What is Sensory Processing?
The Basics:
What is it? What does this terminology sensory processing mean? Suddenly you’ve heard these words and you want to know more about what is specifically means. Sensory processing refers to how your body receives sensory information. When sensory information is received the human body has receptors that receive information and via transmitters send that information to the brain. The brain takes this information, decodes and interprets this information, and then tells your body to react to that information.

The brain is like a computer and requires certain types of input, specifically sensory input to power the brain and allow the body to function in a variety of settings and situations. The brain needs this input to be received in a detailed and organized manner so that it can be processed and interpreted appropriately. Sensory input includes: hearing, vision, touch, taste, smell, vestibular/movement, and proprioception.

The structures within the inner ear, specifically the semi-circular canals, detect movement and changes in head positioning. These structures are what comprise the vestibular system. This system is responsible for coordinating eye, head, and body movements. As well, it influences praxis (motor planning), bilateral coordination, muscle tone, movement and balance, appropriate head positioning, and auditory language processing.

There are receptors in the muscles, tendons, and joints that are responsible for the proprioceptivesensory system. These receptors are critical for telling our body where it is in space. This information is automatic and constant. Typically, we do not consciously think about where we are in space or how we are going to move our bodies unless we have decreased proprioceptive sensory processing skills. If this occurs, we present with poor body awareness and often appear clumsy. A person with poor proprioception often trips and falls, bumps into things, walks over things, drops things, and has poor social spatial boundaries (gets too close too people or needs increased personal space). The tactile sensory system, also known as the touch system is quite complex.

The tactile system is made up of skin receptors under the surface of the entire body. The tactile sensory system includes the protective system and the discriminatory system. The protective system is part of our nervous system’s flight or fight response. It alerts us to various levels of touch, if something is dangerous, whether or not something is hot or cold, or if our body is experiencing pain. When the tactile sensory processing system is misinterpreting information, someone will demonstrate inappropriate responses to touch. They may be sensitive to touch, and light touch may even be interpreted as painful, or pain may not even be registered or responded to. The discriminatory tactile sensory processing system provides the body with information about what we are touching without using our visual sensory system, where the touch is occurring on the body, and where our body is moving.

The tactile system connects to many different areas of the brain. As a result, dysfunction that occurs in the tactile sensory processing system often affects sleep/wake cycles, emotion and behavior, spatial concept skill development, sequencing, fine motor skills: grasping and manipulative skills, and gross motor skill development.

The vestibular, proprioceptive, and tactile sensory systems are critical for higher level learning to occur. This foundation of these systems is necessary not only for higher-level thinking, but also for typical development and ease with daily activities. If there is dysfunction in any of these systems, the foundation for higher learning is impeded.

Neurologically, there are important concepts regarding the correlation of sensory processing skills, developmental growth, and higher-level learning.
• While a baby is in utero, the baby’s brain continues to grow and develop.
• After a baby is born, the brain continues to grow and develop.
• The brain’s growth and development is dependent on the sensory input it receives
• The sensory-enriched brain thrives and develops the foundations for higher learning. (Adapted from Lorna Jean King).

When sensory processing dysfunction occurs, it is necessary and detrimental for a the appropriate intervention of a sensory based evaluation to be completed by an occupational therapist skilled in working with babies, children, and adults struggling in this area. The evaluation and plan of treatment should be formulated in conjunction with the child’s family and direct caregivers.

SENSORY PROCESSING DISORDER: When a child presents with challenges with their sensory processing skills that are resulting in developmental delays in a variety of skills, such as: play, communication, self-help skills, self-regulation, fine and gross motor skill development; then the child may be diagnosed with having sensory processing disorder. Sensory processing disorder often affects a child’s behavior, their ability to learn, their ability to move, their ability to communicate and connect with others, and their self-image.

According to Dr. Lucy Jane Miller, Sensory Processing Disorder is comprised of three main categories with specific subtypes for each category.  Please refer to Miller, Lucy Jane with Fuller, Doris A.: Sensational Kids: Hope and Help for Children with Sensory Processing Disorder (SPD), New York, New York, 2006, the Berkley Publishing Company, (pp. 12 and 31).  

Sensory Modulation Disorder (SMD):

    • Sensory Over-Responsivity (SOR) -“SOR is a problem with turning sensory messages into controlled behaviors that match the nature and intensity of the sensory information” (Miller et al. 2006).  Children with SOR usually present with “adverse reactions to tactile, visual, oral (taste and feel), olfactory (smell), and auditory sensory input. SOR can be present in children with SMD that exhibit SUR and SC symptoms” (James et al. 2011).
    • Sensory Under-Responsivity (SUR) -Children with SUR often present with “movement sensitivity, emotional withdrawal, low energy and/or weak muscles, fatigue, poor balance and motor control. These behaviors may occur because children with SUR tend to avoid activities that challenge their balance and motor coordination”(James 2011). 
    • Sensory Craving (SC) -Children with SC behaviors, also described as “ ‘sensory seeking’ are often characterized as presenting with “hyperactivity, impulsivity, delinquent and/or aggressive behaviors, poor socialization, inability to adapt, and impaired cognitive and/or social behaviors” (James et al. 2011)     
    Sensory Based Motor Disorder (SBMD):

