This program deals with electroencephalography, recording impulses from the brain. Dr. Walker explains the parts of the brain and a diagram of nerve cells discharging impulses. Lights on a model of a human head indicate brain activity under differing conditions. Dr. Marshall demonstrates how eighteen electrodes are attached to the scalp to record brain waves during an EEG (electroencephalogram) and notes that this is simply a diagnostic tool. He explains the EEG machine and shows the graph produced by the output of its amplifiers. Dr. Marshall then explains what constitutes a normal brain wave based on comparing the voltage and rhythm of a large sampling of medically normal people. Dr. Walker compares several EEG records with differing patterns, and Dr. Marshall explains the significance of the differences, including one lengthy EEG from a patient having an epileptic seizure.