Key takeaways:Awakening follows a structured sequence in the brain: activity starts in central and frontal regions and spreads toward the back. Non-REM awakenings show a brief surge of slow waves before faster wake activity, while REM awakenings skip slow waves and transition directly into fast activity. The study, published in Current Biology, reveals that the brain doesn’t wake up all at once. When looking at the activity progression throughout the awakening brain, they observed a clear sequence: it starts in central and frontal brain regions and gradually spreads toward the back of the brain. Some slow waves are actually acting like arousal elements—they are part of the ‘wake up!’ signal.