Crash Course on Sensory Processing: Part Two

Written by: Nicole Corriveau, M.S., OTR/L

Occupational Therapist


In the blog post Crash Course on Sensory Processing: Part One, I discussed the different sensory systems and red flags that can be observed within each. Next, I will dive into Sensory Processing Disorder and the different categories that fall within this disorder.

Sensory Processing Disorder

Sensory processing encompasses the way our bodies receive messages and how we turn those messages into responses, such as a motor action or emotional display. We receive sensory input constantly throughout the day, and if we’re lucky, our brains are able to process this input in an organized, efficient manner and produce reactions that are functional and typical. With sensory processing disorder, a person’s brain does not process particular sensory input in an organized way, which can lead to major disruptions in everyday life. Furthermore, the brain may be able to organize sensory information in certain environments and at certain times of the day, but may struggle more in particular environments or in the morning versus evening, for example. Lucy Jane Miller, Ph.D., OTR is the founder of the first comprehensive Sensory Processing Disorder research nationwide and wrote the book Sensational Kids: Hope and Help for Children with Sensory Processing Disorder (SPD). The following categories are gathered from this book (which I highly recommend for everyone to read):

Sensory Modulation Disorder

This disorder is characterized by a chronic and significant challenge with processing sensory information and producing behaviors that match the intensity and context of the sensory input. It is broken down into three subtypes:

Sensory Over-Responsivity

This is also sometimes called “sensory defensiveness”. A child with sensory over-responsiveness processes sensory input more quickly, intensely, and/or for longer periods of time than is expected. This over-responsivity can occur within one, two, or more sensory systems, dependent on the child. These children regularly feel as though the world is “too much” for them and can react with tantrums, withdrawing, crying, and/or avoiding. These children may be particularly irritable, fussy, unsociable, excessively worried/cautious, and become very upset with changes to their routine. The following are some red flags that can be observed in an over-responsive child:

  • Bothered by various tactile input, such as clothing, messy hands (from food, crafts, outdoor play, etc.), or fuzzy/furry textures
  • Strongly dislikes grooming tasks (i.e., cutting nails, washing hair, brushing teeth, etc.)
  • Easily distracted by background noise
  • Frightened by loud noises (i.e., fire alarm, large crowds, vacuum cleaner, blender, lawn mower, etc.)
  • Fearful to play on playground equipment or dislikes being upside down 
  • Dislikes bright lights/sunshine

Sensory Under-Responsivity

Contrary to over-responsivity, children who are under-responsive exhibit less of a reaction to sensory input, requiring more input, or input for a longer period of time, to register a motor and/or emotional response. These children may present as more withdrawn, quiet, and to themselves. They may be labeled as a “good baby” when they’re younger as they are often quiet and content without needing much attention. These children often fly under the radar for a long period of time. The following are some red flags for under-responsivity:

  • Appears to have a high pain tolerance; doesn’t cry or appear upset when injured
  • Prefers sedentary play, rarely initiating motor and/or novel activities
  • Slow and unmotivated to be independent with activities of daily living, i.e., feeding self, dressing self, potty training, etc.
  • Doesn’t respond to sounds around them or hear their own name being called
  • Lack of awareness of bodily sensations, including being hungry, hot/cold, and/or needing to use the toilet
  • Does not appear bothered by messy hands or face

Sensory Seeking

These children seem to constantly seek movement, sensory experiences, and sensation, often in an unsafe or socially inappropriate way. Sensory seekers are often labeled as “misbehaved” or “bad” due to their constant seeking of input. They often struggle with appropriate social interactions, touching people without permission, knocking kids over, or completely overwhelming the children around them. These children may become angry or aggressive if they’re forced to stop moving. They can appear demanding, intense, and difficult to calm down. Many children exhibit some level of sensory seeking at times, but sensory seekers consistently crave more intense input and for longer periods of time. The following are red flags for a child with sensory seeking challenges:

  • Constantly on the move, including unsafe behaviors
  • Enjoys crashing, bumping, jumping, falling, rough-housing, etc.
  • Does not appear to get dizzy when spinning; could spin forever
  • Constantly touching objects or people, to the point of annoyance
  • Talks non-stop; exhibits challenges with taking turns in conversation
  • Can be visually fixated on objects
  • Prefers strong tastes and smells (bitter, sour, spicy)
  • “Mouths” objects beyond age-expected norms
  • Cannot sit still during activities where being seated is expected; unable to stay seated in a chair

In the last and final installment of Crash Course on Sensory Processing: Part Three, I will provide information about Sensory-Based Motor Disorders. If you have concerns with your own child’s sensory processing challenges, you can reach out to us at (248) 885-8240 to set up an occupational therapy evaluation! You can also like us on Facebook and follow us on Instagram!