Long TextExercise 72 of 81

For most of human history, sleep was understood as a passage - a nightly migration from the waking world into a realm that, while mysterious, was no less real and no less consequential than the daylit landscape the sleeper had left behind. Dreams were omens, visitations, or voyages; the sleeping body was a vessel…

• How did pre-modern cultures generally understand the nature of sleep?
• What did early electroencephalography reveal about the sleeping brain?