Harnessing the cognitive and neurophysiological processes characterising the sleep onset period

Introduction

Sleep often escapes us when we need it or intrudes when we would prefer to stay awake. What if we could control when we fall asleep? While our understanding of sleep has rapidly grown, what happens during the wake to sleep transition remains mysterious, potentially due to the widespread assumption that we are either awake or asleep.

Current Understanding of Sleep States

The current standard is to define vigilance states through coarse, physiological criteria that are visually assessed on fixed, 30s epochs. In this framework, the sleep onset period (SOP) typically corresponds to the first sleep stage. Yet, this classification in discrete sleep stages fails to account for the gradual, dynamic changes observed in the descent to sleep, on the:

• Behavioral level (reduced responsiveness to stimuli)
• Subjective level (dream-like experiences called hypnagogia)
• Cognitive level (decline in executive functions, enhanced creativity)

Research Proposal

To better understand how we transition from full vigilance to sleep, I propose to integrate, within the same framework, the many dimensions of the sleep onset process.

Hypothesis

I hypothesize that the behavioral, subjective, and cognitive changes associated with the SOP are each reflected by specific neurophysiological signatures that are partially independent of sleep stages.

Preliminary Findings

I recently found candidate physiological markers for the different SOP dimensions. In CREADOZE, I will leverage these findings to refine in space and time the neurophysiological signatures reflecting the processes which decline (behavioral responsiveness, executive abilities) and those which emerge (hypnagogia, creativity) during the SOP, using multimodal physiological recordings.

Exploration of Markers

I will explore how these markers fluctuate in relation to each other and identify potential factors influencing them, such as:

1. Sleep pressure
2. Sleep disorders

Neurofeedback Training

Then, I will use neurofeedback to train individuals to either resist or embrace sleep. If successful, this proposal will open the possibility to harness the sleep onset period depending on one’s needs.