The Activation-Synthesis Hypothesis proposes that dreams are the brain's attempt to make sense of random neural signals during sleep.

Developed by J. Allan Hobson and Robert McCarley at Harvard University, this theory suggests that dreams originate from spontaneous bursts of electrical activity in the brainstem (pons) during REM sleep. These random signals are then sent to the forebrain, which attempts to synthesize them into a coherent narrative, drawing upon stored memories, emotions, and external stimuli. The vivid, often illogical nature of dreams, according to this view, is a byproduct of the forebrain trying to impose meaning on intrinsically meaningless data. While it doesn't deny a potential function of REM sleep, it largely attributes dream *content* to arbitrary neural activity.