REM sleep is distinct from sleep’s other stages, and is sometimes referred to as paradoxical sleep. During phases of Non-REM sleep, brain activity slows and changes considerably from its waking state. In REM sleep, the brain becomes highly active. During phases of REM, the brain functions at levels similar to that of a waking brain. At times, levels of brain activity of REM can actually be higher than when you are awake. Heart rate and breathing also increase and become more variable, compared to other stages of sleep. REM stands for Rapid Eye Movement, one of the most marked physical characteristics of this sleep phase. During REM sleep, the eyes move back and forth constantly underneath closed lids.
How much time in REM?
Over the course of a night, you spend approximately 25 percent of sleep in REM phase. REM sleep doesn’t occur all at once. Instead, periods of REM are interspersed among the other stages of sleep as you move through a series of sleep cycles. It typically takes about 90 minutes of sleep to arrive at the first REM period. The first stop of the night in REM sleep is brief, lasting roughly five minutes. Each subsequent return to REM grows longer. REM sleep is predominant in the final third of the night, and the final stage of REM sleep can last 30 minutes. A full night of sleep—typically in the range of seven to nine hours—is necessary to achieve all the restorative benefits of REM sleep.
What is REM atonia?
While the brain is very active during REM sleep, the body is largely immobilized. In REM sleep, a temporary paralysis occurs, known as REM atonia. This immobilization protects the body, preventing the sleeper from acting out physically in response to dreams. It’s possible to wake from this phase of sleep while unable to move or to speak, a phenomenon called sleep paralysis. The effects of sleep paralysis are fleeting, and typically last only a few seconds or minutes. Still, this can be a frightening experience. If you find yourself waking under these conditions, do your best not to panic. Stay relaxed and allow your brain and body to come back into sync.
A time for mental recharge
REM sleep is a phase that’s closely linked with mental recharge. During its time in REM throughout the night, your brain refreshes and restores itself. This is one reason why REM sleep is so important, and why a healthy sleep routine with sufficient amounts of REM sleep is essential to feeling mentally and emotionally well, and to performing at your best during your waking life.
REM sleep is believed to play an important role in learning, memory, and emotion. It is often thought of as the sleep phase during which the brain restores itself. The areas of the brain that are most active during REM sleep are those related to thinking, learning, and decision-making, as well as to emotional regulation. REM sleep is linked to the brain’s ability to make new associations, aiding in the acquisition of new information, problem solving, and creativity. Research indicates REM may play an important role in some forms of memory consolidation, the process by which brain converts newly acquired information into longer-term memory. Evidence also suggests that during REM sleep the brain is at work processing emotions, helping to regulate mood.
The dreaming stage of sleep
Most dreaming occurs during REM sleep. On average, you will spend about two hours per night dreaming. Often those dreams aren’t remembered. If you wake from REM sleep, you’re more likely to recall that you’ve been dreaming.
Dreaming is one of the great mysteries of the human experience, and of sleep itself. Humans have long wondered about the meaning and purpose of dreams, and cultures have connected dreams to their deepest hopes and fears. Many ancient cultures saw dreams as messages, often warnings, from the gods. Throughout history, dreams have been regarded as out-of-body explorations for the soul, as a means to communicate with the dead, and as harbingers of “evil” spirits. Sigmund Freud theorized dreams as a landscape in which to explore the repressed emotions and desires of the unconscious mind. Carl Jung also saw dreaming as a view to the unconscious, but believed dreams manifested the fears and emotions left un-tended in our waking lives.
Why do we dream?
Dreaming remains a scientific mystery even today. Contemporary investigations of dreaming include exploration of both psychological and neurological functions. Theories of the purpose of dreaming continue to cover wide terrain, and often overlap with one another. Some theories posit that dreams are means to integrate new experiences into memory, and to process emotional and traumatic events as a way to regulate mood. Other theories suggest dreaming is the brain’s way of de-cluttering itself after a long, active day of acquiring new information. Some scientists think dreams are a response to stimuli gathered throughout the day, while others contend that dreams are a response to the external stimuli that occurs during sleep itself. Another theory suggests that dreams are the brain’s way of making sense of the electrical impulses that occurs during the brain’s very active REM phase.
The right amount of REM
As with all stages of sleep in your sleep cycle, REM sleep is about balance. Too much and too little REM sleep can have negative consequences for your mood, your alertness and ability to focus, and your capacity to take in new information. There are several factors that can disrupt healthy levels of REM. Alcohol consumption too close to bedtime diminishes time spent in REM sleep. Stress, on the other hand, can extend REM sleep beyond normal levels. Too much REM sleep can actually leave you feeling tired the next day. Ensuring a full night of high-quality rest will help you receive all the benefits of this highly restorative sleep phase.