What are the senses?

Tactile System – The tactile system is one of the largest sensory systems. This is the very first sense to form, with development at around 8 weeks of gestation. The largest amount of tactile receptors are found in our mouth, hands and feet. Touch plays an important role in our ability to learn about and interact with the environment around us. We use touch to discriminate textures, temperature, pain, light and deep pressure touch. 

• Over-responsive children may not want to touch objects necessary for completing tasks, flinch when touched, dislike showers, dislike messy play (dirt, water, playdoh), dislike certain clothing or dislike certain textures of foods.
• Under-responsive children may have a loose grip when holding items, not notice when their hands or faces are messy, frequently mouth items, frequently touch children or objects or not notice when being touched.

Proprioceptive System – The proprioceptive sensory system is our body awareness and tells us where our body is in space. The receptors are in our muscles and tendons in our joints. Feedback from this system tells us how much force we are using when manipulating objects. Proprioception can provide a calming effect on our nervous system, helping us to feel better and can increase our productivity by waking us up. 

• Under-responsive children may seek lots of movement such as jumping, throwing their bodies to the ground, banging against walls or other children, or use too much force within their movements such as breaking something when they pick it up or throwing it to the ground. 

Vestibular System – The vestibular system tells us how and where we are moving, by letting us know if our movements are up, down, fast, slow, angular or circular. Our vestibular system also tells us where our head is in space and helps with balance. The vestibular receptors are in our inner ear. This system feeds into our ability to feel awake or feel sleepy, known as our arousal level.

• Over-responsive children may move very slowly in an attempt to avoid vestibular input, dislike roller coasters, get car sick on long journeys, complain of headaches after movement activities or dislike having their feet off the ground (such as swings and slides).
• Under-responsive children may try dare-devil movements to increase the sensation. This can be seen as ‘constantly on the go’, rocking in their chair, shaking their head, or hanging upside down off furniture.

Visual System – When we look at the visual system in regards to sensory information, we are not thinking about whether the child can read a letter on the wall 5 meters away or if a child can see the TV, what we are thinking about is what the child can perceive and whether this makes the child alert or calm. Visual input can have both alerting and calming effects. Variations in light, color and number of visual distractions contribute to attention level. Increasing or decreasing visual input during tasks can help maintain effective arousal levels for learning and doing in the classroom and home settings. 

• Over-responsive children may be quickly distracted by looking out windows, struggle making eye contact, prefer dark environments or lose their place when reading. 
• Under-responsive children may not notice someone new walking into the room, struggle to find their red pen on a table that has lots of paper, pens and stationary on, and may seek out bright, reflective or spinning objects.

Auditory System – When thinking about the auditory system, we usually recommend that children have their hearing tested if there are any concerns, to rule out medical conditions. Auditory feedback is the ability to detect sound waves through the ear canals and this feedback can have an alerting or calming effect.

• Over-responsive children may be able to detect a lot of noise easily and therefore may cover their ears in loud environments, become distracted, disoriented or overwhelmed in noisy environments or dislike the sound of the hand dryer or hoover. 
• Under-responsive children may miss their name being called or seek out humming, loud vocalisations and noisy toys.

Gustatory System – Also known as our ability to taste. We have 5 different taste receptors, salty, sweet, bitter, sour and umami (savoury or meaty), on our tongue, soft palate, and cheek. From the time we are born, we know how to use oral motor input to calm us and to learn about our environment. 

• Over-responsive children may have a very limited diet and dislike many textures and tastes.
• Under-responsive children may dribble, have food fall out their mouths, not notice when food is around their mouth, may put everything in their mouths, eat inedible objects (PICA), and have a very varied diet. 

Olfactory System – Also known as our ability to smell. Olfactory receptors are found in our nose. The olfactory system is one of our most primal sensory systems as it helps us to detect safety e.g. mothers scent and danger e.g smoke from fire. Olfactory input can be highly emotive as it can remind us of memories, both good and bad, as the processing centre for this information in the brain is situated close to our memory centre.

• Over-responsive children may not be able to manage being in a room with particular smells.
• Under-responsive children may seek out smells by sniffing all foods prior to eating them and may smell inedible items or objects frequently.

Interoceptive system- Our interoceptive system refers to our internal bodily cues. We have receptors in the organs inside our bodies that send signals to our brain to tell us when for example: our bladder is full, when our stomach is empty, when we are feeling too hot or if we are thirsty. This system motivates us to take action to meet our internal bodily needs, therefore when our stomach tells us we are hungry, we will get up to seek food.

• Under-responsive children may not register signals from their organs that tell them when they need to urinate or that they are thirsty or other internal processes. These children may look very flushed in the face but do not take their jumpers off, may struggle with toilet training or struggle to fall asleep at night.