Sleep

Main

Sleep is a state of reduced mental and physical activity where consciousness is altered and sensory activity is inhibited. It is a vital process that helps restore the immune, nervous, skeletal and muscular systems. Sleep occurs in repeating periods, alternating between two distinct modes: REM (rapid eye movement) and non-REM sleep.

During sleep, several processes occur:

1. Memory consolidation: Sleep helps transfer short-term memories into long-term storage, strengthening neural connections and facilitating learning.

2. Hormone regulation: Sleep helps regulate the release of hormones such as growth hormone (which promotes growth and development), cortisol (which helps manage stress), and melatonin (which regulates sleep-wake cycles).

3. Cellular repair: During sleep, the body increases production of proteins that help repair and regenerate cells, tissues, and organs, including the skin, muscles, and brain.

4. Brain cleansing: During sleep, the brain's glymphatic system clears out toxins, such as beta-amyloid, that accumulate during wakefulness and are associated with neurodegenerative diseases.

5. Body temperature drop: Core body temperature decreases during sleep, particularly during non-REM stages, which helps conserve energy and promote restorative processes.

Terms

• Circadian clock: The internal process that regulates the sleep-wake cycle.

• REM sleep: A stage of sleep characterized by rapid eye movements, vivid dreams, and increased brain activity.

• Non-REM sleep: Stages of sleep that occur before REM sleep, including light and deep sleep stages.

Analogy

Sleep is like plugging in your phone to charge overnight. Just as your phone receives a power boost and installs necessary updates, sleep allows your body and mind to recharge, repair, and consolidate memories. Without this nightly maintenance, your phone's performance may suffer, just as lack of sleep can impair your cognitive function and overall health.

Misconception

A common misconception is that you can "catch up" on missed sleep by sleeping longer on weekends. However, depending on how sleep-deprived you are, extra weekend sleep may not be adequate to make up the deficit. Consistently getting enough sleep each night is important.

History

1. 1937 - Discovery of the human EEG and its application to sleep research

2. 1953 - REM sleep first described

3. 1970s - Further research into the stages and functions of sleep

4. 2000s - Increasing recognition of the impact of artificial light and electronic devices on sleep patterns

How to use it

1. Stick to a consistent sleep schedule, going to bed and waking up at the same times each day. Expose yourself to sunlight early in the morning and in the evening to help set your circadian rhythm.

2. Create a relaxing bedtime routine, such as taking a warm bath or reading before bed.

3. Ensure your bedroom is quiet, dark, and at a comfortable temperature. Avoid bright lights and loud sounds. Don't watch TV or use electronic devices in bed.

Facts

• The world record for the longest time without sleep is 11 days and 25 minutes, held by Randy Gardner in 1964.

• Giraffes only sleep for about 30 minutes a day in short naps.

• Blind people can still perceive light through their retinas, which helps regulate their sleep-wake cycles.

• The sensation of falling that sometimes occurs just as you're drifting off to sleep is called a "hypnic jerk."

• 12% of people dream in black and white.