Sensory System Series: The Tactile System
As you sit here reading this blog, what do you feel? You may feel the clothing on your skin, the computer mouse or phone on your fingertips, and the surface you are sitting on. This would be your tactile system coming into play. The tactile system is our sense of touch. We receive tactile information through the receptors in our skin located from head to toe. Light touch, deep pressure, stretching of the skin, vibration, movement, temperature, and pain all activate our touch receptors. The information helps us explore our environment and discriminate properties of items we touch, such as texture, size, shape, and weight.
Our fingertips have 3,000+ touch receptors.
Our tactile system is always activated as our skin is constantly touching something outside our body. It is the first system to develop in utero and plays an important role in learning about our environment and functioning everyday. Think about skin to skin contact for a baby and parent to facilitate bonding. There are therapeutic benefits provided through our tactile system. Tactile information promotes body awareness, motor planning, visual discrimination, language, academic learning, emotional security, and social skills. It is a fundamental system that can impact children’s life.
There are two components of the tactile system: a defensive mechanism and a discriminatory mechanism. The first, defensive, alters us of potential dangerous or safe stimuli. This most often is light touch to the skin where we have hair. The light touch activates the tactile receptors to inform our brain and generate a response. We may quickly react to a harmful stimuli, such as a prick from a needle or our skin getting pinch, or we may respond positively to the touch of a loved one. After we have received a certain touch stimulus multiple times, our body becomes less responsive to it called habituation. We may feel the texture of our clothing once we put it on, but then our body comes used to it. However, for children with sensory processing disorder, they may be highly sensitive to light touch called tactile defensiveness (overresponsive). They react negatively or emotionally to unexpected light touch. Their brain processes it as uncomfortable and terrifying and they may respond with a fight, flight, fright, or freeze response. This may look like them wearing their shirt inside out due to the tag bothering them, yelling at anyone coming close to them as they anticipate their touch, or wiggling in their seat. It can be hard for their system to habituate tactile input.
The second component, discriminatory, helps us distinguish the kind of touch we feel, such as texture of clothing, warmth of a coffee much, or the roughness of our socks. The properties of the item we are touching help us learn about our environment. We develop the capacity to remember the properties of items within our environment and develop tactile discrimination. Tactile discrimination is the ability to distinguish items/objects based on our sense of touch. When you stick you hand inside your purse or pocket to grab you keys, you are able to feel around and pick them out because of tactile discrimination you have learned through the years. The tactile receptors for this component are mainly found in our fingertips, hands, feet, mouth and tongue. They are activated from deep pressure.
As mentioned above, a child’s tactile system may be over-responsive (hypersensitive) where it takes little tactile input to produce a sensation. On the other hand, a child’s tactile system may be under-responsive where the child has low arousal where they don’t notice the sensory input and it takes a lot of input to produce a sensation. They may seek intensive sensory input or may not notice tactile input that usually produces a greater sensation in another child.
Therapeutic Tool Highlight: Theraputty
Theraputty is similar to play-dough, although provides various resistance to promotes hand strengthening, fine motor skills, and stress reduction. Children can squeeze, pinch, stretch, or twist it. Small beads and objects can be hidden within the putty to enhance prolonged engagement.
Sensory bins and tables with various objects are great for tactile exploration and play! Various objects can be used to learn different properties for tactile discrimination and provide opportunites for a child’s nervous system especially those with tactile defensiveness to process the input adaptively. Check out our past blog: Sensory Bin 101.
The above signs and symptoms are only a few ways over-under responsivity to tactile information may manifest. Further, they may or may not help your child depending on their tactile system. Let us know if you have concerns or need more information. We are here to support you!
Check out our sensory system handouts you can purchase individually or as a bundle on our website! A great resource to learn about sensory processing disorder and each of our sensory systems. BONUS: print them off and hang them on the wall for all who pass by to view and learn or share with family, friends or teachers for them to have insight into your child’s sensory system.