Have you ever wished you could fly, or time travel, or live like a king for a day? For a select few people, those dreams are a reality – in their dreams at least. Lucid dreamers are able to consciously manipulate their dreams, turning their nighttime hours into an imaginative playground without boundaries. It's an idea that has long fascinated mankind. While the term lucid dreaming wasn't coined until the early 1900s, the same theory is included in Buddhist teachings, and in 350BC Aristotle wrote: "When one is asleep, there is something in consciousness which tells us that what presents itself is but a dream." However, science only substantiated lucid dreaming in 1975, when psychologist Dr Keith Hearne trained his experimental subjects to use ocular signalling to indicate they were in a lucid dream state. The subjects signalled their consciousness during the dream by moving their eyes left to right eight times. By using lucid dreams to work through challenging situations in your waking life, you naturally begin to realise you also have the power to create the day-to-day reality you want to live inIan Wallace The immediate appeal of lucid dreaming is obvious: it offers the superhuman ability to control the world you 'live' in, if only for a few seconds or minutes. The dreams can be used for pleasurable experiences, or to resolve waking-life tensions and stress. Or you could play out challenging situations before they happen – a particularly difficult exam or presentation, perhaps,. "Part of the excitement of lucid dreaming is the realisation that you have the power to do anything you wish in the world in your dream," says Ian Wallace, a psychologist, dream expert, and author of The Complete A to Z Dictionary of Dreams. "By using lucid dreams to work through challenging situations in your waking life, you naturally begin to realise you also have the power to create the day-to-day reality you want to live in." Historically, artists, scientists and inventors are said to have used them to seek inspiration. "Some of those tales may be apocryphal," Wallace explains. "But it is highly likely creators and innovators use lucid dream experiences to explore creative options that may not be obvious from a routinely analytical and objective perspective." Einstein, in particular, is thought to have used them to help formulate his theories. "One of the main qualities associated with creators, inventors and artists is their capacity for deep play, where they can become so absorbed in their particular area of interest that they enter into a flow state, unconsciously shutting out any other influences that are of no relevance." Lucid dreaming takes this a step further by creating an "organic virtual reality experience" where different scenarios can be played out and experimented with. Lucid dreaming happens during the rapid eye movement (REM) periods of sleep, which can take place four times a night. "It's is most likely to occur during the hypnagogic and hypnopompic states between waking and sleeping," says Wallace. "With practice, they can be generated in any part of REM state sleep." Although lucid dreamers remain asleep, they have "a significant level of self-awareness, self-reflection, intention, motivation and access to memory." The difference between lucid and normal dreams, in terms of consciousness, is relatively straightforward. Researchers comparing brain activity in both have discovered that in regular dreaming there is a basic level of consciousness. We can perceive and experience emotions, for example, but we aren't aware we're actually dreaming. Conversely, scientists have found that the areas of the brain responsible for higher cognitive control, awareness, and emotional processing remain active during lucid dreams. The right dorsolateral prefrontal cortex, for example, which is involved in self-assessment, decision-making and memory, is fully running during the process. Potentially everyone will experience a lucid dream during their life, possibly without fully understanding they're in a lucid dream state, and you don't need an IQ of 160 to have one. Around 20pc of adults lucid dream regularly, with up to half of us experiencing one in our lifetime. During puberty, spontaneous lucid dreaming is common, due to neurobiological changes. How to train yourself to dream lucidly For most people it can take a long time to learn to dream lucidly. For others it comes quickly or naturally. With a little time, practice and dedication, the experts reckon anyone can do it. To Wallace, the first step is to recognise you are dreaming. Take notice of anything that is unusual or out of context in the dream. "As you direct your attention to what appears strange in your dream, the awareness that you are dreaming will naturally begin to emerge for you." You could keep a dream journal detailing the weird things you experience, so when you return to that dream state, it makes it easier to be conscious of them. Keeping a regular sleeping schedule is also recommended. If you sleep and wake at the same time each day, your brain will settle into a routine and a cycle of sleep, making it more likely to enter dream stages during the night. Another commonly used technique for beginners, according to lucidity.com, is reality testing. To do this, you should assign several moments per day to practice. For the first step, keep some text or a digital watch with you. Read the words or numbers, look away, and look back, and see if the letters or numbers change. In dreams, the text will usually change when it is re-read. If there's no change, you probably aren't dreaming. Next, imagine your surroundings: if you're pretty sure you're awake, tell yourself "I may not be dreaming now, but if I were, what would it be like?" Imagine everything you see, hear, smell and feel is a dream. Keep that feeling and move to the final step, which is to decide something you want to do in your next lucid dream. Keep imagining you are dreaming and visualise yourself enjoying the activity. Hopefully, you'll then be able to dream it. If the reality testing doesn't work, you could simply try napping. An experiment in the 1970s found that lucidity came easiest during afternoon naps; a light sleep with periods of wakefulness is believed to be the best incubator of lucid dreams. One study has shown that your 15-20 times more likely to lucid dream during napping than not. If you don't manage to, at least you've had a good kip. This can be done in the morning, too, which Wallace believes is the best time. You could try setting your alarm an hour early and lying in a half-asleep state. "As you wake, you have the opportunity to hover in that area between sleeping and waking," Wallace explains. "You can become aware that you are dreaming as you wake and make the decision to remain in that state. To begin with, you will probably just continue to wake up but with practice you can maintain the lucid state for longer." Wallace suggests avoiding artificial methods, such as using technology, to aid lucid dreaming. "LED masks, for example, can be hit and miss and may induce undesired results. Taking any form of lucid dreaming supplements can also cause unpleasant experiences," he says. "One of the fundamental values of lucid dreaming is that the dreamer is autonomously generating their own dream experience, rather than relying on external aids. The more autonomous the dreamer is, the more connected they will be with their intentionality and their power to make choices."