    • -“SBMD is a problem with stabilizing, moving or planning a series of movements in response to sensory demands” (Miller et al. 2006). 
      • Dyspraxia -“Children with dyspraxia have difficulty translating information into physical movement, unfamiliar movements, or movements with multiple steps” (Miller et al. 2006). 
    • Postural Disorder -“Children with postural disorder have difficulty maintaining enough control of their bodies to meet the demands of a given motor task” (Miller et al. 2006).
    • Sensory Discrimination Disorder (SDD) -“SDD is a problem with sensing similarities and differences between sensations” (Miller et al. 2006).
      • Visual  
      • Auditory 
      • Tactile 
      • Taste/Smell 
      • Position/Movement
      • Interception  
    Sensory processing challenges are suspected when a child exhibits a bundle of symptoms in one or more of the following sensory systems:

      • Craves movement: “constantly on the go”, difficulty sitting still, spins self  
      • Difficulty attending to sit-down structured tasks 
      • Fearful of having feet off of the ground: dislikes being tossed in the air or riding on swings 
      • Avoids movement based activities, such as: running, carnival rides, swings 
      • Clumsy, easily trips and falls 
      • Poor bilateral coordination: difficulty using both sides of the body together for success for fine and gross motor tasks 
      • Poor spatial judgment during gross or fine motor activities 
      •  Poor posture: Often slumps forward, slouched, head looks down 
      • Often “w” sits 
      • Often moves in “end range of motion” patterns, use of extension and hyperextension when creeping and walking 
      • Stiff rigid movements 
      • Child often walks on tiptoes and or on toes curled 
      • Child may frequently seek out intense activities like jumping and crashing, climbing, jumping, rough and tumble play 
      • Decreased spatial awareness of where child is in their environment 
      • Poor spatial boundaries when around others: lean on people, get too close 
      • Increased need for space, won’t allow people to get too close 
      • Decreased spatial awareness with fine motor tasks, such as letters/drawing 
      • Does not like to be touched or is always touching something
      • May not like to be hugged or sit on your lap 
      • May always want to be held, hugged, and touched 
      • May not like to get messy with finger paints, get dirty, or play with play dough 
      • May seek out “messy” activities and smear “messy” modality all over self and surroundings 
      • May be sensitive to certain types of clothing: texture, tightness, season, tags, etc. 
      • May dislike having hair and/or nails trimmed 
      • May love water or be fearful of the water
      • May not like certain textures outside: grass, sand, mud, mulch, snow, water, etc. Alternatively, may love these things and can’t get enough
      • May be sensitive to wet or messy diapers, may be unaware of wet or messy diapers
      • May inappropriately put nonfood items like toys and unsafe environmental objects in mouth, when past teething/mouthing stage 
      • May grind teeth and/or clench jaw
      • May suck on thumb, fingers, hand, or clothing 
      • May eat foods with increased intensity: lemons, sour candies, spicy foods, ice cubes 
      • May have difficulty weaning from bottle and/or pacifier
      • May be sensitive to different textures of food: May only eat pureed foods when should be eating table foods, may only eat textured foods and avoid pureed foods, may avoid mixed textured foods or foods of certain colors or foods of different temperatures 
      • May gag just at visual sight of food or by touching the food
      • May put too much food in mouth, over-stuffing, to point of coughing, choking, gagging
      • May avoid eating all together
      • May resist sitting for meals
      • May resist having teeth brushed
      • May have problems that result in emesis or holding bowels (have to rule out medical causes for this) 
      • May be sensitive to certain smells: food, environmental
      • May seek out smells: special blanket, mom’s shirt or hair, etc. 
      • Seeks out visual sensory input by spinning things, flapping hands, looking out of the corner of eyes, dangling objects
      • Fixates on lights: stares at lights, turn lights on/off
      • Fixates on moving things: ceiling fans, toys that move, vacuum, etc.
      • Sensitive to visual sensory input, and therefore avoids eye contact
      • Sensitive to environments with lots of visual stimuli, prefers dark rooms with decreased lighting 
      • Eyes may tire easy, and therefore avoids visual activities
      • May have poor visual motor coordination, resulting in struggles with fine and gross motor activities
      • May demonstrate poor handwriting
      • May have decreased interest in books
      • May have difficulty with reading
      • Visual spatial and visual perceptual challenges 
      • Fearful of loud, environmental sounds like the vacuum cleaner, blender, dog barking
      • Fearful of big buildings or gymnasiums where there is an echo
      • May easily startle
      • May not respond to environmental sounds: loud or soft
      • May not be able to follow directions: simple or complex
      • Decreased response to name
      • May prefer music that is simple with a strong rhythmic beat and decreased treble component 
    When a child is suspected of having sensory processing challenges a specialized evaluation by a pediatric occupational therapist is recommended. An evaluation is typically completed using standardized tests, clinical observation, and parent report. Occupational therapists will evaluate a child’s sensory processing skills, fine motor skills, muscle strength, muscle tone, eye movements and visual motor skills, balance, coordination, and motor planning. The results of the evaluation will determine if the child needs an individualized treatment plan and ongoing services to focus on the child’s strengths and areas of need.

    The treatment plan consists of activities that focus on utilizing a multi-sensory play based approach using a “just right” challenge to engage the child in a playful environment. The idea is for the child to  be challenged while successfully learning to adapt to a variety of settings and situations; and have fun while doing so.