Posted by on Oct 20, 2014 in Sleep Science | 0 comments

I’ve always been fascinated by the physiology of sleep. It’s part of what led me to become a sleep coach. After having four children of my own, I began to read more about the science of sleep and what’s really going on when we sleep at night. I wanted more insight into why my children were still waking several times a night at six months of age and had some difficulty settling back into sleep. As it turns out, some of the explanation lay in better understanding the science of sleep.

Stay with me, as I introduce a few technical terms and briefly touch on sleep cycles, which is sometimes referred to as sleep architecture.   In the context of sleep coaching, it’s really helpful, and I think particularly fascinating, to understand sleep cycles and how they work.

There are two basic types of sleep all humans cycle in and out of throughout the night, REM (Rapid Eye Movement) and non-REM. REM sleep is the active and lighter stage of sleep of the two, when our eyes can be seen moving beneath our eyelids, some twitching might been observed, limbs are limp, and breathing is irregular. REM sleep is also when we are dreaming.

Non-REM sleep, on the other hand, is a deeper stage of sleep. Non-REM has stages of it’s own, light sleep, true sleep, and deep sleep. It is the deep sleep stage of non-REM sleep that our respiration slows, our muscles are tenser, and it is most difficult to be awoken. Throughout the night, as we sleep, we all pass through these stages of sleep. Babies and children are no exception, although their sleep cycles don’t mimic those of adults until the age of two.

It’s important to understand this in the context of sleep coaching. Up until the age of two, children spend more time in REM sleep than non-REM sleep and are more easily aroused as a result. We all cycle in and out of REM and non-REM sleep at night, children under the age of two, just do it more often. This change in our brain activity causes many babies, whose brains are still rapidly developing, to experience a partial arousal. Your baby may cry out, startle, or thrash their body when this happens. They may also cry out for you to help them get back to sleep.

This is where your help comes in. For children who have negative sleep associations or sleep crutches, such as being nursed or rocked to sleep at bedtime, they will require your assistance to get back to sleep in the middle of the night when they experience a partial arousal. This will cause them to become more awake, causing a complete arousal. It’s like they are saying “hey Mommy, you fed me before bedtime to help me get to sleep and now I’m awake again and I can’t get myself back to sleep unless you feed me again, even though I’m not really hungry”.

When your baby is mature enough to learn how to consistently self soothe, which for most babies is around eighteen weeks of age, you can teach your baby gently to gradually give up these associations, helping them to sleep through the night. At this age, babies have a remarkable ability to self soothe, if given the opportunity. Start by giving your baby the opportunity at bedtime, when they are typically most drowsy, to put themselves to sleep. Put them down drowsy but awake at bedtime. You can do this with older children too, who are used to Mommy or Daddy lying with them to fall asleep at night. Give them the opportunity to learn how to drift off on their own. It might take more time and persistence with an older child, but it can be done.

Do this consistently at bedtime and gradually your child will learn to drift off to sleep without your assistance. It may not always be perfect, but over time, when your child wakes in the middle of the night, as they cycle through the stages of sleep, they will be able to soothe themselves back to sleep and the arousal will stay partial.