Ever wondered what happened to your brain when you tap your finger?
See this movie:
In the above movie I used topo software (by Hitachi) to visualize the blood flow changes in the brain. The data was collected by Hitachi ETG 4000 and the subject was myself. I was doing a finger tapping task. The probe position was measure by 3D digitizer. You can see that during finger tapping (right hand) the blood flow in the left motor cortex increased.
The movie itself is made using http://www.screencast-o-matic.com/