Our brains use a complex mix of internal clocks and chemical signals to decide when it’s time to sleep, wake, and dream.•The circadian rhythm is like an internal 24-hour clock controlled by a brain area called the suprachiasmatic nucleus. It responds to light and darkness, telling us when to feel sleepy or alert.
•Meanwhile, as we stay awake the brain builds up chemicals like adenosine that increase “sleep pressure” the more pressure the more tired we feel until it’s time to sleep.
•Dreaming mainly happens during REM sleep, which cycles every 90 minutes or so and is controlled by brainstem regions. Dreaming isn’t a conscious choice but part of this sleep phase.
•Interestingly, some animals and people can function with very little dreaming, so it’s not absolutely necessary for survival but it probably helps with memory, emotions, and creativity.
•This balance between internal clocks, chemical buildup, and brain cycles controls our sleep and dreaming patterns but many details about how and why this all happens remain mysterious.What do you think? How do you notice your body managing sleep and dreams, especially during things like jet lag or naps?