The Science Behind “Mom Brain”

By Gillian Mandville

November 19, 2019

Gillian is a Registered Nurse, Lactation Counselor, and Sleep Coach working with families in Victoria. Becoming the mama of her baby boy has ignited her passion to want to help new moms and families through their unique parenthood journey.

Whether or not you’ve had a baby or have been pregnant, no doubt you’ve heard women talking about “mom brain.” To make things clear, for this article, we are talking about the absolute amnesia many of us seem to experience once a baby comes into our lives. It seems that babies successfully ambush our brains and suddenly we are doing ridiculous things and forgetting major steps in our day to day lives that we’ve done hundreds of times before! We are forgetting full conversations we’ve had with friends. We’ve forgotten to pick up items that we knew we needed to get for days. We come home from the grocery store and of course, we didn’t even get what we went there for in the first place. We are even forgetting to add the flour to our cookie batter (true story).

What the heck is happening to us?! Am I losing my mind or is there (please) something more to this? Good news, mamas. You already know you are NOT alone, but did you know that the reason for these very annoying and very real post-baby memory lapses is based on the science of sleep? That’s right! It’s no secret that new moms (let’s say, moms in general) are big-time lacking in a good, solid night’s sleep. What many people may not know is that our memory consolidation and information processing takes place in Stage 2 of Non-REM Sleep!

Non-REM Sleep Stage 1

Let me, in a nutshell, run through the adult sleep stages with you. We, as adults, have REM sleep and Non-REM sleep. In non-REM sleep, there are 3 stages. We cycle through all the sleep stages (including REM sleep) 4-5 times throughout the night. One full cycle for adults lasts between 90-120 minutes. The first stage of non-REM sleep occurs when you are in bed, lights are out and you start feeling drowsy and your brainwaves slow. The period between awake and asleep. This stage is usually less than ten minutes. 

Non-REM Sleep Stage 2

Stage 2 of non-REM sleep is where the memory magic takes place! The outside world begins to fade completely in this stage, you may hear sounds but you will not be able to differentiate what they are. If you were to be looking at brainwaves in this stage of sleep, the distinguishing characteristics you will find here are sleep spindles and K-complexes.

Together they serve to protect sleep and suppress the response to outside stimuli as well as to aid in sleep-based memory consolidation and information processing. We spend the bulk of our sleep in this stage, 45-50%. Now, you probably see where I’m going with this! Lack of sleep means not enough stage 2 sleep where we consolidate memories and process information, therefore it seems we are forgetting everything! MOM BRAIN!!! 

Non-REM Sleep Stage 3

Stage 3 of non-REM sleep is the deepest sleep or slow-wave (delta wave) sleep. There are some spindles here but delta waves make up the majority of the brain activity. Our temperature lowers, as do our blood pressure, breathing, heart rate, and brain activity. It’s very difficult to wake a person up who is in this sleep stage. Fun fact!! This is where one would experience night terrors and sleepwalking. Children spend more time in this sleep stage than adults. Elderly people spend very little, if any, time asleep in this stage.

REM Sleep

Last but not least, we have the REM sleep stage. You probably already know that REM stands for Rapid Eye Movement. Our eyes, while closed, will move side to side rapidly and randomly. The time spent in REM gets longer as the night (and sleep cycles) goes on and this sleep stage will dominate the early morning hours. Interestingly, our brainwaves will look very similar to a waking state! However, to the contrary, our muscles become completely paralyzed and unresponsive. The theory is that this occurs to protect us from acting out our dreams! Some memory consolidation occurs here, but not as much as in non-REM sleep. It’s interesting to know that REM sleep stimulates the area in our brains used in learning.

Well, this turned out to be a mini-crash sleep-stage education session. I find the science of sleep fascinating!! Are you finding it tough to remember to put the clothes in the dryer or figure out why you randomly just walked into the kitchen…what was it that you were looking for? You can’t remember arranging that baby date today that you just received a text about? If you’re suffering from mom brain and need help getting your little one sleeping through the night, please reach out! You can find me here! I’d love to help get you and your babe back on the sleep train! 

Share this Article