To find this out you will need a friend to work with, a washable felt pen and a fine bristle from an old hairbrush.

The palm of your hand and the sole of your foot are good areas to test.

Mark a regular pattern of 20 small dots (e.g. in a square) on the test area. The person being tested must not look.

Gently touch each dot in turn with the bristle and note whether or not the person can feel it. Then do the same for the other body area.