Babies do not have the same sleeping patterns as adults and are born with a pretty free-flowing body clock and sleep many more hours than we do. Sleep researchers have also discovered that babies in the womb and newborn babies spend at least 50% of their sleep in dream sleep, also called rapid eye movement (REM) sleep.
Our brains require different types of sleep during the night and scientists monitor what happens as the brain sleeps.
Sleep researchers have identified different stages of sleep that we and our babies need to restore, grow, rest and learn.
When we go to sleep we spend roughly the first two hours in deep sleep.
Deep sleep is restorative sleep and is a ‘slow wave’ sleep and our brains are resting at this time, i.e. not actively processing.
However, some people are still able to get up and walk around during deep sleep – this is sleepwalking, and this is when children may be having things like night terrors or sleep walking, can happen at that point of the night.
Night terrors are not bad dreams as dreaming only happens during REM sleep. Night terrors are due to physiological changes during sleep such as slowing heart rate, reducing blood pressure and decreasing body temperature.
We then spend the majority of our night, in a mid-level sleep, but then every now and again the brain moves into REM sleep cycle.
REM stands for rapid eye movement sleep because our eyes flit constantly during this sleep phase. It is also referred to as dream sleep.
REM mainly occurs at the last stage of sleep in the early morning, we are unlikely to have REM in the first third of our sleeping night.
During REM, we consolidate what we have experienced and learned in the day. We process experiences and we store them in our memory.
REM is vitally important to babies and children as they are learning so many new things each day. Indeed, newborns spend half of the time in REM and this helps your baby’s memory, learning, and understanding.
REM sleep is also the time when your child might have a nightmare. Nightmares are more likely to happen during morning sleep and night terrors in deep sleep so look to what time your child wakes up frightened to work out what is causing the fear.
During REM sleep, we are in a semi-paralysed state so that we don’t act out our dreams (that may be why people say dogs are chasing rabbits when their legs twitch and they do muted barks in their sleep!).
Another reason that it’s very important that we are in the semi-paralysed state during REM is that during this time your baby’s body is resting and restoring. Your baby will grow during REM and tissues in the body will be repaired too.
Deep sleep is similar to when a computer is shut down. To reboot or wake up at this stage takes time and you will feel very confused, tired and not alert. In contrast, REM is similar to a computer that has gone over to screensaver or ‘sleep’ mode. Just by touching the keyboard the computer is fully functioning. People are much easier to wake up from REM – which is why it’s often easier to wake someone up in the early hours of the morning compared to the dead of night when they will be in deep sleep phases.
The change from being awake to being asleep as fairly abrupt. Although it feels like you drift into sleep, the change is actually sudden. This is more obvious in babies who are endlessly appearing on “YouTube”, suddenly falling asleep on everything from rocking horses to high chairs.
For the first 2 hours after babies go to sleep, they are in deep sleep. You’ll notice through this time they don’t seem to stir. You can hoover around their room and they will stay asleep. It’s good to know this – so you have a window to get things done – or watch some TV!