The Tactile System

The Tactile System

The tactile system gives us our sense of touch. Receptors are located in the skin and allow this sensory system to perceive sensations of pressure, movement, temperature and pain. Sensitivity to touch is greatest in the mouth, lips, tongue, fingers and hands.

Tactile discrimination is the ability to distinguish between characteristics of an item. Without using vision we can identify what we are holding by the size, shape, weight and texture of an object. This is very important when using hands to manipulate small objects.

Localization of touch is the ability to identify where, the amount of force used, and the number of times you were touched. This also contributes to the development of a body schema.

Receptors in the skin alert us to possible danger such as temperature, cutting, crushing, and piercing injuries and pain. If the pain is intense, a reflex response takes place. Tactile information is carried by both large and small nerve fibers. The small fibers carry the pain information to the brain. The large fibers act to block or modify neurons within the spinal cord that cause pain. Applying deep pressure or rubbing a painful area decreases the pain.

A normally functioning tactile system is able to filter out or inhibit a large amount of tactile information. The feel of fabrics or the pressure of a waistband is largely ignored once we are dressed.

Tactile System Problems:

Tactile Defensiveness – (Tactile Hypersensitivity) Touch is perceived as irritating and/or painful. Tactile sensations sent through the large nerve fibers, which are supposed to block painful stimuli from small nerve fibers, are not working. Touch often triggers the fight-or-flight reaction. Tactile input does not habituate with time; rather, the negative reaction may accumulate bothering the child more as the day progresses. These children may do OK at school, but fall apart as soon as they get home.

Tactile Hyposensitivity – The neurological system does not receive or correctly process tactile information. Children may not feel or notice touch unless it is very firm or intense. Even though they may not respond to touch, some children use touch to explore the environment.

How the Tactile Sense Affects Everyday Skills

In addition to helping us to protect ourselves and to discriminate among objects, the tactile sense gives us information that is necessary for many kinds of everyday skills:

· Tactile Perception

· Body Awareness (Body Perception)

· Motor Planning

· Visual Perception

· Academic Learning

· Emotional Security

· Social Skills

Characteristics of Tactile Dysfunction

Tactile Defensiveness: (Tactile Hypersensitivity)

· Reacts negatively and emotionally to light touch, may withdraw, rub or scratch the place that has been touched. May hit if touched unexpectedly.

· Avoids or reacts negatively to possibility of light touch, such as circle time or standing in line.

· Picky with choice of clothing – may prefer loose-fitting cotton clothes. Dislikes tags, stiff new clothes, turtlenecks, elastic bands at ankles and wrists, hats, mittens and scarves.

· May prefer only long sleeves and pants or only shorts and short sleeves and may have difficulty transitioning clothing between seasons.

· May fuss about sock seams.

· Difficulty switching to new shoes or not like going barefoot.

· Hates having dirty hands or body, but hates having face washed by another.

· Dislikes baths, hair washing, fingernail trimming and hair cuts.

· Avoids walking barefoot on the grass, sand or wading in the water.

· Toe walks when barefoot.

· Picky eater – textures, tastes and temperatures.

· May have a toy in hands frequently to protect self from other tactile input.

Tactile Hyposensitivity:

· Tactile seeking – touches everything, enjoys strong tactile input, such as messy textures, bumpy or rough surfaces, vibration and deep pressure.

· Mouths objects beyond an appropriate age.

· May be unaware of touch unless very intense – may be unaware of food on face or runny nose.

· Poor body awareness and body schema – unable to identify body parts or perform certain motor tasks without looking (buttoning, zipping, writing letters and numbers).

· Appears clumsy and awkward.

· Leaves clothes twisted on body or shoes untied.

· Has trouble perceiving characteristics of objects, such as shape, size, texture and temperature, without visual cues.

· Poor fine motor skills for tool use, such as coloring, writing and cutting.