Cerebro (; Spanish for "brain", from Latin ) is a fictional device appearing in American comic books published by Marvel Comics. The device is used by the X-Men (in particular, their leader, Professor Charles Xavier) to detect humans, specifically mutants. It was created by Professor X and Magneto, and was later enhanced by Dr. Hank McCoy. Publication history Cerebro first appeared in X-Men #7 (September 1964). Concept and creation Cerebro first appeared in X-Men #7 (1964). Professor Jeffrey J. Kripal, in his 2011 book Mutants and Mystics: Science Fiction, Superhero Comics, and the Paranormal, calls Cerebro "a piece of psychotronics" and describes it as "a spiderlike, Kirby-esque system of machines and wires that transmitted extrasensory data into Professor Xavier's private desk in another room". Kripal notes that Cerebro made multiple subsequent central appearances, including Giant-Size X-Men #1 (1975), where Cerebro senses and locates a supermutant across the globe, resulting in the recreation of the X-Men team. Use and function of the device Cerebro amplifies the brainwaves of the user. In the case of telepaths, it enables the user to detect traces of others worldwide, also able to distinguish between humans and mutants. Depictions of its inherent strength have been inconsistent; at times in the storylines it could detect mutated aliens outside of the planet, when at others it could only scan for mutants' signatures in the United States. It is not clear whether it finds mutants by the power signature they send out when they use their powers or by the presence of the X-gene in their body; both methods have been used throughout the comics. Using Cerebro can be extremely dangerous, and telepaths without well-trained, disciplined minds put themselves at great risk when attempting to use it. This is due to the psychic feedback that users experience when operating Cerebro. As the device greatly enhances natural psychic ability, users who are unprepared for the sheer enormity of this increased psychic input can be quickly and easily overwhelmed, resulting in insanity, coma, permanent brain damage or even death. The one exception has been Magneto, who has been said to have minor or latent telepathic abilities as well as experience amplifying his mental powers with mechanical devices of his own design. Kitty Pryde once upgraded Cerebro so that non-telepaths could use the device. This was during the time that Professor Xavier was with the Shi'ar and Rachel Summers had just left