Dreams (Cont'd)

Another view of the causes of dreams is the activation-synthesis hypothesis, which states that dreaming represents a person's subjective awareness and interpretation of neural activity during sleep. According to Robert W. McCarley and J. Allan Hobson, our acceptance of bizarre occurrences in dreams is caused by changes in brain physiology. That is, just as our brains organize sensory information during wakefulness, our brains also organize sensory information during sleep. For example, the brain may interpret the blockage of motor commands that occurs during dreaming as a sensation of our being chased. In fact, in some experiments, it has shown that the subject had the same eye movements as if the imaginary events were really occurring.

Another form of dreaming is known as lucid dreaming. The term was coined by Frederik van Eeden who used the word "lucid" in the sense of mental clarity. The difference between lucid dreaming and ordinary dreaming is that we are able to control what we dream about, and we are consciously aware that what we are experiencing is a dream. Often this realization is triggered by the dreamer noticing some impossible or unlikely occurrence in the dream, such as flying or meeting the deceased. A minority of lucid dreams (according to the research of LaBerge and colleagues, about 10 percent) are the result of returning to REM (dreaming) sleep directly from an awakening with unbroken reflective consciousness. The quality of lucidity can vary greatly. When lucidity is at a high level, you are aware that everything experienced in the dream is occurring in your mind, that there is no real danger, and that you are asleep in bed and will awaken shortly. With low level lucidity, you may be aware to a certain extent that you are dreaming, perhaps enough to fly or alter what you are doing, but not enough to realize that the people are dream representations, or that you can suffer no physical damage, or that you are actually in bed.