LIFESTYLE | Activation-Synthesis Model of Dreaming

Activation-Synthesis Model of Dreaming

Here's an article I found at the back of my psychology notebook. Back in UP Diliman, I was so fond of staying in the General Reference Section of the library (on the first floor) to study for some exam, but most of the time I find myself jotting down some trivial information on things that capture my attention. That time I chanced upon this book on dreams and started reading. 



The Activation-Synthesis Model of dreaming was proposed in 1977 by Robert McCarley and J. Allan Hobson of Harvard Medical School. Examining the purely physiological correlates of dreaming, Hobson and McCarley believed that they had put forward a hypothesis that rejected the notion that dreams are meaningful, especially as this notion was formulated by Sigmund Freud and promulgated in the tradition of dream interpretation he initiated.

During rapid eye movement (REM) sleep, the stage of sleep most closely connected with dreaming, a portion of the dreams called the pons (located in the primitive midbrain) generates electrical signals that go to many different brain areas, including those associated with motor activities, sensory activities, and conscious thought. Hobson and McCarley hypothesized that one of the effects of this electrical activity is to send a series of essentially random images, feelings and so forth to the higher mental centers of the forebrain. This is the "activation" stage of the theory.


In normal waking consciousness, the forebrain sorts through various kind of internal and external sensory input to create a meaningful experience of the world. Faced with a barrage of disconnected inputs during REM sleep, the higher mental centers attempt to impose order on the incoming messages, creating whatever narrative structure dreams have. This is the "synthesis" stage of the theory. The many dreams are just masses of incoherent images representing incoming groups of signals that the brain was simply not able to synchronize.

An incomplete theory because it does not offer an explanation for the dreams that occur during non REM sleep.


Reference:
Lewis, James R. 1995. The Dream Encyclopedia. Detroit, USA: Visible Ink Press.