ABSTRACT
A sequence of studies followed, in quick succession, in which different parts of the brain were systematically removed in order to isolate the precise structures that produced rapid eye movement (REM) sleep. Neuroscientific research into the mechanism of REM sleep continued along these lines, using a wide variety of methods, and by 1975 a detailed picture of the anatomy and physiology of “dreaming sleep” had emerged. The only reliable difference between REM dream reports, sleep-onset reports, and certain other classes of non-REM dream report is that the REM reports are longer. This demonstrates conclusively that fully fledged dreams can occur independently of the unique physiological state of REM sleep. These radiological pictures also reveal something about what happens in between the initial and terminal ends of the dream process. The most striking feature of the dreaming brain in this respect is the fact that a region of the brain known as the dorsolateral frontal convexity is completely inactive during dreams.
