This is neither about the poem by Edgar Allan nor Inception. It is just a personal experience which made me curious about what makes this possible. The human brain is mysterious and performs incredible functions, most of which are not entirely understood how, even now. Sleep and dream being another incredulous field which is astonishing, as to how being unconscious the brain is still functioning. The question is, does our brain work when we are asleep? If yes, then how? What is a ‘dream within a dream’? For understanding these, we need to know first what a dream is, and how we dream when we are asleep. But then, what really is sleep? Are we really unconscious when we are asleep?
Well, sleep is not a state of unconsciousness; however, it is an active process which is done by coordination and integration within various parts of brain. Our brain is in the state of awareness with our muscles and physical activity being lowered during sleep. When we are asleep our brain transmits messages by firing neurons either by recalling the events in the day time (that is by firing the same way it did when awake), or, can have an entirely new way to connect.
Sleep is important to restore our immune system, enable learning and consolidate our memory. With the advancement of technology, it is now possible to track the activity of brain with the help of various instruments like electroencephalography (EEG), single photon emission tomography (SPET) etc. These gave us the stages of sleep (see Figure 1) and described the three basic states of our brain: Non- Rapid Eye Movement (NREM), Rapid Eye Movement (REM), and awake state (in the order of the deepest sleep to awakening).
Starting off with the deepest part of sleep – NREM, it can be further divided into four stages, which actually covers 75-80% of total sleep time. In each stage, the coordination between the neurons increase, which is called synchronization. This results in very slow frequency and high amplitude of brain waves. Low frequency of brain waves implies a resting phase of the brain. This further implies that metabolism and blood flow decrease compared to wakefulness (in order of 5-10%, in the early stages, and up to 25-40% in the later stages).
Going on to the next phase – REM, it can be said that during REM (20-25% of total sleep time) the neural synchronization loosens. The brain activity increases, which implies that our neurons are very active. This means that we have a quite active thought process during this time. Thus, this is when most dreaming occurs. Also, our eyes jerk quickly in different directions – which makes sense why this stage is called REM. High brain activity also leads to increase in metabolic activity and blood flow, which kind of mimic wakefulness. However, in this stage there is complete loss of skeletal muscle movement (known as atonia), which is quite unlike to what happens when we are awake. This means that we are kind of paralyzed in this stage due to nerve pathways in the brain that prevent muscles from moving during this stage. Therefore, the difference between REM and wakefulness is caused by the activity of different regions of the brain. As already mentioned, the active state of the brain, during sleep, leads to the experience of dreaming. Dreaming includes the integration of new information from the day, as called the “day residue” by Freud, in early 20th century, and some previous memory in a different episode of sleeping. Hence, activation of different parts of the brain and different combination of neuron firing makes us dream differently.
Study of dreams, called oneirology, started in the early 20th century, which was mainly considered to be psychological analysis, until Aserinsky and Kleitman made the discovery of REM. After this, it was believed that only during REM (observed by rapid eye movement), did people dream. However, dreams are not only confined to REM; it has been found that small burst of activity of brain during NREM are also responsible for inducing dreaming process. These are called sleep spindles which are majorly responsible for memory recalling and learning process. Hence, while the most vivid dreams happen during REM, the restorative dreams occur during NREM. Now we know why and how we dream to some depth. So, we are now ready to dig deeper and reveal what a ‘dream within a dream’ is.
The brain states are not completely active always, and they might also get engaged partially during sleep. The transition between the stages could be partial as well, which leads to the different dreaming conditions – one being ‘dream within a dream’, or, more commonly known as ‘false awakening’. It is said that the hybrid between REM and awakening state makes this happen. However, the awake state is when the dorsolateral prefrontal cortex (refer to Figure 2) of the brain is partially active and makes one aware of self. This is skipped during a ‘dream within a dream’. Hence, we are fooled that we are awake, even being fully in a dreaming state, in reality. Therefore, this happens when the brain is moving towards the fully active state, but it is somehow fooled to assume that it has arrived at the fully active state already – the result being that we are nothing, but awake, in the dream!
The general symptoms of such a dream are that certain aspects of life may be dramatized or out of place, and that there may be more than one false awakening in a single dream (for example, one might dream of waking up, getting up from the bed, talking to family, having tea, etc., and again end up waking up and doing things similarly or differently, which are nothing, but dreams, and this ‘virtual’ waking up and doing stuffs might be repeated in further cycles).
There are two types of false awakening. In the first type, the person dreams of waking up, but not necessarily in realistic surroundings (like an unrealistic ‘late for school/college/work’ scenario), while in the second type, the person dreams of waking up normally, but then realizes that there is something unrealistic about the atmosphere of his/her surroundings (like an unrealistic uncanny atmosphere or unrealistic sounds or movements of something, which is itself unrealistic). Scientists have found that the first type is more common than the second type. It has also been found that there is a strong correlation between such false awakenings and lucid dreams (dreams during which the dreamer is aware that they are dreaming, i.e., the dreamer may gain some amount of control over the dream characters, narrative, and environment). So, people dreaming lucid dreams have higher chances of experiencing such a ‘dream within a dream’ scenario.
Now you know what goes wrong, sometimes, when you happen to be awake and doing stuffs, but then realize that none of it are actually done when your phone beeps. But wait, is your phone actually beeping or have you ended up in another such dream?
Eeshita Ghosh* and Diptatanu Das**
*Department of Biological Sciences, IISER Bhopal
**Department of Biological Sciences, IISER Kolkata
Eeshita Ghosh, Department of Biological Sciences, IISER Bhopal
Buzzi, G. (2019). False awakenings in lucid dreamers: How they relate with lucid dreams, and how lucid dreamers relate with them. Dreaming, 29(4), 323–338. https://doi.org/10.1037/drm0000114
About the Authors:
Eeshita is a third-year BS-MS student at IISER Bhopal majoring in Biology. She is especially interested in molecular and plant biology. She loves painting and dancing other than reading interesting science articles and blogs. She also shows enough interest in sleeping, cooking new dishes and trying good food. She is a regular blogger of our blog page, ‘The Qrius Rhino’.
Read her other blogs for TQR: An Exemplar of Our Incredible Kinship With Plants and The Obscure Flair Of A Plant To Hear Your Words
Diptatanu is a third-year BS-MS student at IISER Kolkata and a KVPY fellow, majoring in biology, with a chemistry minor. He has been a part of the gold-medalist iGEM IISER Kolkata teams in 2018 and 2019, and is also associated with next year’s team. Other than having a high affinity for good food and sleep, he loves to make music and play TT, football, cricket, etc., in his free time. He prefers to do some original work and has been writing articles, blogs and composing new songs. He is also one of the admins and a regular blogger of our blog page, ‘The Qrius Rhino’.
Read his other blogs for TQR: Dragon’s Triangle – The Pacific Ocean’s Deadliest Enigma, How Good Is Gaming?, Life@iiserkolkata, Impacts of Natural Disasters on Ecological Balance – An Original Perspective, iGEM in India!, Coronavirus – An Unsolvable Challenge? and A Summer in Germany!