Sensory processing disorder is a condition wherein the central nervous system receives sensory signals from outside stimuli but does not organize them properly so that the individual can react with an appropriate response.
Because they all live under the same umbrella term, “sensory processing disorder,” the various subtypes of this disorder often become misunderstood. The truth is that many of them are very different from one another. They can be broken down into “sensory modulation disorders,” “sensory-based motor disorders,” and “sensory discrimination disorders.” Each of those are then broken down even further into subgroups that are defined by what area the person struggles in.
The truth is that no one can truly understand or help someone who has a sensory processing disorder until they know which subtype of the disorder is present. Some of these subtypes are almost complete opposites to one another, making it very important to know know the differences.
Below, we outline the three major types of sensory processing disorder and the smaller subtypes that belong to them.
Sensory Modulation Disorders
Sensory modulation disorders refer to how a person reacts to an abundance or absence of sensory stimulation. These disorders include sensory over-responsive, sensory under-responsive, and sensory craving.
A sensory over-responsive individual likely tends to respond to stimuli most people would find tolerable in an odd fashion. They may respond more quickly or for too long a time, or they may have a stronger reaction than expected. Sensory under-responsive individuals, on the other hand, often have more delayed or mild reactions to sensory stimuli than most people would, or they don’t appear to have experienced the stimuli at all, such as when someone calls their name.
Those with sensory cravings often seek out sensory stimulation. However, this stimulation often results in mental disorganization rather than satisfaction, driving the need for more stimulation.
Sensory-Based Motor Disorders
Sensory-based motor disorders have to do with the way the person’s reaction to sensory stimulation affects his or her motor skills. Subtypes in this group include postural disorder and dyspraxia.
Postural disorder often involves the impaired understanding of the body’s position and poor core strength, resulting in weakness, lack of physical endurance, and poor posture.
Dyspraxia describes individuals with an impaired understanding of their body’s position in relation to other objects. People with dyspraxia often have difficulty planning and executing certain movements, usually those that involve fine or gross motor skills or movement patterns that have not been learned or practiced before.
Sensory Discrimination Disorders
There are eight types of sensory discrimination disorders, all related to the senses. Auditory discrimination disorder causes people to have difficulty interpreting what is heard. Visual discrimination disorder, sometimes known as dyslexia, makes it hard to interpret what is seen. Tactile discrimination disorder means difficulty understanding sensory stimuli experienced through touch. In a similar vein, gustatory and olfactory discrimination disorders refer to issues with interpreting stimuli that is tasted or smelled, respectively. These issues with interpretation of sensory stimuli often result in socially inappropriate responses to the stimuli, which can cause communication issues with others, learning difficulties, and sometimes even safety hazards.
But there are more than just the 5 senses we generally talk about. Other types of sensory discrimination disorders deal with our senses of movement, balance, and the health of our bodies.
Vestibular discrimination disorder describes people who struggle to interpret the feeling of movement and the positioning of their bodies. There is also proprioceptive discrimination disorder, which involves difficulty with the use of muscles and joints and the sensory stimulation that provides. Lastly, interception discrimination disorder refers to issues with interpreting messages from the internal organs, such as knowing when to urinate.
All of these disorders may be referred to as “sensory processing disorder,” but they are really very different conditions, and the individuals who have them often behave very differently from one another, need different things, and respond differently to the same stimuli. One thing they all have in common, however, is that they may require neurotypical people to be a bit more understanding in certain situations.
The more you know, the better you can understand and help someone with a sensory processing disorder as they work on adapting to daily life and interacting well with others. And if you have a sensory processing disorder yourself, properly understanding the disorder can help you learn to communicate with others better about your preferences and needs. A little knowledge and understanding could go a long way toward making the world a better place!
Elizabeth Nelson is a wordsmith, an alumna of Aquinas College in Grand Rapids, a four-leaf-clover finder, and a grammar connoisseur. She has lived in west Michigan since age four but loves to travel to new (and old) places. In her free time, she. . . wait, what’s free time?