Understanding and Controlling Sleep: The Dream of Delphine Oudiette

In the past, Delphine Oudiette dreamt of becoming an explorer, journalist, philosopher, or perfume creator. Today, she is a scientist in the field of dreams and has recently obtained European Research Council (ERC) funding in order to explore the process of falling asleep. Knowing more about this poorly-understood phase of transition between wakefulness and sleep could bring new insights into the treatment of sleep disorders. It could even help improve the processes of learning and creativity.

Delphine Oudiette, Brain Institut (unit 1127 Inserm/CNRS/Sorbonne Université)

« In our contemporary societies, epidemics of insomnia and drowsiness coexist. Although the process of falling asleep is common to both issues, it has been very much underexplored by clinicians and scientists,” notes Delphine Oudiette, a trained biologist who specializes in cognitive neuroscience. The researcher devotes her career to studying the brain processes that occur during sleep. She has just obtained European funding of 2 million euros over 5 years to explore that particular period of transition between wakefulness and sleep: a phase that is favorable to semi-conscious states, conducive to wandering and during which reality flirts with dreams.

Called Creadoze, this research project aims to explore how falling asleep differs from the waking state in terms of awareness of the outside world, and the potential for improving sleep, memorization, and creativity. Because since she has been studying dreams, Oudiette has come to the conviction that the current characterization of the sleep phases is inaccurate, or at least incomplete. « Broadly speaking, we currently divide sleep into phases whose boundaries are delineated according to characteristics measured by polysomnography examinations. » The latter,which consist of recording brain and muscle activities as well as eye movements, make it possible to distinguish between the stages of falling asleep (N1), deeper sleep (N2), deepest non-REM sleep (N3), and REM sleep. « But there’s a growing body of data to suggest that the boundaries between wakefulness and sleep are more porous than we think, » emphasizes the researcher. For example, polysomnography does not identify the precise time at which we transition from one state to the other. What is more, « some people can say they were asleep when they were ‘awake’ according to the standard classification, and many argue that they were awake when they were technically ‘asleep’. Finally, we know that it’s possible to respond to external stimuli during N1 and N2 without waking up. » This disconnect between the subjective feeling of sleeping, the capacity to respond to the outside world and the recordings of brain activity therefore calls into question the current sleep classification.

Learning How to Identify and Control the Transition From Wakefulness to Sleep

With Creadoze, the researcher wants to identify markers of brain activity in order to better characterize the period of falling asleep. « We could not only improve the knowledge and precise classification of the different states of alertness, but these elements could also help us to advance in the management of sleep disorders: if it’s possible to identify brain signals that indicate how close we are to transitioning to sleep or, on the contrary, that of a return to a waking state, it must be possible to learn how to detect and control them. » Thus, after several sessions of monitoring brain activity during which sound signals would indicate to the participant the appearance of one of these markers, he or she would gradually learn to recognize them. The participant could then be trained in how to control them, in order to resist or on the contrary accelerate the transition to sleep, depending on his or her needs.

The same principle could be used to boost creativity and learning. Indeed, in previous studies, Oudiette and her team described that people who took a few minutes’ nap after being presented with a mathematical enigma tripled their chances of resolving it on waking, compared to those who had fallen into prolonged sleep or who had remained awake. « So, falling asleep is a phase conducive to creativity that we could use on a daily basis if the results of Creadoze allow us to characterize the brain mechanisms involved. » But much remains to be understood.

Liberty, Curiosity, Inventiveness

As a child, Oudiette saw herself becoming an explorer or an archaeologist to « discover, investigate, solve enigmas, » or as a « nose » to create fragrances. Not surprising then that sleep, which continues to remain so mysterious, has become her preferred field. At the end of high school, passionate about writing and brimming with existential questions, Oudiette was more attracted by philosophy. But it was a memorable visit to the Gallery of Evolution in Paris that set her on the path of biology: « I felt that this discipline could answer many of the questions I had and lead me to a less solitary and more creative career than philosophy, » she explains. She then turned towards neuroscience, with the idea of becoming a scientific journalist to combine her taste for writing and her knowledge of biology. After a few disappointing internships in editorial offices, she understood that it was scientific research that could bring her what she enjoys: making hypotheses, searching for truth, and telling a story.

It was during her first Masters internship in the laboratory of Isabelle Arnulf, neurologist at Pitié-Salpêtrière hospital and researcher at the Brain Institute (ICM) in Paris, that Oudiette took her first steps in the field of sleep. It was there that she went on to do a PhD on the characterization of the sleep of patients with behavioral disorders during REM, who externalize their dreams and adopt sometimes violent behaviors. After a stint in the U.S. where she studied the reactivation of memories during sleep, she returned to the Brain Institute and focused on the case of lucid dreamers, individuals who are aware that they are dreaming while they are doing so and, for some, are able to influence the scenario of their dreams. Since then, she has remained with Inserm and is now a research officer.

Creadoze will officially launch in October 2023 and its European funding will make it possible to hire a team of five researchers and fund numerous experiments. At the head of this team, Oudiette will be able to focus on what she prefers today: « The intellectual and human aspects of the role of mentor suit me much better than the research activity itself. As a PhD student, I felt frustrated spending so much time on collecting data because what I wanted to do first and foremost was to devise experimental concepts and designs, and to understand and interpret the results. But today I’m very content: I’m following the projects of several students simultaneously, supporting them according to their needs, encouraging them in developing their autonomy and freedom – a vector of inventiveness. Sleep is an ideal area for this because there is still little consensus and therefore a lot of leeway to explore and understand, concludes theresearcher. Finding a way to better manage sleep and harness its cognitive potential – now that would be the dream! »

Delphine Oudiette is an Inserm researcher on the Mov’It team at the Brain Institute (unit 1127 Inserm/CNRS/Sorbonne Université) and the sleep disorders department at Pitié-Salpêtrière hospital in Paris. In 2024, she will co-lead the DreamTeam, which is currently being formed, with Isabelle Arnulf.

Author: C. G.