Why do we dream? Evolutionary theories suggest that dreams may confer a fitness advantage by simulating real-world challenges. Simulation-based models suggest that dreams serve adaptive functions, including resolving emotional stress and enhancing readiness for waking encounters. From this perspective, evidence of evolutionary pressures reflected in dream content would support the view that...
According to some theories of emotion regulation, dreams could modify negative emotions and ultimately reduce their intensity. We introduce here the idea of cathartic dream, a specific and separate type of emotional dream, which is characterized by a dynamic plot with emotional twists, and where negative emotions are expressed and ultimately decreased. This process would reflect psychological...
The function of dreams is a longstanding scientific research question. Simulation theories of dream function, which are based on the premise that dreams represent evolutionary past selective pressures and fitness improvement through modified states of consciousness, have yet to be tested in cross-cultural populations that include small-scale forager societies. Here, we analyze dream content...
The waking brain efficiently detects emotional signals to promote survival. However, emotion detection during sleep is poorly understood and may be influenced by individual sleep characteristics or neural reactivity. Notably, dream recall frequency has been associated with stimulus reactivity during sleep, with enhanced stimulus-driven responses in high vs. low recallers. Using...
Summary: Functional dissociations in the brain observed during non-rapid eye movement (NREM) sleep have been associated with reduced information integration and impaired consciousness that accompany increasing sleep depth. Here, we explored the dynamical properties of large-scale functional brain networks derived from transient brain activity using functional magnetic resonance imaging. Spatial...
Ketamine has been documented for its rapid antidepressant effects. However, optimal dose and delivery route have not yet been thoroughly investigated. The objectives of this study were to document the safety and test the antidepressant and antisuicidal effects of a single rapid 1-minute injection of ketamine 0.5 mg/kg in treatment-resistant depression (TRD). Ten patients with TRD were included...
Dream is a state of consciousness characterized by internally-generated sensory, cognitive and emotional experiences occurring during sleep. Dream reports tend to be particularly abundant, with complex, emotional, and perceptually vivid experiences after awakenings from rapid eye movement (REM) sleep. This is why our current knowledge of the cerebral correlates of dreaming, mainly derives from...
Our neurobiological knowledge about human dream organisation results primarily from the study of Rapid-Eye-Movement (REM) sleep.In humans, functional neuroimaging techniques, using H 2 15 O or 18 FDG positron emission tomography (PET) and functional magnetic resonance imaging (fMRI), allowed the mapping of the regional cerebral activity during this sleep stage, which is dominated by the...
In this chapter, we aimed at further characterizing the functional neuroanatomy of the human rapid eye movement (REM) sleep at the population level. We carried out a meta-analysis of a large dataset of positron emission tomography (PET) scans acquired during wakefulness, slow wave sleep and REM sleep, and focused especially on the brain areas in which the activity diminishes during REM sleep....