Why do our dreams feel so real?

And why we don't question their logic.

Dreams can be ludicrous, but unless we are lucky enough to be lucid dreamers, we believe every part of them. Why are you drinking champagne on a private jet with Rihanna? Why is that bumblebee telling you that you’ve hurt your girlfriend’s feelings? Why are the cybermen chasing you?

These are all questions we do not have until we wake up, and only then if we actually remember our dreams in the first place.

Dreams are our one true escape from the humdrum predictability of real life. They are better because they feel so real and are better because we do not question their logic.

But why do they feel so real? Is it our subconscious telling us something? A message from God? A vision? These questions have been debated by philosophers and drunkards alike for centuries, but modern science can now provide very real answers.

According to Dr William MacLehose, a lecturer in the History of Science and Medicine at University College London, until the 1700s, scientists explained dreaming by saying that imagination was the only part of the brain still functioning while someone slept. They believed the part of the brain that verified reality, on the other hand, was out of action, so the sleeper believed it all. Medieval texts referrred to soldiers who were too cowardly to fight an enemy in real life but then dream about being brave enough to do so later on.

In the 20th century, the groundbreaking neurologist Sigmund Freud believed dreams were a form of “wish fulfillment” and that wet dreams were the ultimate expression of that “wish fulfilment”.

Scientists today can tell whether someone is dreaming and what they might be dreaming about by simply looking at electroencephalogram (EEG) scans. The study published earlier this year in Nature Neuroscience was the first to demonstrate that brain activity while dreaming mirrored that of the subject when he or she was doing the same thing when awake. For example, the same parts of the brain recruited in facial recognition were recruited during dreams which included faces.

While most of us do not have to think about engaging an enemy in battle, as medieval dreamers did, a similar theme persists in our dreams today as Professor Mark Blagrove, a sleep scientist from Swansea University suggests – our dreams are about solving real life problems.

Studies have shown that when people are asked to note down the contents of their dreams, the vast majority are based on our real lives. Blagrove notes that while we remember the wild and crazy ones more, they only make up about one in ten of our dreams.

These studies have also found that dreams in which we overcome threats are far more prevalent than the number of threats we face in modern life. When people are asked to detail their dreams, they manage to overcome a large proportion of the threats in a realistic manner, rather than say flying away to Havana.

Dreams feel so real, Blagrove says, because they are a simulation. When you are on drugs or having a hallucination, you have a reality to compare your experience to. By contrast, when you are sleeping no such alternative exists.

Only about one in 20 times do we catch ourselves dreaming and start lucid dreaming. Blagrove points out that the inability to “spot the bizarreness of our dreams when you’re asleep could have been selected for by evolution”. This is because dreaming could have evolved as a form of threat simulation and that in order to “practise what it’s like being in the world while asleep – you have to believe that the simulation is real”.

Daydreaming is a less extreme version of dreaming. It too is a form of simulation. Sometimes you can get lost in a daydream, and believe the simulation but you can easily snap out of it as you can literally “come to your senses”.

Some dream scientists are attempting to tie dream research into the science of consciousness, which Blagrove says, is itself ultimately just a “simulation of the world”.

We never really notice this simulation when we’re dreaming because the “simulation is so good”. Or in other words, our dreams feel so real for the same reason life feels so real. Your suspicions are confirmed – we’re living in the Matrix.

[See also: From the NS archive: The work of Freud]