“A merry little surge of electricity piped by automatic alarm from the mood organ beside his bed awakened Rick Deckard.” The characters in Philip K. Dick’s 1968 novel Do Androids Dream of Electric Sheep? fine-tune their mental and emotional states with the “Penfield Mood Organ,” a device named after neurosurgeon Wilder Penfield, known for his research on electrical brain stimulation. This fictional apparatus remarkably resembles modern non-invasive transcranial brai...