Written by Tricia Au
Imagine SPD as a giant tree with a lot of branches, these branches represent the subdivisions of SPD. You might be wondering why is this relevant to me? Having the awareness and knowledge of SPD in general is only the tip of the iceberg. The subdivisions of SPD can help guide us in knowing what specific challenge your child is facing so you are better prepared to strategically implement the appropriate support and guidance for your child.
Subdivisions of Sensory Processing Disorder (SPD)
Sensory Modulation Disorder (SMD)
SMD looks into the regulation of sensory information. For example: A child may hold onto a light bulb without responding to the heat immediately, it may take the child a few seconds later to react to the stimulation but by then the child would have been badly burned from the heat of the light bulb. Children who are facing SMD have difficulty converting sensory information into appropriate behaviours that correlates with the nature of the sensory message.
Sensory Over Responding
Sensitive to sensory input
Detects sensation easily and intensely
Child may feel as if they’re constantly being blasted with sensory information through the different senses
It is also known as “sensory defensiveness”
Child may withdraw from having someone touch them or they may close their ears to loud noises
Sensory Under Responsive
Child may require a longer time to respond to sensory messages
Often not aware of what is occurring around him/her, for instance, may not notice when someone touches him/her
Child doesn’t react when seriously hurt and is not fazed by minor injuries
Child often is not aware of his/her body sensations, for instance hunger, hot or cold
Is often touched to gain attention, for instance a tap on the shoulder or spoken loudly to gain attention
Sensory Craving
Child seeks sensory input, may go to the point of an uncontrollable desire
Feels the need to constantly be active. For example, moving, running, jumping, bumping, crashing, etc
Enjoys spinning, rolling, swinging
Likes to touch objects or touches/invade other people’s space
Would taste or smell the object or toy
Sensory-Based Motor Disorder (SBMD)
SBMD refers to the responsiveness of the child based on the sensory information received. There are two subtypes under SBMD, which are Postural Disorder and Dyspraxia.
Postural Disorder
Their core trunk has poor muscle tone, having a strong core trunk helps with stabilizing your shoulders and arms
They get tired very easily and often seems weak
Finds it challenging to balance
Have bad posture because of a weak postural control
Dyspraxia
Finds it challenging to convert sensory information into physical movements
Feels as though the movements are unfamiliar to them especially movements with multiple steps
Have difficulty planning the movements in terms of the sequence of action
Usually seen as clumsy, awkward or accident prone
Prefer sedentary activities which involves little to no physical activities
Sensory Discrimination Disorder (SDD)
SDD emphasizes on the ability to interpret sensory information that comes into the brain. Often times children with SDD requires extra time to understand and respond to the sensory input. They find it challenging to distinguish between the different input of senses (visual, auditory, olfactory, tactile, gustatory, vestibular, proprioceptive, interoceptive) as quickly and naturally as others.
Visual
Through our visual system (eyes), we are able to gather information about our surrounding environment. It helps us determine where we are in space
When combined with our vestibular, proprioceptive and tactile systems, it helps us to make sense of the world as well as perform physical activities. For example, throwing a ball.
Enables us to understand the body language of others
Struggling within the visual system can lead to an individual having difficulties telling things apart. This may elicit feelings of shame, anxiety, etc
Auditory
Processes and interprets information of what is being heard
Enables us to differentiate sounds that are coming from left and ride side of the ear
The cochlea is affiliated closely with the vestibular system, hence the combination of auditory and vestibular system plays an important role in improving one’s language skills
Issues with the auditory system can be really challenging for an individual, especially when the words and pitch they hear could be vastly different
Olfactory
Processes and translates information through the sense of smell
Information processed through the this system can quickly affect the emotion and call up memories of an individual
Not only does smell help us associate food better but it also helps us detect danger. For example, the smell of cookies burning will elicit an immediate reaction of quickly turning off the oven
Tactile
Receives sensory information from our skin
The way information is processed and perceived from the skin plays a big role in behaviour
Sensory receptors in our skin identifies and differentiate texture, pressure, heat, cold and pain according to the information received
Subsystem in touch:
Protective system: reacts to stimulant that may be detected as being dangerous
Discriminative system: discern specific information about the traits of things that we feel. For example, hard and soft, rough and smooth, etc
Gustatory
Provides information on the taste of food and liquid
May not seem important but some individuals with gustatory system issues have feeding problems. Severe feeding problems can lead to the use of a feeding tube.
Vestibular
Refers to the movement of the head in relation to gravity
Proprioceptive
Refers to the ability to feel changes in our muscle and joints
Sends us sensory information when there’s movement in our joints. For example, stretching, straightening, pulling, compressing our joints
Gives us awareness of the position of our body parts
People with poor proprioceptive systems are unable to gauge their strength and often times they have difficulty feeling their muscle and joints
Interoceptive
Refers to the sensations from internal sensory
Provides information about how our bodies feel inside
For instance, the feeling of hunger, thirst, bowel movement, needing to go to the toilet to pee
Reference
(2020). Subtypes of SPD. Retrieved from https://www.spdstar.org/basic/subtypes-of-spd
Lucy, J.M. & Doris, A.F. (2007). Sensational Kids: Hope and Help for Children with Sensory Processing Disorder. TarcherPerigee.
Doreit, B. (2012). No Longer a Secret: Unique Common Sense Strategies for Children with Sensory or Motor Challenges. Future Horizons Incorporated
If you have not read about our posts on the introduction of Sensory Processing Disorder (SPD) , you can click on this link.
You can also check out our related posts on how parents or caregivers can help support and guide children with SPD: