Sleep deprivation disproportionally affects developing portions of kids’ brains
There are many concerns with sleep deprivation in children, starting with the sanity of anyone around them. Kids don’t always react to needing sleep with the same lethargy that adults do, sometimes getting hyperactive and inattentive instead. Whatever their energy levels, kids also suffer some cognitive impairment, which in a six-year-old can mean unusual difficulty in identifying and parsing spoken speech. This goes beyond just “being an inattentive listener” though, as the brain literally cannot function well without enough sleep. In adults, this kind of impairment is generally temporary, but there’s a chance that children might not bounce back from chronic sleep deprivation, because their brains are still growing.
A recent study looked at the brain activity of rested versus sleep deprived children. In this case, the sleep deprived kids weren’t regularly missing sleep, but were instead kept up half a night by their parents with reading and playtime. The children wore caps with a matrix of electrodes on their heads, allowing researchers to monitor their general brain activity throughout the experiment. As in adults from other studies, the sleepy children’s brains showed a lot of “slow wave” activity patterns, which is normally seen when we’re in deep sleep. In contrast to rapid eye movement (REM) sleep when we dream and apparently encode memories, slow wave sleep has been linked to restorative processes in various body systems, including the brain itself. The main difference seen in the sleepy children was where this activity was turning up.
Impairment in immature brain regions
Sleep deprived adults suffer most in our prefrontal cortex, where we do a lot of calculations and cognition, explaining why things like taking a test when you’re tired is such a bad idea. The sleepy children in this study had more unusual activity in the back of their brain around the parietal and occipital lobes. These parts of the brain are associated with sensory information, navigation and visual processing. However, researchers weren’t looking for child-specific symptoms of sleep deprivation associated with these brain regions. The bigger question was why children’s brains were different from adults’ when they were exhausted.
The most likely reason that sleep deprivation is affecting different parts of kids’ brains is brain growth itself. As a brain matures, it coats some nerve bundles in a protein called myelin. In limiting the branching connections to myelinated neurons, the brain also reinforces and insulates these pathways, making them faster and more reliable. The measurements of the sleepy children’s brains showed that areas with a more mature amount of myelin were more likely to look like an adult’s sleep-deprived brain. Areas that hadn’t had time to develop as much myelin, such as the aforementioned parietal and occipital lobes, were more unusually affected. At this point, it’s not known if sleep deprivation can cause lasting changes to brain areas too young to be myelinated, but odds are it’s not worth finding out.
Source: How kids' brains respond to a late night up by Frontiers, Science Daily
