Dr. Greene’s Answer:
Dreams have been described since the beginning of human history, but it was only in 1953 that Aserinsky and Kleitman discovered the brain wave pattern we call REM (rapid-eye-movement) sleep. During sleep, we go through four progressively deeper stages of sleep (stages 1 to 4) in which the brain is quiet but the body may move or shift.
In a separate stage, called REM sleep, the brain is highly active, but the body seems paralyzed (except for the eyes, which dart back and forth). This REM sleep is what we know as dreaming. As adults, we spend about 20% of our sleep time in REM sleep.
A preschool-aged child patters down the hall in the middle of the night to appear at her parent’s bedroom door. Tears streak her face. “Mom, I’ve had a bad dream!” she reports. “Robbers were chasing me!”
At age 3 or 4, most children begin remarking about their dreams. In their desire to imitate adult behavior, children at that age assert (with confidence) many things that aren’t quite factual. Are they really having dreams? Or might they be using their fertile imaginations to describe what they’ve heard others talk about, perhaps as yet another way to try to maneuver into the parents’ big bed?
“I can’t sleep. Can I get in?”
Alternatively, might children begin dreaming even earlier, and only start talking about it as preschoolers?
To solve this mystery, Roffwarg and associates undertook a classic study in 1966 (the associates included Dement, whose popular new book The Promise of Sleep is getting rave reviews). The research team began by studying sleep waves in newborns. The investigators believed that infants do not have REM sleep because they do not dream, but the researchers intended to discover what newborn sleep waves looked like. The team would continue to measure sleep waves throughout infancy and toddlerhood to learn when and how dreaming begins.
The startling discovery was, not only do newborns dream — even on the first day of life — they actually dream more than the college students in the original studies (Science, 1966; 152:604).
This study has been repeated several times, confirming and expanding our knowledge. We dream more in the first 2 weeks of life than at any other time. The visual part of the brain is more active during newborn REM sleep than during adult sleep. They seem to have more vivid visual dreams.
Infants 3 to 5 months old dream much more than infants 6 to 12 months old do. 18-month-olds dream almost twice as much as 3-year-olds do. By age 3, the amount of time spent dreaming per night is in the same range as that of young adults. As the wheel of time turns throughout life, each year we dream a little less (Science, 1966; 152:604).
If children dream from the moment that they are born, might they dream before that time? We now know that they begin to sleep at as early as 4 weeks of gestation (Electroencephalography and Clinical Neurophysiology, 1975; 38:175). REM sleep waves have been found at as early as 28 weeks of gestation, and REM sleep waves accompanied by the eye movements of dreams by 30 weeks of gestation (Principles and Practice of Sleep Medicine in the Child, WB Saunders, 1995). It seems dreaming begins 2 or 3 months before babies are even born!
Dreams appear to be a kind of parallel processing by which we integrate our experience, making new connections in our brains. In the uterus, babies probably dream about the muted light they see and the sounds they hear (heartbeats, voices, and music). After birth, perhaps they dream about the explosion of new sights, sounds, tastes, smells, and textures as they delight in getting to know their parents.
We may dream more during the day than we do at night! As mentioned earlier, when we sleep, we dream only about 20%of the time. During non-REM sleep, the brain rests. Growing evidence suggests that we have real dreams all day long, but these are not noticed because of the “loudness” of our senses and our conscious thinking (Principles and Practice of Sleep Medicine, WB Saunders, 1994). In a similar way, we have an unobstructed view of stars in the sky all day long, but we can’t see them because they are overwhelmed by the light of the sun.
At night, the stars and the dreams come out.
Nightmares are unpleasant dreams that awaken a dreamer from sleep.
Traumatic events are known to cause a predictable pattern of nightmares: first dreams that relive the event, then dreams that relive the primary emotion of the event using different scenarios (different pictures), then dreams that incorporate aspects of the event into other parts of life. Nightmares are an important means of addressing difficult events and emotions to weave them into the fabric of our minds in a constructive way. Because the forces that produce nightmares are simpler than the complex drives that may initiate our other dreams, nightmares might be a good entrance into understanding the significance of dreams in general (Psychiatry, 1998; 61:223-238).
Nightmares are thought to be most common between the ages of 3 to 5 years –the peak age for fears — they are said to begin around that time, or shortly before. Though I don’t know of any others who concur, the available evidence leads me to a vastly different conclusion: that just like other dreams, nightmares are most common long before the preschool period.
Stressful events, such as injections, circumcision (which should never be done without anesthesia), being left alone or dropped, or even feeling hungry, need to be learned about and integrated. It seems to me that anything worth crying about is worth dreaming about.
We know from older children that nightmares commonly follow surgery (Anesthesia and Analgesia, 1999; 88:1042-1047), tooth extraction (British Dental Journal, 1999 13; 186:245-247), and motor vehicle accidents (European Child and Adolescent Psychiatry, 1998; 7:61-68). Why wouldn’t they follow childbirth?
We don’t want to believe that our little ones experience anything unpleasant. So strong is this desire that it led to the long-held (now finally and forcefully disproved) belief that newborns don’t feel pain when circumcised. How absurd!
Knowing how much young babies dream and cry (and wake up crying), it seems equally absurd to me to believe that all of their dreams are happy ones. Birth is a wonderful and terrible experience. There is much to be happy about and much to learn about in the weeks that follow. Babies’ dreams must incorporate and address those things that bring them pleasure and those that make them cry. In all likelihood, the peak age of crying, the first 6 weeks, is also the peak age of nightmares.
These nightmares are not unsuccessful dreams. Far from it! They help babies learn and grow; nightmares may even be an important reason that crying diminishes after 6 weeks.
Confusional arousals (popularly called night terrors) are an entirely different phenomenon, which I have described elsewhere. These happen when children get stuck between two stages of non-REM sleep. They might talk, scream, or open their eyes, but they aren’t awake and they aren’t dreaming.
Recently, my youngest son was having a confusional arousal, and his mother observed that these events are most common at the same ages that children are becoming aware of the bladder feeling full during sleep. Perhaps these kids just need to go to the bathroom. We stood him in front of the toilet, and he urinated-still not awake. The episode faded abruptly, and he returned to sleep. The calm was dramatic.
Was this a coincidence? Or might this be a revolutionary new help for parents whose kids have these frightening episodes? If readers try this and let me know what happens, we will find out. If you give it a try, let me know the results, either way. I’ll correlate the different experiences and broadcast the results. Together we can learn more about the wonder and mystery of sleep in children.
Aren’t they angelic when they are asleep?