The Man Who Lost His Sense Of Touch

The Mysterious Case of Ian Waterman

In 1971, Ian Waterman suddenly collapsed due to a severe case of what appeared to be gastric flu. Although his illness subsided after a few days, a peculiar set of symptoms persisted. Despite his muscles and joints remaining healthy, Waterman found himself unable to move or feel anything from the neck down. Eventually, he was diagnosed with a rare and extreme form of deafferentation, a neurological condition where certain signals from the nervous system are interrupted or impaired.

Overcoming Deafferentation

Without his body’s constant feedback on how his limbs were moving, Waterman was unable to perform basic actions such as sitting up, standing, or walking. However, over time, he taught himself to use sight to judge the distance of his limbs from other objects. Eventually, he regained complete control of his body, as long as he could see it.

The Importance of Touch in Movement

We often overlook the importance of touch in movement. However, touch is just one part of the somatosensory system, a network that oversees all the sensations arising from the surface and interior of our bodies. This system regulates touch, pain, temperature, and our awareness of our bodies in space, also known as proprioception. When something goes wrong with this system, the effects can be dramatic.

The Role of Receptor Cells

All these sensations are processed by millions of tiny receptor cells embedded in our skin, muscles, tendons, and organs. Every square centimeter of our skin is packed with hundreds of these cells, and their shape, size, and depth determine what kind of stimuli they respond to. Mechanoreceptors sense mechanical deformation of the skin, thermoreceptors respond to temperature changes, nociceptors sense pain, and proprioceptors sit deep in your muscles and tendons, continually detecting and relaying information about the position of your body.

How the Brain Processes Sensory Information

Your brain combines this information with other sensory data to move through space without needing to see your limbs. All of these receptors work by sending electrical signals to the brain through the fibers they’re attached to. The speed of those signals varies with the fiber’s thickness. For example, some nociceptors are attached to fibers with slightly more conductive, fatty myelin than others. So when you get hurt, the electrical impulses from thicker nociceptors trigger sharp, intense pain, while thin, unmyelinated nociceptors are responsible for the dull, aching pain that follows.

The Impact of Disruption in the Somatosensory System

If this process is disrupted—either by damage to the skin, the nerves, or the brain—the network breaks down. Since it underpins so many bodily functions, damage to the somatosensory system can manifest in a wide variety of ways. In Waterman’s case, an autoimmune reaction attacked a large swath of his nervous system, leaving him with no tactile or proprioceptive sensations from the neck down. However, deafferentation is just one of many somatosensory disorders.

The Consequences of Losing Sensations

Individuals can receive damage to a specific brain area or a section of skin, resulting in the loss of certain sensations in particular locations. The impact of this loss can be significant. Losing tactile sensations makes it difficult to gauge how much strength to use in a situation. Without the warning signals provided by thermal and pain stimuli, we don’t react when our bodies are damaged. Moreover, being deprived of social touch can cause a condition known as touch starvation, characterized by anxiety, depression, high blood pressure, and even a weakened immune system.

The Vital Role of Invisible Sensations

Many individuals who face these realities have found innovative ways to adapt. However, it’s undeniable that all these invisible sensations play a vital role in how we navigate the world—even if they can be difficult to put your finger on.