The tactile system

The epidermis is the skin’s outer layer. It provides a protective barrier for the dermis. The dermis is a thick layer of tissue below the epidermis that forms the “true skin”. It contains blood, capillaries, nerves, sweat glands, and hair follicles. It’s also where all of the different tactile receptors are located.

  • Meissner’s Corpuscle – These sensory receptors are located nearest to the skin’s surface. When these corpuscles are deformed by pressure, they send neural signals to the brain. These receptors perceive fine touch, pressure, and vibrations.

  • Merkel’s Disk – These receptors are nerve endings located at the bottom of the epidermis and in hair follicles. They send signals to the brain that decode the features of touched objects such as their texture and temperature. They are extremely sensitive to pain.

  • Ruffini Ending – These receptors perceive any kind of stretching of the skin. They also detect temperature and pressure.

  • Pacinian Corpuscle – Detects deep pressure sensations. These receptors play a large role in proprioception.

  • Krause End Bulb – These are sensitive to the cold. In fact, they only activate when touching something with a temperature below 20 degrees.

  • Free Never Endings – are non-specialized nerve cell endings. They respond to all stimuli – pressure, temperature, pain, texture, etc.

For Discrimination and Perception Issues

  • Mix small toys in sensory bins filled with sand, flour, rice, or water beads and encourage your child to feel around to find them.

  • Play guessing games where your child closes their eyes and tries to guess what object you give them based on how it feels.

  • Draw shapes or letters with your finger on your child’s back and get them to guess what you drew.

  • Touch matching games – like playing memory but with different textures instead of photos

  • Mystery Objects – Take 5 or 6 pairs of matching objects and put them in a bag. Have your child pull out one object, and then reach in the bag to find it’s pair relying on sight only.

underresponsive

Under-responsive means that they do not notice and process information received from the senses as well. They often seek extra sensory input or they might need support from others to register sensory input.

  • Constantly touches everything, as if they can’t resist.

  • Enjoys certain strong flavors – salty, sweet, sour, etc.

  • High pain tolerance, doesn’t notice when they get hurt

  • Rough with others, may hurt them without meaning to. Others may say they are “unaware of their own strength”.

  • Doesn’t notice when touched lightly by others

  • Not aware when their face is dirty or nose is running

  • May engage in self-injurious behavior such as biting, pinching, hitting, or headbanging

  • May not notice or seem affected by the temperature. For example, could go outside without a jacket and not complain of the cold. Likewise, may wear long-sleeves in the summer and not complain about the heat.

Overresponsive

Tactile defensiveness is a term used by occupational therapists to describe hypersensitivity to touch. Tactile defensiveness may look like the following :

  • Becomes dysregulated, upset, or anxious with light and unexpected touch

  • Is bothered by certain textures of clothing, or the tag on clothing

  • Experiences difficulties walking barefoot on certain textures, like sand, grass, or carpet

  • Exhibits dysregulation when engaging in “messy play” and may demonstrate a need to always keep hands clean

  • Demonstrates difficulties with wet tactile mediums, such as soap, lotion, shampoo, etc.

For example, as someone with “typical” sensory integration, they may not enjoy having the tag of their t-shirt rubbing against their neck, but they will still be able to carry on with their day, eventually forgetting about the tag. For someone who is tactile defensive, their day may be impacted by the tag, likely limiting their ability to participate in daily tasks. Potentially this could result in an all-out meltdown until the sensory stimulus (the tag) is removed. Even once removed, they may require additional recovery time.

  • Fearful or strong dislike of large crowds.

  • Dislikes hair brushing, washing, drying, and cutting

  • Extremely ticklish 

  • Walks on tiptoes

  • Refuses to walk in bare feet

  • Responds with emotional intensity to light touch. For example, acting as if a gentle pat on the back is painful.

  • Completely avoids certain sensations – like putting feet in the sand, or touching finger paint.

  • Upset by the feelings of tags or seams in clothing. May even refuse to wear certain clothing items of types of fabric. 

  • Picky Eater.

  • Doesn’t enjoy messy play – sand, mud, slime, foam, etc.

  • Acts distressed when getting fingernails and toenails cut.

  • Finds cold or warm weather extremely uncomfortable