It may seem like an odd thing for something new and so small but yes, they really are. In fact, up until 4 months of age, babies will spend the majority of their sleep time in REM (rapid eye movement, or “dream” sleep). It is widely assumed that NREM (Non REM, or deep sleep) is the most beneficial phase of sleep. So why are newborns stuck in REM sleep? And is it harmful for them?
While NREM sleep has many important functions for human survival, REM sleep is actually ESSENTIAL for a developing brain. This is because REM sleep acts as an enabler for the brain to develop its vast network of neural pathways, which is is unable to do during wakefulness. Matthew Walker likens this to an internet service provider populating new towns and cities with fibre optic cables. REM sleep not only facilitates the groundwork for these cables, but the high bolts of electricity produced during REM sleep activates their high speed functioning.
Given the colossal task of establishing neuro-architecture that will engender thoughts, memories, feelings, decisions and actions (to name just a few functions), it is no wonder that REM sleep dominates the vast majority of our newborn babies lives.
But what do babies dream about?
It is unlikely that babies dream in the same way that most of us think of as “dreaming”. The hypnic jerks, startle responses, cries and leg kicks we see our babies do are actually due to the fact they haven’t yet fully developed the body paralysing mechanism of REM sleep that (most) adults have in place. In fact, the majority of baby kicks in utero are actually a result of them being in a state of REM sleep rather than being awake and deciding to kick out!
So do we know what babies dream about?
Not entirely, as it is impossible to question a newborn about their sleeping state upon waking. However, what we do know is that REM sleep plays an absolutely vital role in our babies development. Which, in my opinion, is another very good reason for NOT waking a sleeping baby.
Paediatric Sleep Coach
MSc & BSc hons
Walker, M (2018). Why We Sleep. Penguin Books. London