Mind uploading, whole brain emulation, or substrate-independent minds, is a use of a computer or another substrate as an emulated human brain. The term "mind transfer" also refers to a hypothetical transfer of a mind from one biological brain to another. Uploaded minds and societies of minds, often in simulated realities, are recurring themes in science-fiction novels and films since the 1950s. Early and particularly important examples A story featuring an artificial brain that replicates the personality of a specific person is "The Infinite Brain" by John Scott Campbell, written under the name John C. Campbell, and published in the May 1930 issue of Science Wonder Stories. The artificial brain is created by an inventor named Anton Des Roubles, who tells the narrator that "I am attempting to construct a mechanism exactly duplicating the mechanical and electrical processes occurring in the human brain and constituting the phenomena known as thought." The narrator later learns that Des Roubles has died, and on visiting his laboratory, finds a machine that can communicate with him via typed messages, and which tells him "I, Anton Des Roubles, am dead—my body is dead—but I still live. I am this machine. These racks of apparatus are my brains, which is thinking even as yours is. Anton Des Roubles is dead but he has built me, his exact mental duplicate, to carry on his life and work." The machine also tells him "He made my brain precisely like his, built three hundred thousand cells for my memory, and filled two hundred thousand of them with his own knowledge. I have his personality; it is my own through a process I will tell you of later. ... I think just as you do. I have a consciousness as have other men." He then explains his discovery that the electrical impulses in the brain create magnetic fields that can be detected by a device he built called a "Telepather", and that "[t]hrough this instrument any one's mental condition can be exactly duplicated." Later, he enlists the narrator's help in constructing a new type of artificial brain that will retain his memories but possess an expanded intellect, though the experiment does not go as planned, as the new intelligence has a radically different personality and soon sets out to conquer the world. An early story featuring technological transfer of memories and personality from one brain to another is "Intelligence Undying"