Good sleep: a Cornerstone of brain development
It’s not just about recharging drained batteries. Sleep plays a vital role in learning. When their little eyes close, complex neurophysiological mechanisms kick in. What is the real impact of sleep on children’s cognitive development? How can we promote quality nights of sleep (and naps)? Here are a few tips gathered from experts.
The day is over. It’s been filled with discoveries, fun, grumbling, teasing, shared moments, and moments of deep focus. Soon, they’ll drift off into the arms of Morpheus. Calm settles in; everything seems to come to a halt. And yet: this apparent tranquility masks a veritable flurry of neurological activity. So many essential skills are consolidated as their heads rest on their pillows. A brief overview is in order.
Well-documented benefits, from birth through adolescence
The rapid advancement of neuroscience has made it possible to precisely analyze the mechanisms at work in the brain during sleep, and the scientific literature is unanimous in its conclusions. Sleep offers numerous benefits, which change with age.
1. From birth to age 2: rapid brain development
In infants, the brain grows extremely rapidly, and sleep phases take up a large part of the day. During these phases, increasingly complex neural networks develop.
A review of the existing literature highlights several benefits that occur during these periods: the consolidation of learning (everything seen and learned in the preceding hours), language development, and the strengthening of early memory and certain executive functions1. Longer, less fragmented sleep is often associated with better cognitive development, as well as psychomotor development.
2. Early childhood (ages 2–6): vocabulary, problems, emotions
Between the ages of two and six, young children seem to have boundless energy - sometimes much to our dismay. This overflowing energy shouldn’t make us forget the importance of a good night’s sleep and, for many of them, daytime naps.
Several studies show that young children who get enough sleep have better memory, a richer vocabulary, better problem-solving skills, and better inhibition2. This last quality refers to a mental process that filters out irrelevant information so that children can focus on specific tasks or important goals. It thus enables selective attention and the regulation of emotions and impulses.
Naps remain necessary to break up long periods of wakefulness. Studies indicate that they play a very important role in early childhood in consolidating what children learn during the day, complementing nighttime sleep.
However, all of the benefits mentioned must be viewed within a broader context. Sleep alone cannot guarantee all of these positive effects on brain development. It must be considered a contributing factor, alongside other essential elements such as the family environment and cognitive stimulation.
>> Stimulating versus overstimulating - what's the difference? Read the answer here.
3. During childhood (ages 6–12): attention and academic achievement
The scientific evidence regarding the importance of sleep is strongest for school-age children. It particularly highlights the harmful effects of insufficient and/or poor-quality sleep, such as a decline in sustained attention, reduced working memory, less effective executive functions, and lower academic performance2.
Conversely, regular sleep promotes memory consolidation and facilitates the transfer of knowledge from short-term to long-term memory.
4. Adolescence (ages 12–18): a particularly sensitive period
It’s no secret that our teens go through several years of major upheaval. Some will start acting unusually nonchalant, some will turn into sleepyheads who are impossible to get out of bed, and some will become impulsive and unpredictable… You might find yourself wondering - and quite rightly so. “But just a month ago, he was so full of energy.” “But not long ago, she used to wake up every morning at the crack of dawn.” “But just yesterday, they were listening to us so well.” “But that was before.” All these changes are perfectly normal, no matter how sudden and intense they may be.
The upheavals of adolescence cannot be controlled. Why? Teenagers undergo profound changes in their brains, particularly a critical maturation of the prefrontal cortex (the area of the brain that manages high-level executive functions, such as decision-making, planning, and emotional control). In fact, to give them a little credit, did you know that the brain isn’t considered fully mature until age 25 - or even 30 to 32, depending on the source3?
Among adolescents, therefore, chronic sleep deprivation is associated with: reduced cognitive performance, poorer attention, impaired executive function, less effective memory, and increased emotional and behavioral difficulties2.
These effects are amplified by the natural shift in their biological clock, which causes them to fall asleep later, even though school schedules require them to wake up very early. In fact, there is a recurring debate about changing these school schedules to have classes start later.
Respecting their sleep patterns is essential, including for their academic performance. A recent study of more than 3,000 adolescents showed that those who slept slightly longer - by going to bed earlier to compensate for waking up too early - scored higher on reading, vocabulary, and problem-solving tests and also had slightly larger brain volumes4.
