Lucid dreaming is somewhat controversial because it sounds “New Age-y,” like reading crystals or undergoing color light therapy — things not everyone believes in. There’s science behind lucid dreaming, though. One study monitored subjects with electroencephalograms (EEGs — a test of the electrical brain activity) as they slept. The participants motioned with their eyelids when they were in the middle of a lucid dream. The EEGs confirmed that they were in REM sleep while they signaled their lucid dream state [source: LaBerge]. The fact that people can have lucid dreams isn’t under dispute. The question is whether or not people can control their dreams. Some scientists claim an enthusiastic yes, while others dismiss it as nonsense.
Other researchers have described the phenomenon of lucid dreaming not as a part of sleep, but as a brief wakeful state, or “micro-awakening”. Experiments by Stephen LaBerge used “perception of the outside world” as a criterion for wakefulness while studying lucid dreamers. Although their sleep state was corroborated with physiological measurements, LaBerge admits the criterion is subjective. Physiologically, brain activity during REM sleep is similar to wakefulness. Dr. John Allan Hobson illustrates the ambiguity of these experiments, as LaBerge’s subjects always experienced their lucid dream while in a state of REM. Hobson concludes that lucid dreaming is a state of both waking and dreaming. Fellow dream researcher Michael Schredl found Hobson’s conclusion to be over-simplifying, saying that the physiological state of lucid dreamers appears to be closer to other states of consciousness, such as meditation, than to wakefulness.
We aren’t sure what’s going on in the brain during lucid dreaming. According to Dr. Matthew Walker, director of a sleep lab at Berkeley, the lateral prefrontal cortex, a part of the brain that deals with logic, may be responsible During REM sleep, this part of the brain is supposed to be “asleep,” but it’s possible that it “wakes up” so that dreaming and logic are both working at the same time, enabling the dreamer to recognize the dream situation for what it is.