1. Electroencephalograph - EEG Brain has continuous electrical activity that can be recorded Pairs of electrodes attached to scalp form distinct channels Weak signal ~millivolts is sent thru amplifier Continuous output recorded via galvanometer.

2. Each pair of electrodes forms a channel to measure something - maybe potential difference between them? Localized anomalies pinpoint physical brain problems Computer waveform analysis: high-speed samples taken 200 times/second to convert analog>digital Commercially available to run on PCs and Macs, you can even use it qualitatively if you’re bad at math