During lucid dreams, the sleeper is aware a dream is taking place but will not leave the dream state. Some further define these phenomena as dreams in which the sleeper can exercise control over different aspects of their environment, though studies have found this is not always the case, and that certain people are more predisposed to “lucid dream control” than others.
Surveys show that roughly 55% of adults have experienced at least one lucid dream during their lifetime, and 23% of people experience lucid dreams at least once per month. Some research has pointed to potential benefits of lucid dreaming, such as treatment for nightmares. However, other studies argue lucid dreams may have a negative impact on mental health because they can disturb sleep and cause dreamers to blur the lines between reality and fantasy.
Lucid dreaming has been studied extensively, but much is still unknown about the phenomenon. Some researchers believe activity in the prefrontal cortex of the brain is related to the development of lucid dreams. During non-lucid dreams, people are cognizant of objects and events within the dream state, but they are not aware of the dream itself and cannot distinguish being asleep from being awake. This has been attributed in part to lower levels of cortical activity.
Lucid dreams are different because sleepers are aware they are dreaming and, in some cases, can exert control over their surroundings. Some studies have linked these characteristics to elevated cortical activity. In sleepers who have been observed during lucid dream studies, prefrontal cortex activity levels while they are engaged in lucid dreaming are comparable to levels when they are awake. For this reason, lucid dreaming may be referred to as a “hybrid sleep-wake state.”
While normal dreams can occur during different stages of the sleep cycle, studies have shown most lucid dreaming takes place during rapid eye movement (REM) sleep. REM sleep constitutes the fourth and final stage of a normal sleep cycle; the first three stages consist of non-rapid eye movement (NREM) sleep. The general consensus among researchers today is that lucid dreams originate from non-lucid dreams during the REM sleep stage. In this sense, lucidity is an aspect of dreams that can be triggered using different means.
Spontaneous lucid dreams are rare and difficult to foresee. To study these phenomena, researchers typically induce lucid dreams using different methods. Some of the most common techniques include the following:
Additionally, some studies have involved inducing lucid dreams using certain types of drugs and supplements.
Once a subject has fallen asleep, researchers can levels of activity in the prefrontal cortex and other areas of the brain using a device known as an electroencephalogram (EEG), during which metal discs are attached to the subject’s scalp. An electrooculogram (EOG) may also be used to track eye movements to determine when the subject enters REM sleep. For some studies, subjects are asked to make specific eye movements while sleeping to signal they are having a lucid dream. EOGs are particularly helpful for detecting these movements.
The popularity of self-induced lucid dreams has grown in recent years. The most common reasons for inducing lucid dreams include wish fulfillment, overcoming fears, and healing. Some studies have also shown a link between inducing lucid dreams and overcoming the fear and distress associated with nightmares.
Some researchers have introduced another problem with lucid dreams: they are potentially disruptive to sleep. Since lucid dreams are associated with higher levels of brain activity, it has been suggested these dreams can decrease sleep quality and have a negative effect on sleep hygiene. Frequent lucid dreams could potentially restructure the sleeper’s sleep-wake cycle, which in turn may affect emotional regulation, memory consolidation, and other aspects of day-to-day life linked to sleep health. Additionally, people with narcolepsy – a sleep disorder characterized by excessive daytime sleepiness and irresistible sleep attacks – are more likely to experience frequent lucid dreams.
The study of lucid dreams is fairly new and largely incomplete. More research is needed to better understand these types of dreams and pinpoint why some people are predisposed to more frequent and intense lucid dreams.
Triggering lucid dreams can be fairly easy with the right methods. Those who are inexperienced with these phenomena may be able to induce a lucid dream for themselves through the following means:
Other techniques may be used to induce lucid dreams. These include transcranial direct current stimulation (tDCS), which painlessly applies electrical currents to different areas of the brain, and certain types of medications. There is little scientific research to demonstrate the effectiveness of these methods. These techniques are also only conducted in controlled clinical laboratory settings and should never be attempted by an individual unless under the supervision of a doctor or another credentialed medical or psychological professional.