Biology subjects

Elce, V.

Publications and source records attributed to Elce, V..

4 recordsLinked to original sources

bioRxiv2025

Immersive NREM dreaming preserves subjective sleep depth against declining sleep pressure

Perceived sleep depth is a key determinant of subjective sleep quality, traditionally thought to reflect unconsciousness and reduced cortical activation. Here, we combined high-density EEG with a serial awakening paradigm during NREM sleep to examine its neural and experiential correlates. As expected, deeper sleep was associated with reduced cortical activation, reflected in a lower high-to-low frequency power ratio. Yet, this relationship weakened in the presence of dreaming, indicating that immersive conscious experiences can counteract the impact of cortical activation on perceived depth. Indeed, perceived sleep depth was lowest during states with a mere sense of presence and highest during immersive dreaming or deep unconsciousness. Across the night, physiological sleep pressure and subjective sleepiness declined, but perceived sleep depth rose alongside increasing dream immersiveness. These results challenge the view that deep sleep stems solely from reduced brain activity and suggest that immersive dreaming sustains perceived sleep depth as homeostatic pressure wanes.

neuroscience↗

bioRxiv2025

Nightly dynamics of emotional content in dreams

Emotional processing is a crucial adaptive function. Research suggests that sleep, particularly rapid eye movement (REM) sleep, may have a role in processing the emotional load of past events. Notably, dream experiences may offer insight into this nighttime process. Some studies have reported increased emotionality in dreams as the night progresses, possibly reflecting ongoing emotional processing in the sleeping brain. However, findings on how dream affect evolves throughout the night remain mixed. In this study, we investigated how emotional intensity in conscious experiences during sleep changes across the night and sleep stages. Participants (Nsubjects = 20) were subjected to a multiple awakening paradigm, where they were awakened 4-5 times throughout the night and asked to recall their dreams (Ndreams = 61). Additionally, they rated the emotional intensity of their experiences using a structured cued questionnaire. Emotional intensity in dreams increased significantly throughout the night, with late-night dreams being more emotional than dreams collected during earlier sleep. Contrary to our expectation, this increase was not driven by dream reports obtained from REM sleep awakenings. Moreover, late- night dream reports were also significantly longer than those from early sleep, yet the length of the dream reports did not correlate with their emotional intensity. This suggests that the emotionality of dreams is not directly linked to the ability to recall the dream or its narrative complexity. Instead, it could be driven by emotional processes occurring independently throughout the night, or by other factors that regulate our access to dream experiences and their emotional content.

neuroscience↗

bioRxiv2025

The semantics of dreams

Dreams are universal yet deeply personal experiences. While memory and personal concerns influence dream content, the impact of other individual, generalizable traits remains poorly understood. To address this gap, we built a multimodal dataset including dream and wakefulness reports, alongside demographic, psychometric, cognitive, and sleep-related measures in a large adult cohort. Natural language processing characterized the semantic features that quantitatively distinguish dream from wakefulness reports, with this distinction significantly modulated by individual-specific factors. Longitudinal and cross-sample analyses further demonstrated that major external events, such as the COVID-19 pandemic, affect dream content, leaving lasting traces. Overall, the findings highlight a dynamic interplay between stable individual traits and external events in shaping dream experiences, offering novel insights into the cognitive and emotional architecture of dreaming.

neuroscience↗

bioRxiv2024

The individual determinants of morning dream recall

Evidence suggests that (almost) everyone dreams during their sleep and may actually do so for a large part of the night. Yet, dream recall shows large interindividual variability. Understanding the factors that influence dream recall is crucial for advancing our knowledge regarding dreams origin, significance, and functions. Here, we tackled this issue by prospectively collecting dream reports along with demographic information and psychometric, cognitive, actigraphic, and electroencephalographic measures in 204 healthy adults (18-70 y, 113 females). We found that attitude towards dreaming, proneness to mind wandering, and sleep patterns are associated with the probability of reporting a dream upon morning awakening. The likelihood of recalling dream content was predicted by age and vulnerability to interference. Moreover, dream recall appeared to be influenced by night-by-night changes in sleep patterns and showed seasonal fluctuations. Our results provide an account for previous observations regarding inter- and intra-individual variability in morning dream recall.

neuroscience↗