In his theory of consciousness, American biologist Gerald M. Endelman proposes two distinct forms of consciousness: primary and secondary. Primary consciousness is characterized by concreteness along with perception of, reaction to, and learning from the immediate present. On the other hand, secondary consciousness involves additional features of abstract thinking, self-reflexive awareness, volition, and metacognition (the ability to reflect on one’s own mental states).
Normally, dreams are characterized by primary consciousness. Lucid dreams, however, are a rare phenomenon in which primary and secondary consciousness converge. Simply defined, lucid dreams are a state of consciousness in which the dreamer becomes aware of the fact that they are dreaming, without leaving the sleeping state. These occur as a result of the reactivation of specific brain areas, particularly the dorsolateral prefrontal cortex and the cuneus, that are normally inactive during Rapid Eye Movement (REM) sleep. Dorsolateral prefrontal cortex is associated with higher order cognitive processes such as critical thinking, volitional control, and metacognition. The precuneus is associated with self-referential processing. The reactivation of these two brain regions restores the dreamer’s self-reflexive capacity and metacognitive monitoring of the dream content, thereby allowing the dreamer some extent of control over the plot and landscape of the dream.
Lucid dreams have captured the collective imagination of masses, largely due to sci-fi thriller movies like Inception and Vanilla Sky. Lucid dreaming, a state of altered consciousness which allows for volitional manipulation of perceived reality, is the ultimate immersive experience. However, spontaneous lucid dreaming is not as frequent as one would like. A meta-analysis by Saunders et al., (2016) based on 50 years’ worth of data revealed that over 55% people report having experienced at least one lucid dream over their lifetime. However, only 23% claim to have experienced lucid dreams as often as once or twice a month. It comes as no surprise, therefore, that techniques to deliberately induce lucid dreams have been gaining popularity in recent years. These techniques can be classified into three broad categories: cognitive techniques, use of external stimuli, and intake of specific drugs.
Cognitive techniques include cognitive activities to induce lucid dreaming without specialised equipment. One such way is to conduct ‘reality tests’ during the day, in an attempt to train oneself to recognize the incongruencies in one’s environment that can be indicative of a dream state. In this manner, the practitioner may eventually perform such reality checks while dreaming and successfully recognise when they are dreaming. Another cognitive technique, the Mnemonic Induction of Lucid Dreams (MILD), recommends that the practitioners repeat to themselves, their intention to be aware of dreaming, prior to falling asleep. This relies on prospective memory, or the ability to remember to perform pre-planned actions. If successful, the practitioner will remember this intention during REM sleep and attain lucidity while dreaming. The MILD technique is often used in combination with the Wake Back To Bed technique (WBTB). This requires the practitioner to set an alarm to wake up after a significant stretch of sleep, only to go back to sleep after remaining awake for a short period of time. This short waking period provides an ideal time to practice the MILD technique, increasing the chances of success as REM sleep is entered more quickly later during the sleeping period.
Stimulation methods involve delivering external stimuli such as flashing lights, mild electric shocks, acoustic, or tactile stimuli during REM sleep. These sensory stimuli serve as a cue to alert the practitioner that they are dreaming, without waking them up. A number of non-commercially available portable devices to induce lucid dreaming have been designed on the basis of this mechanism.
The final category of techniques to induce lucid dreams consist of administering acetylcholinesterase inhibitors such as donepezil and galantamine, in combination with the aforementioned techniques. In theory, these substances increase the availability of acetylcholine (a neurotransmitter that facilitates arousal) in the cerebral cortex, thus stimulating lucid dreaming.
It is important to note, however, that all the techniques discussed above come with pitfalls. WBTB and MILD techniques may result in disruption of normal sleep architecture owing to a decrease in duration and increase in fragmentation of sleep. Scheduled awakenings during the night and reality tests during the day may blur the boundaries between sleep and wakeful states. Similarly, external stimuli run the risk of unintentionally rousing the practitioner as well as decreasing sleep depth and duration. Intake of acetylcholinesterase inhibitors in absence of brain pathologies that warrants its use may disrupt the intricate balance maintained by neurotransmitter systems that regulate sleep.
Therefore, one cannot help but wonder if lucid dream induction for recreational purposes is worth risking the adverse health effects associated with insufficient or poor-quality sleep. Moreover, prefrontal cortical activity, despite its adaptive value, is not a part of regular sleep and dream states, and is probably inhibited for a good reason. It has been suggested that by allowing vigilance to permeate into nocturnal consciousness, lucid dreamers may be compromising on restful sleep. Correlational evidence suggests spontaneous lucid dreaming has been found to be associated with poor sleep quality.
Induction of lucid dreaming is not limited to recreational purposes; it has potential clinical applications. Lucid dreams carry important physiological links to psychosis. While lucid dreaming can be defined as awareness during a dream due to abnormal frontal activity in a sleeping state, psychosis is the exact opposite: pervasion of dream-like features in a wakeful state due abnormal frontal inactivity. It has also been suggested as a potential therapy for recurrent nightmares in post-traumatic stress disorder and major depressive disorder. Patients can be trained to simply wake up, become aware that they are dreaming or transform their nightmare into something pleasant. Moreover, lucid dreams provide important insights into our understanding of consciousness and altered states, making it a promising research avenue.
Isha Puntambekar
