November 29, 2023

I, Science

The science magazine of Imperial College

Harsimran Kaur Sarai considers the big questions of life and death through the lens of lucid dreaming and sleep paralysis.

What is life?

Across the world, life is astoundingly diverse. It consists of units called cells, also known as building blocks, which make up existing bodies. These include multicellular[RM1] animals, which are made from many units, to unicellular bacteria. In animals, including humans, cells form tissues these create vital organs such as the brain, which is responsible for keeping us conscious and able to speak and move. Death is the opposite.

But how can we say definitively if something is dead or alive? Can there be an in-between? Such ideas are normally relegated to the field of philosophy, but the purpose of this article is to discuss these ideas from a scientific perspective.

Why do we dream?

Dreams are the film of images that our brain invents whilst we sleep, governed by our real-life emotions, desires, and past experiences. At night, we go through two stages of sleep: non-rapid eye movement (non-REM) where the body is just beginning to sleep, and rapid eye movement (REM). Most of the dreams we have are during REM sleep – this is why we have bizarre dreams that have us questioning what happened after waking up. Such dreams are called ‘vivid’ dreams, since we can recall parts, or all, of the dream. 

The origins of lucid dreaming

Our brain is divided into four different regions called lobes: frontal, parietal, temporal and occipital. The anterior prefrontal cortex and parietal cortex are located within the frontal lobe and are most operative during lucid dreaming. This is a result of neurons (messengers in the brain that produce electrical impulses) rapidly interacting with each other. The resulting high level of electrical activity allows a dreamer to realise they are dreaming – as this happens, people can control their dreams and choose to do whatever they want to without the restrictions that would apply to real life. Lucid dreaming is therefore a form of vivid dreaming.

Alive – but not?

On the other hand, lucid dreaming can be dangerous. Literature shows some people may experience lucid nightmares, where “demonic figures” try to cause pain to the dreamer. In some cases, people have reported feeling the harm in real life and as a result cannot wake up from the dream, causing intense stress. Such experiences are associated with sleep paralysis, in which the muscles are temporarily paralysed so the body cannot move – but the dreamer is aware of this. If we reflect on the definition of life and death, would it not be fair to say lucid dreaming and sleep paralysis can result in something in-between? After all, in these states the brain [RM1] is still conscious, but the body is unresponsive – even the muscles in the lips cannot move to produce words. It should be noted that this state typically only lasts a few seconds to a few minutes, and so it is perhaps comparable to a near-death experience. Disturbingly, one dreamer who told someone in their lucid dream that “nothing is real”, was told in response “leave before it turns into your end”.

Lucid dreaming as a therapeutic

However, lucid dreaming has also been proven to improve sleeping patterns. For example, researchers have trained people who experience frequent nightmares to lucid dream and found that the[AM1]  average number of nightmares decreased by 60%. One participant shared how she was able to lucidly control a nightmare where someone was chasing her in the dark, and successfully managed to defeat her attacker. Such experiences resulted in an overall improved quality of sleep.

Alzheimer’s disease is a brain disorder which affects a person’s social skills as well as day to day activities. This is because the disease causes decline in memory, lack of muscle coordination and inability to process new information. Unfortunately, these characteristics tend to get worse over time as the condition progresses. Investigation has therefore also been done into seeing if the medicine galantamine can stimulate lucid dreaming, with the hopes that it improves memory in people with Alzheimer’s. It was found that this does indeed happen, as an increase in “cognitive clarity” was seen due to participants being more likely to remember events.

To conclude…

We think of life and death as opposites, but lucid dreaming is just one example in which individuals could be argued to be in both states simultaneously. Life and death may not, then, be as separate as we assume them to be – should we be unsettled or fascinated by this? Or, perhaps, both?

Image via Unsplash.