Running around and doing what we like is what we associate with free will. What on earth were you thinking about when you did that is a question that we are sometimes faced with afterwards. Mostly, we don't have any idea. It all went with the moment.
Then as we sit like gods on Mount Olympus watching our lab mice or rats run about in our mazes trying to solve problems, we ask the same question: "what are they thinking?" We can make a start on this quest if we know which parts of their tiny minds are flashing electric pulses from neuron to neuron. The conventional solution is to stick electrodes into the brain and wire the beasties up to computers. However, running around and behaving normally must be hard to do with thick heavy cables hanging off your head.
A new solution is now available. A large multinational team have come up with mouse and rat-sized thinking caps (1). The electrodes are still obligatory, but the hats have multi-channel radio transmitters kitted out with re-chargeable batteries. So after a day or so of running around, the mouse or rat is simply plugged into the lab electricity supply for a while and they're all ready to go on the next set of experiments.
The hats are used to follow the brain activity of, to quote the authors, "freely behaving mice and rats." I'm not sure how freely behaving I would be if I was trying to solve problems with a big hat containing a radio transmitter and battery of the same relative size as their mice are wearing. I would be terribly self-conscious and feeling definitely geeky if not a tad exploited. Certainly, my compensation would have to be increased if I were to play ball.