Lucid dreaming remains an area of ongoing research, and with the newer tools of brain imaging including functional MRI (fMRI), the ability to analyse the measure the effects of lucid dreaming are growing.
One area of interest is trying to locate what parts of the brain are involved in lucid dreaming, and how they are connected in ways that might differ from normal.
What is Lucid Dreaming?
Lucid dreaming is most simply expressed as the state of being aware that one is in a dream, i.e. the state of being ‘lucid’. With this might come increased ability to control elements of the dream, or the direction of dream events.
It is a state encountered naturally, much more by some individuals than others, but can also be cultivated through practice of a number of induction techniques.
Although met with some initial skepticism, lucid dreaming has slowly gained ground as an accepted and valid area of scientific research. One example which helped establish its credibility was a study published in 1981 which showed lucid dreamers could intentionally direct their eyes in a particular direction, indicated a form of non-random control while dreaming (LaBerge et al., 1981).
Another similar study, reinforcing the notion, showed activation a part of the brain associated with motor function (i.e. movement), upon dreaming of hand clenching (Erlacher et al., 2003).
Locating Lucid Dreaming In The Brain
Normally, the parts of the brain referred to as the prefrontal cortex, parietal cortex and lateral middle temporal cortex show relatively low levels of activity during sleep, particularly REM sleep, as measured by local blood flow. REM sleep is the stage of sleep most associated with dreaming, and therefore these would seem unlikely to be involved in lucid dreaming.
Despite this, there is some evidence that it is precisely these areas which are involved in lucid dreaming (Dresler et al., 2012). One region in particular which seems to have some support in the scientific literature, is the anterior pre-frontal cortex (aPFC). This is an area involved in metacognition, including activities such as self-reflection on one’s inner thoughts and emotions (McCaig et al., 2011).
Recent Research Into Lucid Dreaming
A more recent study published in Nature (Baird et al., 2018) took a particular focus on the aPFC and used sophisticated methodology to assess its role in lucid dreaming. Compared to normal people, they found that people who experience high rates of lucid dreaming (every second night or more), had increased connection between the anterior prefrontal cortex (aPFC) and the bilateral angular gyrus (AG), bilateral middle temporal gyrus (MTG) and right inferior frontal gyrus (IFG), but decreased connection between the left hand side aPFC and the bilateral insula. For some reference on the neuroanatomy see here.
The authors infer from this that the “current results suggest that increased functional integrity during wakefulness between aPFC and temporoparietal association areas—all regions that show suppressed activity in REM sleep and increased activity during lucid REM sleep—is associated with the tendency to have frequent lucid dreams” (Baird et al., 2018, p. 6)
Further to this, and in line with the neuroanatomy involved, they link lucid dreaming to metacognition – the ability to recognise, reflect on and have insight into one’s state of mind. This in turn raises questions about what benefits the cultivation of lucid dreaming might offer, in terms of self awareness and self control.
Inducing Lucid Dreaming
The study by Baird et al. (2018) used participants described as having lucid dreams, but did not make any mention of wether the lucid dreaming group studies had practiced to develop lucid dreaming, or simply developed it spontaneously. This is a methodological problem because it leaves unanswered the question of whether practicing lucid dreaming induction techniques changes the connectivity of the brain, as found in the studied individuals, or whether it is a more temporary effect.
Lucid dreaming remains a fascinating area and the subject of an increasing body of research. Its benefits seem destined to grow as it is understood more and more, and the possibilities fully explored.
Baird, B., Castelnovo, A., Gosseries, O. et al. Frequent lucid dreaming associated with increased functional connectivity between frontopolar cortex and temporoparietal association areas. Sci Rep 8, 17798 (2018). https://doi.org/10.1038/s41598-018-36190-w
Dresler, M. et al. Neural correlates of dream lucidity obtained from contrasting lucid versus non-lucid REM sleep: A combined EEG/fMRI case study. Sleep 35, 1017–1020 (2012).
Erlacher, D., Schredl, M. & LaBerge, S. Motor area activation during dreamed hand clenching: A pilot study on EEG alpha band. Sleep Hypnosis 5, 182–187 (2003).
LaBerge, S. P., Nagel, L. E., Dement, W. C. & Zarcone, V. P. Lucid dreaming verified by volitional communication during REMsleep. Percept. Motor Skills 52, 727–732 (1981).
McCaig, R. G., Dixon, M., Keramatian, K., Liu, I. & Christoff, K. Improved modulation of rostrolateral prefrontal cortex using real-time fMRI training and meta-cognitive awareness. NeuroImage 55, 1298–1305 (2011).