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Human Senses TV Programmes

Programme 4 - Touch

Humans are very sensitive to touch, but different parts of our body have different sensitivities. Nigel demonstrates that when it comes to our sense of touch, humans are similar to elephants.

The skin on our fingertips is some of the most touch-sensitive skin on our body

We have a few areas where we are extremely sensitive, just like the elephant's trunk. The rest of our body is surprisingly insensitive, like the elephant's thick hide. The different density of touch sensors in the skin in different parts of the body explains why some parts of the body seem to have a much lower pain threshold. A microscopic splinter in a finger can be extremely painful, while a cut on your leg may not hurt as much.

Ultimately, pain involves much more than what's happening with the touch sensors in the skin. It has a lot to do with what's going on in the brain. At University College London, Professor Tony Dickenson has devised an experiment using mild electric shocks, which reveals how much more painful something will feel if you believe it is going to hurt – and how painless it is, if you think you've taken a painkiller.

Our minds can sometimes block out even the most excruciating pain. Nigel visits Dr David Spiegel at Stanford University, who uses hypnosis to help combat severe pain that can’t be tackled with drugs. Under hypnosis, Nigel has pins stuck in his hand and feels almost nothing. In Hawaii, circus performer Jim Rose has prepared a bed of blades for Nigel to lie down on. Jim prepares to smash a breeze block on Nigel's chest - will it really be as painless as he hopes?