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What is Sensory Processing Disorder (SPD)

Sensory Processing Disorder (SPD, formerly known as "sensory integration dysfunction") is a condition that exists when sensory signals don't get organized into appropriate responses. Pioneering occupational therapist and neuroscientist A. Jean Ayres, PhD, likened SPD to a neurological "traffic jam" that prevents certain parts of the brain from receiving the information needed to interpret sensory information correctly. A person with SPD finds it difficult to process and act upon information received through the senses, which creates challenges in performing countless everyday tasks. Motor clumsiness, behavioral problems, anxiety, depression, school failure, and other impacts may result if the disorder is not treated effectively.

There are 3 levels of Sensory Processing Disorder (SPD)

The 1st level is mild, they will appear “normal”, but picky or over sensitive, or even resistive to change and slightly controlling.

The 2nd level is moderate. A moderate sensory defensiveness will affect 2 or more aspects of a child’s life. They may often have difficulties with social relations, either overly aggressive or isolating themselves from peers. They may be resistive to dressing, bathing and eating. In school they may have difficulty with attention or behavior.

The 3rd level is severe. With the severe level, every aspect of a child’s life is disrupted. They usually will have other diagnostic labels such as developmental delay, autism, etc. These children may have a strong avoidance of some kinds of sensations or the reverse, intense sensory seeking.

Children can over- or under- react to their eight sensory systems with sensory modulation disorder.

Hypersensitive / over-reactive: children who receive more than normal sensory signals and seek the input from the sensory system.

Hyposensitive / under-reactive: children who are under-responsive to sensory signals and avoid the input from that sensory system.



The body’s spatial awareness tool, conducted by the inner ear. The vestibular system allows us to maintain our body’s orientation and balance and helps it remain in control when in movement.

Over-reactive –> fear of heights, impulsive or constant movement, seeking to be upside down, motion sickness {me! in a car, plane, on a swing, anywhere!}

Under-reactive –> difficulty standing or sitting still, fear of movement activities or being upside down, claustrophobia, may seem clumsy, difficulty with stairs or rigorous exercises, lack of coordination


How the body interprets nerve receptors on the skin, this includes: light touch {surface}, deep touch {pressure}, temperature, and pain, feeling vibrations and pressure through physical, discriminative touch. Ability to feel pain {itching or tickling} or temperature, move muscle, tendon, and joint position and stretch is proprioception. And ability to use motor skills and develop visual and body awareness.

Over-reactive –> defensive to touch, bothered by loose clothing or tags, cannot sit still, continuous movement, impulsive behaviors, motion sickness {me! in a car, plane, on a swing, anywhere!}

Under-reactive –> need to touch, desires to be touched


This sensory system allows the body to regulate muscles and joints to allow for movement and body position. Allows the body to be aware of motion, acceleration, motor control, and posture.

Over-reactive –> cannot sit still, continuous movement, impulsive behaviors

Under-reactive –> fear of movement activities or being upside down, may seem clumsy, difficulty with stairs or rigorous exercises, lack of coordination


This sensory systems does not have to do with eyesight or vision, but is rather the brain’s ability to properly process the visual environment to perceive and to discriminate visual input.

Over-reactive –> sensitive to the sun and light, distracted by too many things around them {i.e. a classroom wall}

Under-reactive –> cannot look someone in the eye, difficulty reading words on a page, dyslexia 


The body’s ability to discriminate between sounds and sort through their hearing processes. Being able to focus attention on the most important sound among lesser ones, as well as to distinguish between words and to follow instructions.

Over-reactive –> sensitive to loud sounds and background noises

Under-reactive –>


How the brain deciphers between pleasant and odorous smells, while aiding or inhibiting our ability to eat {gustatory}, to focus, or to remember information.

Over-reactive –> sensitive to smell

Under-reactive –> will overtly smells things around them


The mouth’s ability to process temperature, taste, and texture while eating, as well as the body’s proprioceptive {muscle} response to eating for nourishment and pleasure.

Over-reactive –> picky eaters, sensitive to teeth brushing

Under-reactive –> chewing on pencils, fear of movement activities or being upside down, may seem clumsy, difficulty with stairs or rigorous exercises, lack of coordination


The body’s eighth sensory system is not discussed at length in many places; it is the body’s nerve response to digestion or respiration.

Over-reactive –> seeking fast heartbeat through rigorous exercise, taking large breaths, not eating due to liking the sensation of hunger, always potty-ing

Under-reactive –> eating more often to avoid hunger pangs, slow to potty train, avoiding fast breathing or heartbeat

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