News items Tinkering with Sleep

8 April 2024

Hacking your dreams and taking control, training your memory while snoozing, or stimulating deep sleep to better clear toxins from the brain. In Martin Dresler's Sleep and Memory Lab, these dream scenarios become reality.

You're a superhero in a billowing cape, about to save the world. Will you succeed? Certainly, because you're the director of this movie. You're in the virtual world of your own lucid dream. That's a dream where you realize you're asleep. And that realization gives you the opportunity to actively steer your dream.

Only about half of people have ever experienced such a self-conscious dream in their lives, and even among most of these dreamers, lucid dreams are rare. But if it’s up to a few new companies that's going to change. They're working on equipment to stimulate these dreams. The American startup Prophetic, for example, is developing a headband that activates the brain with sound waves, targeting the market for consumers with interest in lucid dreaming.

These companies base their product in part on the research of neuroscientist Martin Dresler, head researcher at the Donders Sleep and Memory Lab. He and his team study lucid dreaming and have conducted many measurements of brain activity during these dreams. ‘We now suspect which brain areas are involved, including the prefrontal cortex’, Dresler explains. ‘But we still don't know exactly which structures would need to be stimulated to induce a lucid dream, or if this would even be possible with a headband.’ In other words, the futuristic plans and timelines of such neurotech companies seem very ambitious at the moment.


Dresler himself also induces lucid dreaming states in people. Not for fun, but for research purposes. He stimulates different senses of voluntary test subjects while they're awake, using light, sound, or vibrations, and asks them to focus their awareness on these stimuli and on their current state of mind in general. Then he provides the same signals during REM sleep. As a result, study participants  might recognize these stimuli while being within a dream and realize: I'm actually dreaming.

In this way, Dresler and his team get about half of their volunteers to experience a lucid dream. Most such instances of dream lucidity only lasts briefly, rarely longer than a minute or so. ‘Lucid dreaming is quite unstable’, Dresler says. ‘The brain doesn't seem to like being in this state. It quickly switches back to a normal dream or to wakefulness. In a sense, lucid dreaming might be seen as something going wrong during a regular dream.’

Math Problems

Dresler's research primarily aims to uncover what happens in the brain during sleep. And lucid dreams are a useful tool for that. ‘Creating a window into the brain during ongoing sleep allows us to learn more about the functions of sleep and dreaming, such as the role of sleep in memory consolidation’, Dresler explains.

He has already demonstrated that it's possible to make contact and communicate with someone in REM sleep. For example, he had volunteers answer yes or no questions and solve simple math problems, like eight minus six, during sleep. Lucid dreamers answered these questions using eye movements predetermined beforehand. It didn't work with all participants, but about forty percent succeeded. ‘With this research, we showed that communication with sleeping volunteers is possible in both directions, from the researcher to the sleeper and back.’


Is it a good idea to make people so active during their sleep and essentially hack their dreams? ‘We believe that normal dreams serve a biological function’, Dresler says. ‘Dreams provide us with a virtual environment where we can practice how to deal with  threats or social situations. However to fulfil this function, we likely have to take the dream seriously, and that might not be possible once we realize that we are dreaming. In this regard, it could be harmful if all our dreams were lucid. But for now, lucid dreams make up only a very small fraction of sleep even in frequent lucid dreamers, which is very unlikely to be harmful.’

Additionally, Dresler sees possibilities for medical applications of lucid dreaming. ‘There are indications that lucid dreaming can help patients with nightmare disorder. With lucid dreaming therapy, patients can realize during a nightmare that the monster that is chasing them isn't real, and might even gain some active control over the nightmare. Or they can decide to wake up if the dream isn't pleasant.’ This opens up possibilities for lucid dream directors to remove horror films from their repertoire.


Sleeping Less?

Historical anecdotes suggest that some famous individuals, such as Leonardo da Vinci and Nikola Tesla, slept polyphasically. They aimed to function well with much less sleep, for instance by sleeping six times for twenty minutes each, totaling only two hours a day. Dresler found ten motivated volunteers willing to test such a radically polyphasic sleep restriction. Most dropped out after a few days, however one participant stayed on the polyphasic rhythm for five weeks. What was found? He functioned remarkably normal and performed well on brain tests. But his body completely stopped producing growth hormone. And that is crucial for the body; ensuring healthy bones and muscles. Hence, such short naps without any extended sleep period do not seem to be a good idea.

Clearing Waste During Sleep?

Especially during deep sleep, the brain clears out various toxins that accumulate during the day. If this process doesn't work well, these toxins accumulate and can cause brain diseases like Alzheimer's. Dresler and his research team are investigating if they can stimulate this deep sleep with sound waves and whether that leads to better brain cleanup. The study has just begun.

Learning More During Sleep?

Over the last decade, many studies have shown that memory can be enhanced during sleep. Here's how: a person who is awake learns something, like an interesting fact, with a specific sound in the background. If you then play that same sound during sleep, the brain reprocesses the learned information. This helps to consolidate the information better in memory than if you hadn't reactivated the brain. Dresler and his team are now investigating, in a large study, the role of dreams in this learning process and whether dream content contributes to this memory function of sleep.


This article appeared before in Radbode #2 in 2024.

Would you like to learn more about this topic? Read this review in Neuron: The neuroscience of lucid dreaming: Past, present, future. Paul Zerr, Nico Adelhöfer, Martin Dresler.

More information

Annemarie Eek


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