Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Activation-synthesis hypothesis is a neurobiological theory of dreams forwarded by Harvard University psychiatrists James Allan Hobson and Robert McCarley, first published on the American Journal of Psychiatry in December of 1977. It states that dreams are a random event caused by firing of neurons in the brain. This random firing sends signals to the body''s motor systems, but because of a paralysis that occurs during REM sleep, the brain is faced with a paradox. It synthesizes a narrative by drawing on memory systems in an attempt to make sense of what it has experienced.