What are the basics of good sleep?
The quality of sleep is assessed based on several criteria, as listed by Santé Publique France (the national public health agency under the supervision of the Ministry of Health)5:
- Duration: getting enough sleep for one’s age group (see box below) ;
- Quality: feeling rested upon waking ;
- Consistency: few prolonged nighttime awakenings (very brief awakenings between sleep cycles are normal);
- Regularity: maintaining relatively consistent bedtimes and wake-up times, including on weekends and during vacations ;
- Daytime impact: sustained levels of alertness, concentration, and memory, as well as a stable mood, throughout the day. This last point applies especially to children over age 6, adolescents, and adults
Recommended amount of sleep over a 24-hour period (including naps)
Note: These figures are provided as a general guide. Individual needs may vary slightly.
| infants (up to 1 year old) | 12 to 16 hours |
| 1 to 2 years | 11 to 14 hours |
| 3 to 5 years | 10 to 13 hours |
| 6 to 12 years | 9 to 12 hours |
| 13 to 17 years | 8 to 10 hours |
| 18 to 64 years | at least 7 hours |
| 65 and older | at least 8 hours |
To promote good sleep, experts in this field regularly highlight a few key recommendations that apply from childhood through adulthood.
- Go to bed at the first signs of tiredness. Keep an eye on the children at the end of the day: as soon as they start yawning, their eyelids feel heavy, or they become a little “hyper,” it’s time to suggest they slow down and settle into a new routine that will help them fall asleep.
- Limit screen time before bed, at least 1 to 2 hours before your desired bedtime. The harmful effects of blue light on the production of melatonin, the sleep hormone, are well established. Also keep in mind that social media and its fascinating ability to capture your attention for hours on end create a state of alertness that disrupts deep sleep.
- Create an environment conducive to sleep, with a quiet, dark bedroom (perhaps with a small nightlight), and a room temperature ideally between 18 and 20 degrees.
>> Need advice on how to manage their screen time? Check out our in-depth article.
Finally, opt for quiet activities in the evening. A little pillow fight now and then is fine. But children will find it easier to fall asleep after reading for a while or listening to some soft music.
To unwind after a long day, turning on the TV might seem like a great option. However, not all shows are suitable for bedtime. Not to mention the risks of excessive screen time for young children, even a short episode of CoComelon or Paw Patrol at the very end of the day can keep the Sandman from coming. The pace of some shows stimulates the brain a little too much at a time when it should, on the contrary, be preparing to wind down.
Our children’s sacred sleep is a resource worth protecting. In fact, it remains valuable at every age, including for us adults. It is during sleep that brain plasticity is maintained - the “brain’s ability to modify, reorganize, and remodel its neural connections and networks in response to experiences, learning, or following an injury” (according to the Brain Institute). It is also during sleep that much of the brain’s metabolic waste is cleared away, which helps reduce age-related cognitive decline. Something to think about before setting a good example for your children and heading off to bed.
Sources :
- Tham EK, Schneider N, Broekman BF. Infant sleep and its relation with cognition and growth: a narrative review. Nat Sci Sleep. 2017 May 15;9:135-149. doi: 10.2147/NSS.S125992. PMID: 28553151; PMCID: PMC5440010.
- Mason GM, Lokhandwala S, Riggins T, Spencer RMC. Sleep and human cognitive development. Sleep Med Rev. 2021 Jun;57:101472. doi: 10.1016/j.smrv.2021.101472. Epub 2021 Mar 13. PMID: 33827030; PMCID: PMC8164994.
- Mousley, A., Bethlehem, R.A.I., Yeh, FC. et al. Topological turning points across the human lifespan. Nat Commun 16, 10055 (2025). https://doi.org/10.1038/s41467-025-65974-8
- Ma Q, Sahakian BJ, Zhang B, Li Z, Yu JT, Li F, Feng J, Cheng W. Neural correlates of device-based sleep characteristics in adolescents. Cell Rep. 2025 May 27;44(5):115565. doi: 10.1016/j.celrep.2025.115565. Epub 2025 Apr 16. PMID: 40244849.
- Santé Publique France : Dossier Sommeil ; mis à jour le 3 avril 2026
