Do babies dream? It’s an age-old question with a complicated answer. Even the youngest babies can be very active in their sleep, making some pretty funny noises or faces. When you see a slumbering baby twitch, smile or smirk, you might imagine they’re drifting through a dreamworld, perhaps floating through a rainbow sky or playing with the family dog.
In truth, there’s a lot that even scientists still don’t know about the infant brain. Here, human development and neuroscience experts break down what they do know about whether babies dream and what’s going on in babies’ brains while they’re asleep.
Do babies dream when they’re asleep?
The short answer is, we can’t say one way or the other.
“Right now, with our technology, it does not appear to be possible to know the answer to the question of whether or not babies dream,” says Dr. Melissa Burnham, a professor and chair of the Department of Human Development, Family Science and Counseling at the University of Nevada, Reno.
That’s because the only way we know that anyone dreams is that they can talk about their experiences. So, until a child is old enough to wake up and tell you, “I saw the craziest thing in my dream,” we can only wonder.
What we do know is that babies’ slumbering brains are very busy. While they’re sleeping, research shows they consolidate memories of things they experienced while awake and may even be processing stimuli in their environment. That’s why sleep is so crucial for infant development.
What’s more, an infant’s brain works differently than an adult’s or older child’s, even during the daytime. While they can store memories, they don’t develop “episodic” memories — or, recollections of specific events — until age 3 or 4 years. If babies do perceive images or sounds in their sleep, “it’s probably not in the same form as what we think of a dream,” says Burnham.
How are babies’ sleep cycles different from adults?
As new parents know, newborns might nod off in broad daylight and be ready to party at 2am. That’s because they aren’t born with circadian rhythm — the natural internal cycles that signal to our body when it’s time to sleep. This function has to be developed over the first few months of life.
When adults fall asleep, we go through two sleep phases: non-rapid eye movement (NREM) sleep, and rapid eye movement (REM) sleep, which is associated with vivid dreaming. A full sleep cycle involves going through all of these states, and a typical night might consist of four to six sleep cycles, each lasting an average of 90 minutes.
Newborns, on the other hand, snooze 16 to 18 hours per 24-hour period, broken into short chunks of time. According to the existing research, a given sleep session for a newborn consists of only one or two sleep cycles. During these cycles, they may go through several phases:
- Active sleep.
- Quiet sleep.
- Indeterminate sleep.
How can you tell which sleep phase a baby is in? If you’re watching your baby sleep and notice their breathing becomes irregular, their eyes are moving and their hands are jerking, “that’s active sleep,” says Burnham.
When they become quiet and still, they’ve probably moved into the “quiet sleep” phase. If a baby isn’t showing the specific behaviors characteristic of either active or quiet sleep, they’re in “indeterminate sleep.”
When do babies start dreaming?
Experts don’t know at exactly what age people begin to form dreams, but you might hear children start to describe them beginning between 2 and 3 years old, says Burnham. Sometimes, the first dreams kids and parents talk about are bad dreams.
“Young children around age three will often start having scary dreams,” Burnham explains. “It’s usually about something very intangible or something they saw during the daytime that’s revisiting them…something that their brain is working out.”
What do babies’ sleep sounds and movements mean if they’re not dreaming?
Infants are highly active in their sleep — they typically move more often than adults or older children. Why do they do this, if not because of dreams? That’s a question that some researchers find even more compelling than whether they dream.
“Infants have more REM (or active) sleep than adults, and one of the defining features of REM sleep is the twitches of the limbs, eyes, face, etc.,” says Mark Blumberg, a neuroscientist and chair of the Department of Psychological and Brain Sciences at the University of Iowa. He and other researchers theorize that twitching in sleep may help infants’ brains develop.
“Twitches are produced in the brainstem, and the sensory feedback arising from the movements cascades through the sensorimotor system, ultimately activating neurons in the cortex,” Blumberg explains. Rather than twitches being the result of dreams, he adds, “I believe that dreams are more often the consequences of these movements than their cause.”
This is because the sensations arising from twitches can specifically activate parts of the brain that external stimulation cannot. Blumberg adds that these self-generated movements, or twitches, help build precise and functionally complete brain circuits.
The bottom line
Whether or not babies dream, their brains are doing lots of hard work while they snooze. Kids of all ages need a lot more sleep than the typical adult. Most infants don’t sleep through the night until they’re at least 4-6 months old, and many continue to wake at night well beyond that age. So, while we may be left to wonder what’s actually going on in their minds, there’s no question that whatever it is, it’s helping them grow and thrive.
