Lucid nightmares: what they are and why they appear
One of the most widely reported experiences in sleep studies is that of awareness of and even control over one’s sleep. There are even techniques and trainings to induce this type of experience and achieve pleasant emotions even when we sleep. But pleasant experiences are not the only ones that often occur.
On the contrary, there is another frequently reported experience: having lucid dreams characterized by an experience of anguish and the inability to return to vigil. These are the lucid nightmares .
We will now see what the main characteristics of these nightmares are and how they have been explained by some scientific research.
What are lucid nightmares?
We know lucid those dreams where the person is aware that he is dreaming . These are usually positive experiences, whose content generates pleasant emotions, and whose course is easily influenced by the person who is dreaming. However, this is not always the case.
Lucid nightmares are a type of lucid dreams characterized by a frightening context and by a lack of control during sleep. Just like common nightmares, lucid nightmares generate anguish and anxiety, but in the case of the latter an extra stressor is added: there is the intention to wake up, but there is an inability to do so.
These dreams were first described in 1911, when the Dutch psychiatrist and writer Frederick van Eeden coined the term “lucid dreaming”, referring to mental clarity during the dream state, as well as the awareness of being in that state.
Main characteristics
In a study conducted by sleep science psychologist Tadas Stumbrys (2018), more than 600 participants were surveyed online about their experiences with lucid nightmares. The following common characteristics were found as a result:
- There is awareness of the dream state .
- However, there is a significant sense of lack of control.
- Intense fear remains .
- Violent characters are presented who seem to have autonomy beyond the person who is dreaming, and even decide against the wishes of the person himself.
- There’s an inability to wake up.
The same study showed that lucid dreaming was common in more than half of the population surveyed, but lucid nightmares were reported by less than half. They also found that those who had frequent lucid dreams also had greater control over their dream patterns, as well as better abilities to reduce distress during lucid nightmares. That is, they perceived them as less threatening .
However, these same people also experience lucid nightmares more frequently (compared to people who do not usually have lucid dreams), and the intensity of the distress experienced does not depend on the frequency of the lucid dreams. Thus, although they have more control over the feelings of distress during sleep, they are more likely to experience them .
Why do they happen?
As we have said, the content of lucid nightmares is by definition threatening . Sometimes it can generate near-death experiences, and even these experiences can correspond to real life upon awakening. One example is the record of cases of people who, after dreaming that someone shot them in the heart, wake up in the middle of a myocardial attack (McNamara, 2012).
But is it a set of hallucinations? How do lucid nightmares occur? This is not strictly speaking a hallucination , since there is full awareness that the movements, actions, emotions, environment and characters that are being experienced are not part of the objective reality of the vigil, although it seems to be the opposite.
Lucid nightmares, like lucid dreams, emerge in the REM phase (Rapid Eye Movement) which means rapid movement of the eyes, and is the phase of greatest activity in the brain. This activity is, in fact, similar to that of the waking state, however it includes a slight blockage of neurons in charge of voluntary motor regulation.
But lucid nightmares do not only occur in the REM phase, they occur during the transition from REM to non-REM sleep, or in a partial REM entry phase. Non-REM is the slow wave phase and is characterized by introducing us to deep sleep. It manifests variations of brain activity and may contain hallucinations on entry or exit.
Thus, lucid nightmares occur in a state of partial sleep, where the brain does not register complete rest activity, but neither does it register complete wakefulness.
Characteristics of brain activity in lucid nightmares
Unlike common dreams, during the REM phase of lucid dreaming the brain shows increased activity of the prefrontal and occipito-temporal cortex, as well as the parietal lobes. These are the areas that are theoretically deactivated during REM sleep in ordinary dreams.
This seems to indicate that lucid dreaming is a phenomenon that does begin in this phase (maintaining some of its characteristics, such as muscular paralysis), but does not develop completely in REM, since has important differences at the cerebral level .
Similarly, the above-mentioned brain areas can explain the state of consciousness of dreams and lucid nightmares, as well as logical thinking, decision-making and the anguish generated by threatening stimuli combined with the inability to wake up .
However, explanations of the particular content of lucid nightmares, their duration and frequency, as well as the individual experience of distress, require deeper approaches.
Bibliographic references
- McNamara, P. (2012). Lucid dreaming and lucid nightmares. Psychology Today. Retrieved September 21, 2018. Available at https://www.psychologytoday.com/us/blog/dream-catcher/201207/lucid-dreaming-and-lucid-nightmares.
- Stumbrys, T. (2018). Lucid nightmares: A survey of their frequency, features, and factors in lucid dreamers. Dreaming, 28(3), 193-204.
- Stumbrys, T., Erlacher, D., Schädlich, M. and Schredl, M. (2012). Induction of lucid dreams: A systematic review of evidence. Consciousness and Cognition, 21(3): 1456-1475.