Let’s start with an overview of our senses. You are likely familiar with the common ones – sight, sound, taste, smell, touch/tactile. These do not need much more of an introduction. But there are two others that are not too familiar – proprioception and vestibular – which need some definition before we move forward.
Proprioception is an internal sense that comes from receptors in our muscles and joints. This sense gives us information about where our body parts are “in space” and general body awareness. When you close your eyes and put one arm up straight in the air and the other arm behind your back, you know where your arms are without looking at them because of your proprioceptive sense.
Vestibular input comes from our inner ear. It keeps our head upright and perpendicular to the horizon and is imperative to balance. If you move your body forward and backward and side-to-side in large swaying motions you will notice that your head automatically remains upright without you having to try to keep it there. This is your vestibular system doing the work for you. This system helps us to understand and navigate our body safely through space.
What do our senses do?
Our senses work together to provide us with information about our body and the environment with the goal of producing movements (adaptive responses) to successfully engage in interactions, tasks and activities in our environment.
So what is Sensory Processing Disorder?
Sensory Processing Disorder (SPD) occurs when sensory signals are not detected or they do not get organized in a way to produce appropriate responses. This occurs in many forms.
Sensory Over Responsivity: Children with Sensory Over Responsivity (SOR) respond more than is expected to sensory input. These children are often defined as sensitive or hypersensitive. They are often startled by sensory experiences or avoid sensory experiences. Some examples are kids who cover their ears to loud sounds, refuse to engage in messy play, are picky dressers or avoid swings and rides.
Sensory Under Responsivity: Children with Sensory Under Responsivity (SUR) respond less than is expected to sensory input. These children are often defined as hyposensitive or “in their own world”. They often bump into things, do not realize they are hurt or respond less than expected to painful experiences, do not respond to their name or seem as if they are not motivated to do much.
Sensory Cravers: Children who are Sensory Cravers tend to seek sensory input when it is not appropriate to do so. They are constantly craving to touch, listen, move, smell or taste.
Sensory Discrimination: Children who have challenges in Sensory Discrimination have difficulty understanding the details of sensory information. They misinterpret the amount of force needed to accomplish tasks, the frequency and rhythm of movement patterns, the differences in sounds and sights (/b/ versus /d/). Discrimination refers to the ability to understand how our body moves in relation to the environment and how our body parts move in relation to each other. It is the understanding of the affordances of the environment (soft, hard, stable, unstable, safe, unsafe, etc.) and the qualities of the experience (wobbly, sturdy, fast, slow, whole body needed, one part of my body needed, etc.).
Postural Disorder: Children who have Postural Disorder struggle with remaining stable during movement and stationary activities. They have poor stability at their core/trunk and frequently have trouble coordinating the use of both sides of their body together in a coordinated fashion.
Dyspraxia: Dyspraxia is often understood as having challenges in motor planning. Children with dyspraxia have difficulty coming up with ideas, formulating goals, developing plans and coordinating and executing movements. For a detailed definition please visit “What is dyspraxia.”
Individuals with Sensory Processing Disorder can be impacted by one or many of the above areas.