Dreams are shaped by both stable individual traits and major external events. A large adult cohort provided dream and wakefulness reports alongside demographic, psychometric, cognitive, and sleep measures. Natural language processing revealed semantic features that distinguish dream from wakefulness reports, with this distinction significantly modulated by individual-specific factors. Longitudinal and cross-sample analyses showed that the COVID-19 pandemic left lasting traces on dream content. The findings highlight a dynamic interplay between personal characteristics and external events in shaping dream experiences, offering insights into the cognitive and emotional architecture of dreaming.
Dreams are universal yet highly personal. By analyzing 3,366 reports of dreams and waking experiences from 207 adults collected between 2020 and 2024, along with demographic, cognitive, psychometric, and sleep measures, researchers found that dreams differ from waking thoughts: they are less self-referential and thought-centered, and more perceptual, dominated by visuo-spatial details, multiple characters, and bizarre events. Stable traits like attitude toward dreaming, mind-wandering propensity, and subjective sleep quality selectively influenced dream content. During the first 2020 COVID-19 lockdown, dreams from an independent dataset of 80 participants showed increased references to limitations and heightened emotional intensity, which gradually normalized over subsequent years. Stable individual traits and incidental experiences jointly shape dream semantics.
Two methods for measuring brain connectivity, wPLI and wSMI, detect different types of neural interactions. Using simulated EEG data, wPLI is sensitive to couplings that mix linear and nonlinear dependencies, while only wSMI detects purely nonlinear interactions. In real EEG recordings from 12 healthy adults during wakefulness and deep sleep, both methods showed different sensitivity to changes in brain connectivity across these states. The findings suggest that using both methods together provides a more complete picture of the functional basis of consciousness in both healthy and altered states.