Variability in how people perceive the same sensory stimulus from one moment to the next may stem from ongoing fluctuations in baseline brain activity. This review examines evidence that activity levels in sensory brain areas before a stimulus predict whether that stimulus will be consciously perceived. The findings are discussed in the context of recent discoveries about the structure of spontaneous BOLD signal fluctuations in the awake human brain, and possible sources of these baseline fluctuations are considered.
Lucid dreaming occurs when a person realizes they are dreaming while still asleep, often involving vivid images and unusual bodily sensations like flying. A new multicomponent framework proposes that lucid dreaming arises from prediction error signals during sleep, which are resolved by creating a superordinate self-model that integrates ambiguous sensory inputs from both the body and higher brain regions. Multisensory integration maintains lucidity and contributes to kinesthetic experiences, while attentional control balances top-down mental models and bottom-up sensory precision. This framework links neural correlates of lucid dreaming to sleep and arousal regulation, generating testable predictions about individual differences and neurocognitive mechanisms that induce lucid dreams.