Real world article
(written from a production point of view)
In the script of the Star Trek: The Original Series first season episode "The Squire of Gothos", an encephalograph is a device used for scanning a humanoid's brain.
When Spock noticeably began to detect an unusual reading on the USS Enterprise's bridge (later identified as being the planet Gothos), Dr. McCoy reacted by asking him if there was "a squiggle on your encephalograph".