Children who have experienced more intense and lasting stressful events score lower on tests of memory, suggesting stress may affect or delay brain development in young kids, new research has found.
The study, by researchers at the University of Wisconsin–Madison, suggests stress can alter the growth of a specific region of the brain and abilities associated with it, such as working memory, which may have a negative impact on learning.
"There has been a lot of work in animals linking both acute and chronic stress to changes in a part of the brain called the prefrontal cortex, which is involved in complex cognitive abilities like holding on to important information for quick recall and use," noted lead researcher Jamie Hanson, a UW–Madison psychology specialist. "We have now found similar associations in humans, and found that more exposure to stress is related to more issues with certain kinds of cognitive processes."
Researchers, writing in the Journal of Neuroscience, based their conclusions on studies they conducted on a group of children, aged 9 to 14. The UW team chronicled the children’s stressful events (from slight to severe), conducted brain scans and tested them on a range of memory-related skills.
They found children who had experienced more stressful events scored lower on tests of working memory and had more trouble performing tasks such as finding a token in a series of boxes. Brain scans also revealed that a key portion of the prefrontal cortex -- believed to play key roles in memory -- takes up less space in children with greater exposure to very stressful situations.
"These are subtle differences, but differences related to important cognitive abilities," Hanson said.
"There are groups around the country doing working memory interventions to try to train or retrain people on this particular cognitive ability and improve performance. Understanding if and how stress affects these processes could help us know whether there may be similar interventions that could aid children living in stressful conditions, and how this may affect the brain."
The study was funded by the National Institutes of Health.