Researchers at the University of Maryland School of Medicine note, “Elementary school-age children who get less than nine hours of sleep per night have significant differences in certain brain regions responsible for memory, intelligence, and well-being compared to those who get the recommended nine to 12 hours of sleep per night.” There were over 8,300 children who participated in their study. The researchers used MRIs, medical records, and surveys over a two-year period. They were particularly concerned to see that children who slept, on average, less than nine hours a night not only had less gray matter than their peers who slept nine or more hours but that the volume of gray matter remained low at the two years mark. Essentially, gray matter should increase during the elementary years until it peaks around 13 years of age.
While I am not an expert in neuroscience, I am going to take a stab at explaining, in a simplified way, what gray matter is and why it is so important. To start, gray matter is the outer layer of the brain and contains neuronal cell bodies (the spherical part of the neuron that contains the nucleus) and unmyelinated axons (tubes that carry electrical impulses from one neuron to another). Gray matter functions to process information in the brain. It plays a significant role in attention, the ability to retain memories, and the regulation of emotions. Those processes are extremely important during early childhood and elementary years when students are developing a foundation of skills and habits to be successful students.
In my readings, I learned that the American Academy of Pediatrics recommends “making sufficient sleep a family priority, sticking with a regular sleep routine, encouraging physical activity during the day, limiting screen time, and eliminating screens completely at least an hour before bed.” These guidelines were developed by the Academy in response to several recent sleep studies that have uncovered new understandings of the impact of sleep on neurodevelopment in children.
Whether it affirms your family’s current bedtime routine, prompts a conversation and development of a new plan for your family, or serves as a talking point with your children, an awareness of the importance and value of sufficient sleep, backed by science, is a good reminder.