Pain practical and Richard Dawkins

We had a practical on pain this morning. The demonstrators had a laser which can stimulate different pain nerve fibres selectively when they zap you with it, so one zap can make you feel slow burning pain whilst another gives a sharp pin-prick sensation. It was good fun and we learned that (in my group at least) boys are wimpier than girls! We also put capsaicin (chilli pepper cream) on our arms to see how the burning effect sensitises the skin to pin pricks. Unfortunately, it has no effect on some people and I couldn't feel any burning or sensitisation at all. In another experiment we put our hands onto a grill with alternate warm and cold bars, and the combined effect gave a feeling of intense heat. There was also a machine that vibrates and touching the back of the ankles with it makes you fall backwards, but touching the back of the neck makes you fall forwards (because of interactions between proprioceptive and other sensory neurons). I've even been recruited by the neurologist teaching us to be a volunteer for one of her experiments.

I've just got back from seeing Richard Dawkins speak at the Union. He read out some of his new book with his wife (who's apparently an actress) and then answered questions. It was a good evening off working and I now know a lot more about barnacles and platapi than I did a couple of hours ago!