How virtual reality can unlock an elusive dream state

On a nightly basis, we surrender to the whim of our minds as they weave fantastical (and sometimes, terrifying) dreams for us. Yet, despite logically knowing that ice cream cones are not self-multiplying, we often don't realize the falseness of these dreamscapes until after we've left them.

But what if you could recognize — and take control of — these dreams while still asleep? That's the concept behind lucid dreaming, a rare occurrence when dreamers realize they're in a dream and take back the reins.

In a new study, sleep researchers found an unexpected connection between virtual reality — specifically the ill-effects of too much time spent in VR — and lucid dreaming, suggesting virtual reality may be able to train the brain to dream in a totally different way.

The results were published Monday in the journal Philosophical Transactions of the Royal Society B.

The big idea — Hacking your dreams is not a new idea. In fact, there is already a well-established method for training your brain to stimulate lucid dreaming. Essentially, dreamers are encouraged throughout their waking day to occasionally stop and ask themselves: "Is this a dream?"

It sounds simple. But while this "self-induced existential crisis" may seem like an exercise in futility, the idea is that having this internal question-answer session frequently while awake may subconsciously cue your brain to ask itself the same question when you're sleeping, too. And voila: A lucid dream begins.

But this method doesn't work for everybody — not least because continuously reminding yourself to ask whether you are dreaming may feel repetitive at best, maddening at worst. But virtual reality could train our brains better, the researchers theorized.

"Since waking life rarely contains dream-like or surreal moments, the provision of these environments via VR would be one way to increase the availability of convincingly dream-like experiences; within which a moment for genuine critical reflection is made available. Thus, the traditional method for lucid dream induction—critical questions about one’s current state of mind and ‘reality checks’ — may be greatly enhanced through the additional provision of VR environments with dream-like aesthetic properties."

What they did — In their trial, the researchers compared the benefits of a virtual-reality training program, traditional lucid-dream training, and zero training to see what effect the different approaches would have on one's ability to lucid dream.

The researchers divided 39 participants into three trial groups, one for each style of training being evaluated. It is important to note the virtual-reality training group also participated in aspects of traditional training, but the traditional training group did not participate in any virtual-reality training.

They then tasked all participants with keeping dream journals over a six-week period. The participants in the virtual-reality group and the traditional training group also participated in certain additional activities during four of those weeks.

They were asked to perform "reality checks" on themselves 5-10 times per day by asking themselves questions like: "Am I dreaming?" They logged their check-ins on their phones.

The virtual-reality group also participated in 12 virtual-reality sessions over the course of the four weeks. During these sessions, participants started in fairly mundane environments — as a waiter in a university lunchroom, say. But over time, these environments becoming increasingly unrealistic — for example, "customers" in the lunchroom might turn into mannequins, or gravity would fail.

In the first and last week of the trial, the participants underwent a polysomnography study, in which their brain waves, oxygen levels, and blood flow were measured as they slept. To signal to researchers they were experiencing a lucid dream during these studies, participants were asked to move their eyes left-to-right.

What they discovered — The research team found participants who underwent virtual-reality training were able to have lucid dreams more often than non-trained dreamers, suggesting virtual reality may provide an ideal environment for training the brain to access this elusive kind of dreaming.

But importantly, traditional training appeared to be just as effective as the virtual-reality training, according to the study.

What's new — In some ways, the study poses more questions about lucid dreaming than it answers. Ultimately, the researchers say their mixed results may be to do with how rare the lucid-dream experience is, even if you are actively trying to induce this dream state.

But when looking more closely at the virtual-reality group, the researchers find a connection between an unpleasant side-effect of virtual reality and lucid dreams. Characterized by nausea and feelings of dissociation, "VR sickness," as it is known, may be playing a role in how the technology stimulates lucid dreaming.

Several participants reported moderate feelings of dissociation for up to two hours after virtual-reality training. The researchers believe these feelings may have made these participants' "reality checks" even more effective prompts for their brains.

"It could accordingly be argued that dissociative symptoms related to VR might instill a sense of ‘dissreality’ and ‘reality skepticism’ that increased the authenticity of reality checks. In other words: it could well have been a potential post-VR dissociative state that was ‘dream like’, rather than the VR content itself."

Essentially, "VR sickness" made participants more likely to question their reality anyway, which may have made their deliberate self-questioning more effective. The researchers also note that dreaming about virtual reality itself — and then in turn remembering they are part of a study — may have also contributed to virtual reality's seeming effect on lucid dreaming.

What's next — More work is needed to investigate the potential mechanisms for virtual-reality inspired lucid dreaming. One outstanding question is how much effect they really have on the dreamer, these researchers point out. Future studies could also control and measure the levels of dissociation experienced by participants to better understand why some participants go on to experience lucid dreaming, while others do not, the researchers say.

Abstract: Metacognitive reflections on one’s current state of mind are largely absent during dreaming. Lucid dreaming as the exception to this rule is a rare phenomenon; however, its occurrence can be facilitated through cognitive training. A central idea of respective training strategies is to regularly question one’s phenomenal experience: is the currently experienced world real, or just a dream? Here, we tested if such lucid dreaming training can be enhanced with dream-like virtual reality (VR): over the course of four weeks, volunteers underwent lucid dreaming training in VR scenarios comprising dream-like elements, classical lucid dreaming training or no training. We found that VR-assisted training led to significantly stronger increases in lucid dreaming compared to the no-training condition. Eye signal-verified lucid dreams during polysomnography supported behavioural results. We discuss the potential mechanisms underlying these findings, in particular the role of synthetic dream-like experiences, incorporation of VR content in dream imagery serving as memory cues, and extended dissociative effects of VR session on subsequent experiences that might amplify lucid dreaming training during wakefulness. This article is part of the theme issue ‘Offline perception: voluntary and spontaneous perceptual experiences without matching external stimulation’.