Last week I shared the foundation for early learning and kindergarten success: a set of tools called executive function (such as the ability to retain information, be flexible and control attention and impulses). These brain and thinking skills are key to school readiness, and predictors of many developmental outcomes such as school achievement. This week I want to share three research studies that focus on executive function. To help kids, parents and teachers, my team at ICD (Institute of Child Development) at U of MN CEHD is taking an in-depth look at the effects of sleep, stress and nutrition on executive function.
The Quality of Infant Sleep
Our research team examined sleep changes and their role on executive function development in pre-K kids in 2010. We conducted this study with Annie Bernier and other researchers from the University of Montreal. We found that infants at 12 months and 18 months who get most of their sleep during the night perform better in executive function when they reach 18 months and 26 months. This remained true even after we controlled for influences such as parents’ education, income and other socioeconomic factors.
While sleep quantity is important, it is the quality of sleep at night that is the reliable predictor of executive function. In general, children with a higher percentage of sleep during the night in the first two years of life were further along in the development of their executive functioning. We also noted several interesting findings that show sleep now affects performance later:
- How long infants 12 months old sleep at night is correlated to their executive function skills at 26 months.
- How long infants 18 months old sleep at night is correlated to their working memory at 18 months and impulse control at 26 months.
- At both 12 and 18 months, the infants with a higher amount of total sleep occurring at nighttime had better performance on executive function tasks, especially those involving strong impulse control.
- Nighttime sleep at 12 months predicted executive function skills into the preschool years, at age 4, over and above earlier predictions.
What Role does Nutrition Play?
To find out what role nutrition plays in the development of executive function in infants and toddlers, I’m working with colleagues Ellen Demerath in the U of MN School of Public Health and Michael Georgieff, director of the U of MN Center for Neurobehavioral Development. Together we’ll determine whether early feeding practices of infants might alter or influence brain development. We know that reward centers in the brain do play a role in executive function. Our goal is to examine issues of childhood obesity. For example, we recently found that preschoolers who crave sweet and sugary beverages have lower executive function performance. We also want to know if a feeding schedule for infants, or feeding “on demand” affect infant weight gain. Feeding on a schedule is associated with rapid weight gain early in life. But what are its long-term effects? That is what we’ll find out.
How do Poverty and Stress Affect Executive Function?
We’re teaming up with others from CEHD to study executive function in preschool-age children living in stressful environments. We are in the middle of a three-year study funded by the U.S. Department of Education Institute of Education Sciences. Working with Ann Masten, Distinguished McKnight University Professor, and Philip David Zelazo, the John and Nancy Lindahl Professor in ICD, we are studying 3- to 5-year-olds staying at People Serving People, one of the largest emergency shelters in Minnesota. The study will determine if guidance during an activity can help pre-K kids living in poverty enhance executive function. It’s an important group to study because Ann’s research as well as research from ICD Director Megan Gunnar has shown that children who endure poverty and stress are susceptible to poorly developed executive function. Philip’s research and my own has shown that teaching children the art of reflection helps boost their executive function skills, and we are especially motivated to work with this population.
In addition, we’ve started a three-week intervention program for parents staying at People Serving People. We know kids of all ages test the limits of their parents, and for parents dealing with such large amounts of stress, it’s even more difficult. We share how parents can recognize executive function in their kids and reward behaviors such as remembering to wait their turn. It’s about focusing on the positive. We are hoping to transform our findings into curriculum activities that teachers can use to promote thinking skills for a wide-range of students. We will share findings in a future blog.
The study of executive function and its effect on school readiness is very important, as these skills are the foundation for learning. It is our hope that education specialists will eventually be able to screen for measures of executive function in children, and then identify students who need help.
Check back to the Vision 2020 blog for updates on my research on how factors such as nutrition and sleep can affect executive function. Subscribe to our blog for the latest in education and human development research.