Why do we have dreams?
1. The Nature and Function of Dreams by Rachel Berman:
Most dreams occur in REM (Rapid Eye Movement) sleep.
During the time of Freud (1856-1939) no knowledge of Inhibitory neurons was at hand, only Excitatory neurons were considered. Freud concluded that "nervous energy" - caused by some excitation, perhaps by a thought - wanders around until it finds a way to manifest itself may be in the form of visual imagery or dream.
Drs. Allan Hobson and Robert McCarley proposes the "Activation-Synthesis Model" : dreaming is caused physiologically by a “dream state generator,” which is located in the brain stem. It is “on” during REM sleep, while all sensory input and motor output are blocked, and the neurons in the cerebral cortex are activated by random impulses that generate sensory information within the nervous system. As Hobson and McCarley put it: “the activated forebrain then synthesizes the dream out of internally generated information, trying its best to make sense out of the nonsense it is being presented with."
Hobson’s and McCartey’s treatment of symbol formation is also in direct opposition with Freudian conception. They believe that “bizarre features” of a dream world are simply a reflection of the bizarre state (the bombardment with internal excitory signals, etc.) of the dreaming brain. That is, in the construction of a dream “the forebrain may be making the best of a bad job in producing even a partially coherent dream imagery from the relatively noisy signals sent up to it from the brain stem.” This implies that dreams have no emotional content since they are triggered only by sensory and motor aspects of bodily activity.
2. Dreams - Physiology:
We dream about 2 hrs a day. Lucid dreaming is when one becomes aware of one's own dreaming and may be able to control it.
3. Physiology and Psychology of Dreams by Alan S. Eiser: Though it has been found out that 80% of REM awakenings yield dreams, there are significant mental activities in NREM also. Typically, it is more thought like, fragmentary, and related to daily concerns than the vivid, hallucinatory, predominantly visual narratives that are most commonly reported from REM sleep. But even this distinction appears not to be absolute. There is now wide acceptance of the view that some dreaming that is indistinguishable from REM sleep dreaming occurs in NREM sleep, most frequently in the sleep-onset period.
It is a centrally important observation that dreaming undergoes a process of development and that it must be viewed in the context of the child’s developing cognitive capacities.
