Many people will encounter difficulties in sensing the world around them. However, some individuals will have particularly difficult experiences relating to their senses. Because of this, they may be considered an individual with a sensory processing disorder.
Sensory processing disorders are conditions that affect different aspects of a person’s senses: sight, hearing, smell, taste, touch, as well as the internal senses of proprioception (body awareness) and vestibular sensing (movement and balance).
Examples of sensory processing disorders include:
Incontinence due to a less sensitive sense of proprioception
Being overwhelmed by flashing lights and loud noises
Different subtypes - Sensory Modulation Disorder
Sensory modulation disorder entails difficulty regulating and responding to sensory input. Three common subtypes include:
This means that certain senses may be more sensitive to sensory input that are generally regarded tolerable.
An example of this would be being overwhelmed by lights/sounds.
An individual with this might have reactions such as intolerance of sensory triggers or something long term, such as picky eating.
This means that certain senses may be less sensitive to sensory input that most people would notice.
An example of this would be an inability to process/detect weaker sounds/smells/tastes.
May result in an individual not noticing their surroundings.
This is similar to sensory under-responsivity in the sense that certain senses may be less sensitive to sensory input that most people would notice.
Difference is in reaction - an example of a reaction to the lack of sensory input might include playing audio/speaking louder than “tolerable”.
Different subtypes - Sensory Based Motor Disorder
Sensory based motor disorder involves difficulty with movement and/or balance, due to incoordination between sensory input and motor responses. Two common subtypes are:
This means that one would have difficulty planning, sequencing and/or executing certain actions. For example, simple things such as writing a sentence.
Examples include difficulty with scissors or utensils, putting on clothes, messy handwriting or poor hand-eye coordination.
This means that one would have difficulty controlling muscles leading to physical instability
Examples include drooling, poor balance or poor posture.
Different subtypes - Sensory Discrimination Disorder
Sensory discrimination disorder involves difficulty perceiving differences between different sensory inputs for a certain sense (may be one or more).
Examples include not being able to differentiate between letters, smells, tastes, or textures, or being unaware of physical touch
Relation to Other Conditions
Sensory processing disorders are often associated with ASD, ADHD and Misophonia:
SPD or signs of SPD occur more often in people with Autism Spectrum Disorders
Many autistics face issues with sensory processing - some may be more responsive to certain sensory stimuli, some may be less sensitive to sensory stimuli (like SMD - sensory over-responsivity/sensory under-responsivity)
On the other hand, many people with SPD do not have ASD; the following diagram shows the overlap between SPD and ASD:
Signs of SPD are also present in people with Attention-Deficit Hyperactivity Disorder (ADHD)
Overlapping symptoms may include hyperactivity, constant need for sensory stimulation, and losing interest/focus if understimulated (like SMD - sensory craving)
However, these two disorders are classified as unique disorders
SPD and Misophonia share quite an amount of overlap
Misophonia involves an intense reaction to patterned sounds, such as chewing and pencil tapping, and sometimes the visual stimuli that come with them, such as seeing someone chew
Both SMD - sensory over-responsivity and misophonia trigger a “fight-or-flight” response, fear, anxiety, anger and/or disgust
However, not much is known about misophonia at the moment