Bob’s your homunculus.

All body parts are not created equal, as far as the sensory cortex of our brain is concerned. It turns out that certain parts have a much higher level of neural processing power devoted to them.

Here’s a translation of the body’s sensory map, called a homunculus by neuro-science:

Sensory Homunculus

Just goes to show – not all the important stuff happens in the in the sensory cortex, eh?