The neurocognition of dreaming: key questions and foci.

Dreaming is closely linked to REM sleep, which features intense emotional activation, reduced frontal-lobe activity, and increased dopamine and acetylcholine—patterns that match typical dream qualities like fear, reduced reality monitoring, bizarreness, and hyperassociativity. The default mode network provides a way to understand dreaming independently of REM sleep, and electroencephalography paired with serial awakenings shows that high-frequency activity in posterior brain regions may be associated with dreaming. However, all measures of dreaming depend on recall processes, so understanding dreaming requires addressing memory's crucial role in producing dream reports.

Study at a glance

Abstract

Until recently, understanding the neurobiology of dreaming has relied upon on correlating a subjective dream report with a measure of brain activity or function sampled from a different occasion. As such, most assumptions about dreaming come from the neuroscience of rapid eye-movement (REM) sleep from which many, but not all, dream reports are recalled. Core features of REM sleep (intense emotional activation, a reduction in activity in most frontal regions, particularly the dorsolateral prefrontal cortex, along with increased dopamine, acetylcholine, cholinergic activation) align with typical dream characteristics (characterised by fear, reduced reality monitoring, increased bizarreness and hyperassociativity, respectively). The default mode network offers a way of understanding the nature of dreaming more independently from a REM sleep context, and electroencephalography methods paired with serial awakenings to elicit dream reports demonstrate how high-frequency activity in posterior regions may be associated with dreaming. Nevertheless, all measures of dreaming rely fundamentally on recall processes, so our understanding of dreaming must embrace and address memory's crucial involvement in dream report production.