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. This sense allows us to do things with our body without watching our every move. We can button our shirt, walk up and down stairs, tie our shoes, type, put on our clothes, dribble a soccer ball or basketball, all without looking because of our 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.
Together the proprioceptive and vestibular systems provide information about the direction, duration, speed and intensity of which we generate force and movement. When working efficiently they provide us with a grounded feeling in the world supporting attention and regulation to engage with others and successfully participate in daily tasks. They are foundational to most gross motor skills and social skills.
I’d like to make a note regarding the tactile (touch) system. This system provides us with information about the affordances of objects in the environment on which we act upon. It helps us to understand how we fit our body onto (holding a key versus a marker) and into (squeezing into a tight pair of pants versus squeezing into blankets in our bed) objects in our daily lives. It allows us to make critical adjustments to support success and participation with tasks and interactions. It is the foundation to most fine motor skills and social skills.
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: Individuals 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, rides and playgrounds. Individuals with Sensory Over Responsivity often experience anxiety and a general heightened awareness of their surroundings. They can often enter a state of fight (hitting, pushing, yelling, “bossing”) or flight (walking away, hiding, ignoring) when certain sensations are present in the environment or when they are not. For a more detailed explanation visit “Why sensory meltdowns happen in the absence of sensory stimulation.”
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. These individuals can be labeled as “slow learners” or “lazy”. They often have a resting flat affect and seem withdrawn or depressed. They can have difficulty keeping up with daily routines as they always seem one step behind. Parents often report that they have to repeat themselves several times before their under responsive child responds to them and when they do they seem to have not heard the initial bids for attention. Due to the slowness to respond and initiate and lack of awareness of cues in their environment, these kids are often seen as inattentive or having problems paying attention.
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. These children can seem as if they need input, however, when they are provided with input it does not calm and organize them. In fact it is quite the opposite, when the receive additional sensory input they move, touch, smell, or taste even more. Still other children can appear to fall within this category as they seek input, however, the foundational weakness may actually be one of the other categories in this list. For example, a child may be in constant motion because it is hard for them to stabilize their body secondary to Postural Disorder. Still yet another child may be in constant motion because it is hard for him to organize a logical sequence of steps secondary to Dyspraxia. A reliable diagnosis by a sensory trained Occupational Therapist is critical in order to receive the most appropriate and effective treatment.
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.). Children with Sensory Discrimination Disorder often do things in inefficient ways – choosing objects that do not match the task, moving their bodies too fast or too slow, using too much or too little force, placing their body in positions that do not match the task. These individuals are often confused and embarrassed when their strategies for task engagement and interaction do not work.
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. Children and individuals with Postural Disorder seem weaker than others their age, fatigue and tire easily, seem floppy or as if they collapse against gravity. Activities are often more effortful than they are for others. These individuals can feel defeated and fearful as they feel then cannot stand up for themselves and exert control on their world.
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. These individuals can appear clumsy and uncoordinated. They can take a long time to figure things out and may talk themselves through ‘simple’ tasks. 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.
