By Emily C. Merz & Melissa Hansen - Colorado State University
As neuroscientists, we are passionate about questions concerning the reduction of
socioeconomic disparities that can influence children's development. Accordingly, our goal is to better understand how such disparities affect sleep quality and brain development in young children.
For our most recent work, we recruited 94 children aged 5 to 9 living in New York, from families of varying socioeconomic statuses. Among the participating households, around 30% had incomes below the amount considered the poverty threshold in the United States.
Illustration image Pixabay
Our results indicate that lack of sleep and late bedtimes are associated with
functional changes in the brain. These potentially harmful changes are localized in brain regions important for dealing with stress and controlling negative emotions.
Our research also reveals that children from families with limited economic resources are particularly at risk of being affected by these brain changes.
Sleep impacts the amygdala
To measure the effect of sleep deprivation and bedtimes on children's brains, we asked their parents to describe where their children slept, as well as the various family routines and their regularity. We also asked them to record their child's bedtimes and wake-up times.
We also gave the children MRI scans to determine the size of a particular brain region
called the amygdala and the strength of its connections with other brain areas (
not to be confused with the tonsils, two glandular masses located on either side of the throat involved in trapping bacteria or viruses entering through the nose and mouth, ed.).
It is important to understand that the amygdala plays a
crucial role in processing emotions and the amount of negative emotions a person feels. It is well known that
early exposure to adversity can affect the functioning of this brain structure.
We found that children from families with limited economic resources slept less at night and went to bed later than children from families with more economic resources. This shorter sleep and later bedtimes were associated with a
reduction in amygdala size and
weaker connections between the amygdala and other brain areas involved in emotion processing.
This link between socioeconomic disadvantage, sleep duration and timing, and amygdala size and connectivity was observed in children as young as 5 years old. Our results suggest that sleep duration and timing are important for the functioning of brain regions involved in processing emotions.
Why this result is important
During childhood, the
brain develops rapidly. Experiences during this period of life can have long-term effects on brain function, lasting a lifetime.
Notably, lack of sleep increases the risk of
developing mental health problems and
interferes with academic success. Moreover, reduced sleep duration can make it more difficult to manage stress and emotions.
Why do socioeconomically disadvantaged children sleep worse?
As we've seen, children from families or neighborhoods with limited socioeconomic resources may be at greater risk of stress-related mental health problems, partly due to negative environmental effects on sleep quality. But why?
The data we've collected suggests that parents struggling to make ends meet have more difficulty maintaining family routines, which can negatively impact the
regularity of bedtime routines, thus leading to less restorative sleep for their children.
However, it's likely that there are
multiple factors explaining the links between lower socioeconomic status and poor sleep quality. Financial difficulties can, for example, prevent the purchase of comfortable bedding, force children to sleep in overcrowded, overly warm, or overly bright rooms, or require them to live in noisy neighborhoods, etc.
Our results argue for the implementation of policies that ensure all families have sufficient economic resources to meet their children's needs. Other research has shown that providing
income supplements to families in need can improve not only children's brain functions but also their
mental health and academic performance.
Finally, it's important to note that until now, most research on sleep has focused on adolescents, who are
particularly at risk of poor sleep patterns. However, our work suggests that the effects of our environment on sleep habits begin much earlier, in childhood. Therefore, interventions to improve sleep quality should be implemented as early as possible to achieve optimal outcomes.