Sensory Disconnection and Dreaming: The Functional and Phenomenological Impact of Sensory Stimulation During Sleep

Sleep is often perceived as a state of disconnection from the environment. Yet, accumulating evidence suggests that the brain can monitor and process external stimuli even while asleep. The accompanying subjective experiences, commonly referred to as dreams, are also thought to be influenced by sensory perceptions. However, the precise mechanisms through which sensory stimulation affects dreaming activity remain largely unknown. This work seeks to address this gap through a comprehensive, multi-faceted approach. It begins with a systematic review of the existing literature on the influence of sensory stimulation on dreams, uncovering key findings and identifying current limitations in the field. Following this, an experimental study investigates the use of multimodal sensory stimulation to enhance dream lucidity during REM sleep, highlighting the potential of sensory-based protocols for facilitating real-time communication with dreamers and objectively exploring perceptual awareness during sleep. Finally, the relationship between multimodal stimulation during NREM sleep and EEG aperiodic activity is empirically explored, indicating that aperiodic spectral slopes may serve as informative markers of subjective sleep experiences. By integrating theoretical, experimental, and analytical perspectives, this work aims to deepen the understanding of how external stimuli influence consciousness during sleep. The findings contribute to the growing body of knowledge on the dynamic interplay between the sleeping brain and sensory stimulation, offering valuable insights into how these interactions shape our dreams.