Something electroencephalographic has to do with a scan that measures electrical activity in a person's brain.
When a doctor or scientist wants to get a look at someone's brain waves, they use an electroencephalographic test known as an EEG, short for electroencephalogram. The roots of electroencephalographic are electro-, or "electricity," from a Greek root meaning "amber"; the Latin encephalon, meaning "brain"; and -graph, "instrument used for recording." This adjective is used to describe the process of painlessly scanning a patient's brain to diagnose or treat injuries or neurological conditions.