Often consumed by the desire to move, they can be fidgety, unable to sit still and enjoy movement-based games and extreme sports like bike racing, sky diving, swimming, spinning, etc.
- Dampened ability to feel movement in the limbs and body cause clumsy and uncoordinated movements and they often drop items and trip up on uneven surfaces
- A constant desire and need to touch people, or specific textures and particular coloured objects — their behaviour in this regard is often considered socially inappropriate, causing them great social anxiety
- Extremely high tolerance for pain or total indifference, causes them to pick up scratches, cuts, and bruises that can have serious health repercussions. They often have to avoid contact sport since they are unable to gauge potential injuries.
- Some folks are unable to understand the social norms of personal space and physical contact; their interpersonal behaviour is often misconstrued as rude or lascivious
- Often they cannot regulate their strength, accidentally hurting others, children, or pets when trying to make physical contact. This can lead to being fearful of physically touching someone, an animal, or something perceived as delicate
- Hyposensitive individuals are often seen by others as “thrill-seekers’ that regularly engage in “dangerous” pastimes themselves being considered “dangerous” in certain circumstances
A person experiencing life with SPD can present traits individually or in combination. Just as they are individuals — each with unique physiology of sensory differences — their SPD experiences are unique and should be regarded as a function of their singular brain structure and brain activity that is guided by both genetic and environmental influences.
“Their brains are wired differently”, says Dr Elysa Marco, a cognitive and behavioural pediatric neurologist at University of California San Francisco (UCFS) Benioff Children’s Hospital San Francisco and a member of the UCSF Weill Institute for Neurosciences. Marco contributes to breakthrough research investigating the biological basis for Sensory Processing Disorders. The data from the first study of this nature is clear: Individuals with sensory processing differences just have different degrees of connection efficiency, particularly in the back part of the brain. This study was the first to reveal that people with SPD have quantifiable and distinct differences in brain function; published in the open-access online journal NeuroImage:Clinical.
Experiencing life with SPD can be profoundly life-affecting for the individual, their family, relationship partners, and friends. Notwithstanding this, the disorder isn’t unmanageable or untreatable. With understanding, loving support, and a little help, those who live with SPD can enjoy completely regular lives through learning how to manage their environmental reactivity and limiting exposure to trigger stimuli.
If you enjoyed reading about Sensory Processing here, go check out these two great Psych2Go posts about human sensation:
- Are You Oversensitive To Sound? You May Want To Know About Misophonia.
- Synesthesia: Senses Joined Together
Psych2Go will provide more insight into Sensory Processing Disorder in the follow-up post, Why Do Some Individuals Find Everyday Stimuli Excruciating: Scientific Research Expands Our Understanding.