Electroencephalography (EEG) is the recording of electricall activity along the scalp produced by the firing of neurons within the brain. In clinical contexts, EEG refers to the recording of the brain's spontaneous electrical activity over a short period of time, usually 20–40 minutes, as recorded from multiple electrodes placed on the scalp.
I hope to be making my own of these devices using the open source EEG project.
Hopefully I won't fry anyones brain trying to make this thing. If it all goes the way of the pear, my back up plan involves measuring skin conductance which is a hell of a lot easier to do then the above. I'll make a post about it soon enough