You have likely heard of lucid dreaming. Perhaps you have even had a lucid dream yourself. In case you are uncertain, a lucid dream is a dream in which the dreamer is aware that they are dreaming .
Because the dreamer is aware that what they are experiencing is not reality, they can sometimes then control what happens in their dream.
Researchers from MIT have now taken the idea of lucid dreaming a step further. In an Inception-style fashion, they have developed an experimental device and protocol to manipulate the content of people’s dreams while they are dreaming .
By making participants recall specific cues that can trigger targeted dream themes and experiences, a research team at MIT has managed to control what happens in their dreams.
The team, which was led by neuroscientist Adam Haar Horowitz, took advantage of a state of consciousness known as hypnagogia, which is the fluid first stage of sleep. This stage differs from REM sleep in that people can still hear and process audio as they transition between being awake and being asleep or vice-versa.
Horowitz describes that state of mind as “tippy, loose, flexible, and divergent”.
“It’s like turning the notch up high on mind-wandering and making it immersive — being pushed and pulled with new sensations like your body floating and falling, with your thoughts quickly snapping in and out of control.” 
During this lucid state of mind, the researchers are able to induce “targeted dream incubation (TDI)” using a wearable device called Dormio, which is a sleep-tracking device that can alter dreams by tracking hypnagogia, then introduce cues based on incoming physiological data at precise times throughout the sleep cycle to enable them to direct the content of dreams .
“Dormio takes dream research to a new level, interacting directly with an individual’s dreaming brain and manipulating the actual content of their dreams,” says Robert Stickgold, director of the Center for Sleep and Cognition at Beth Israel Deaconess Medical Center and professor of psychiatry at Harvard Medical School .
To Dream of a Tree
The team’s first pilot study was conducted in 2018 using six participants. Since then, they have conducted a larger study with fifty participants that has replicated and extended the results of the initial study.
So how does the protocol work? In the larger experiment, participants fell asleep while wearing the Dormio device. During this time, audio cues such as “remember to think of a tree” were played via an associated app.
The Dormio device tracks physiological data that signals when the person has fallen asleep. When this happens, the system briefly wakes them up and asks them to say what was going through their mind as they slept, and the app records their verbal dream report .
This TDI process is continued during a series of repeated dreams, awakenings, and prompted recordings, all which, in theory, center around a state of directed hypnagogia .
“Targeted dream incubation is a protocol for reactivating memories during sleep in a manner that leads to incorporation of the targeted memory, or related memories, into dream content,” the researchers explained .
The goal of the study was to assess whether or not Dormio could successfully identify the sleep onset period and if researchers could manipulate dream content through pre-sleep verbal prompts. While the prototype system is still being refined, the results show that Dormio can influence dreams to a significant extent.
When Dormio prompted the participants to think of a tree before and during hypnagogia, 67 percent of the dream reports collected by the app mentioned a tree. One participant described their dream upon waking:
“I was following the roots with someone and the roots were transporting me to different locations… I could hear the roots of the tree pulsating with energy as if they were leading me to some location.” 
A control group, on the other hand, showed almost no references to a tree. The participants in this group were not prompted to think of a tree, only to observe their thoughts.
Application of Dream Incubation
The team believes that Dormio and TDI protocols can shed light on the role of dreams in the overnight transformation of experiences into memories . This can then be used for a variety of learning techniques that involve sleep-based memory consolidation, or a tool to improve creativity and problem-solving.
“Dreaming about a specific theme seems to offer benefits post-sleep, such as on creativity tasks related to this theme,” Haar Horowitz says.
He points to historical figures like Mary Shelley or Salvador Dalí, who both found creative inspiration from their dreams.
“The difference here is that we induce these creatively beneficial dreams on purpose, in a targeted manner.” 
In addition, the nature of this new device and protocol will make studying sleep and dreams easier for researchers and participants.
“Most sleep and dream studies have so far been limited to university sleep labs and have been very expensive, as well as cumbersome, for both researchers and participants,” says professor of media arts and sciences Pattie Maes. “Our research group is excited to be pioneering new, compact, and cheap technologies for studying sleep and interfacing with dreams, thereby opening up opportunities for more studies to happen and for these experiments to take place in natural settings.” 
This work could lead to new innovations in commercial technologies to address sleep onset, sleep quality, sleep-based memory consolidation, and learning.
A number of other universities have begun their own studies related to Dormio, and the team is also leading collaborations with artists, using dreams to augment artistic creativity.