Sensory Processing Disorder (SPD)
What is Sensory Processing
The diagram above illustrates how everyone functions better when they are in their “optimal stimulation band”. This means that they are registering enough sensory input to be aware of their environment but not so much that it becomes aversive.
Everyone’s sensory arousal level varies throughout the day, but those with Sensory Processing Disorder have either a low aversion threshold (making everyday sensory stimulation aversive to them), a high orientation threshold (so sensory stimulation that registers for most people does not for them), or both. These differences make it difficult for these individuals to stay in that “optimal stimulation band”, in which they would be able to function more effectively.
Our bodies need a certain amount of sensory input, especially proprioceptive, vestibular, and tactile input. If we are not getting enough, our bodies are unable to attend to, and learn from, our environment. Sensory input engages the lower part of our brain (cerebellum) which sends messages to the reticular activating system (RAS) located in the brain stem. The RAS plays a large role in our ability to attend to our environment.
People who don’t understand the underlying sensory causes for behaviors such as fidgeting or inattentiveness often try to solve the problem by repeatedly telling the child to “stop fidgeting” or “pay attention” (top-down approach). This response is likely to make children feel bad about themselves, which in turn can lead to emotional and behavior problems that result in decreased social, emotional, and academic success.
Instead of taking a top-down approach and having our brain’s cortex yell at our body to settle down and focus, it is more efficient, more sustainable, and much less painful for all involved if we take the bottom-up approach: figure out the underlying need that is leading to the behavior and meeting that need . At Porter Academy, we utilize sensory diets and classroom sensory tools to meet the sensory needs of all of our students. Sufficient sensory input enables the brain to be more efficient in processing sensory stimuli and prevents higher level brain structures from being preoccupied with meeting lower level sensory needs. As a result, higher level cortical areas can concentrate on academic tasks.
SPD impacts functioning in one or more of the folllowing ways:
- Sensory Modulation Problems: a problem with inhibition-excitation balance
- over-responsive; avoids certain sensory input
- under-responsive; seeks extra sensory input
- Sensory Discrimination Problems: brain mutes/magnifies messages inappropriately and cannot discriminate magnitude of sensory stimuli
- Difficulty distinguishing one sensation from another, interpreting a particular sensation, and misgauging the importance of objects and experiences.
- Sensory-Based Motor Problems
- Postural disorder: low muscle tone, bilateral coordination impairment, equilibrium problems, “W” sitting on floor, clumsiness, impaired grip strength
- Dyspraxia: difficulty performing voluntary coordinated activities
The Sensory Systems
- Vestibular: Input to the vestibular systems comes through the inner ear and provides information regarding position and movement of the head in relation to gravity. This system influences balance, muscle tone, bilateral coordination, ocular movements, levels of arousal, speech and language development, and the acquisition of higher level gross and fine motor skills.
- A child with an oversensitive system may avoid movement activities and be cautious/slow-moving
- A child with an underresponsive system may crave movement, seem to be in constant motion, have poor balance, and bump into things.
- Proprioception: Input to the propriceptive system comes through our muscles and joints. This input allows us to determine where each part of our body is in space, how fast it is moving, the direction in which it is moving, and the force of motion.
- A child with poor proprioception may have trouble performing coordinated movements, grading movements/muscle use, and may seek extra proprioceptive input by leaning/bumping/crashing into things.
- Tactile: Input to the tactile system comes through receptors in the skin.
- Over-Responsiveness (Tactile Defensiveness): Over-sensitive to pain, textures, and unexpected touch (standing near others is difficult)
- Under-Responsiveness: seem unaware of personal space, overstuff mouth with food, all food tastes about the same, unaware of runny nose/messy hands/messy face.
- Vision: Input to the visual system comes through the eyes. Some people are over-responsive to visual stimuli. This can make it very difficult to function to one’s full potential when in a busy environment. People with visual over-sensitivity can also be bothered by sunlight or fluorescent lights.
- Auditory: Input to the auditory system comes through the ears. Difficulty processing auditory information may lead to difficulties with sound discrimination, phonemic awareness, articulation (can’t create sounds you can’t hear), auditory attention, auditory memory, auditory sequencing, selective listening, understanding speech in the presence of background noise, understanding muffled speech, and an over-sensitivity to certain sounds.
- Gustatory (taste): Input through taste buds on tongue. Many children crave or avoid certain foods. Many of these preferences are driven by the texture of the food more than the taste.
- Olfactory (smell): Input through the nose. Olfactory input is strongly linked to emotions and memory centers of the brain.
Steps of Sensory Processing
Individuals with Sensory Processing Disorder may have a breakdown at one or more of these steps.
- Reception: sensory organs (eyes, ears, nose, etc.) are functioning
- Detection: message getting from sensory organs to brain accurately and efficiently
- Integration: bringing together all sensory input in order to understand one’s environment and one’s place in it.
- Discrimination: Perception of intensity, duration, and location of sensory input
- Modulation: The brain/body’s regulation of the intensity of sensory input (e.g., ear muscles tightening to block loud sounds; brain enhancing volume of target voice and decrasing volume of extraneous noises)
- Postural Responses: The automatic use of sensory information to maintain posture
- Praxis: Conceptualization, organization, and execution of coordinated movements
At Porter Academy
We have one occupational therapist and an occupational therapy assistant on staff who work with every student within a group setting. The occupational therapists provide training to, and work closely with, the teachers to enable them to incorporate therapeutic activities into the classrooms. We utilize sensory diet activities to provide every student the input they need to optimize learning readiness. Our sensory diets incorporate activities from programs such as The Astronaut Program, S’cool Moves, and Diana Henry’s Sensory Tool Kit. Our teachers are trained to identify sensory needs and meet those needs as they arise in the classroom. Integrated Listening Systems, offered as a supplemental program, has demonstrated improvements in sensory processing.
Sensory Processing Resources
- Ayres, A. Jean (2005). Sensory Integration and the Child: 25th Anniversary Edition.
- Miller, Lucy Jane, Ph.D., & Fuller, Doris A. (2007). Sensational Kids: Hope and Help for Children with Sensory Processing Disorder.
- Dunn, Winnie (2008). Living Sensationally: Understanding Your Senses.
- Kranowitz, Carol & Miller, Lucy Jane (2006). The Out-of-Sync Child: Recognizing and Coping with Sensory Processing Disorder.
- Kranowitz, Carol (2006). The Out-of-Sync Child Has Fun, Revised Edition: Activities for Kids with Sensory Processing Disorder.
- Kranowitz, Carol & Newman, Joye (2010). Growing an In-Sync Child: Simple, Fun Activities to Help Every Child Develop, Learn, and Grow.
- Kranowitz, Carol (2010). The Goodenoughs Get in Sync: 5 Family Members Overcome their Special Sensory Issues.
- Kranowitz, Carol (1995). 101 Activities for Kids in Tight Spaces: At the Doctor’s Office, on Car, Train, and Plane Trips, Home Sick in Bed…
- Isbell, Christy, & Isbell, Rebecca (2007). Sensory Integration: A Guide for Preschool Teachers.