Children who experience chronic stress are more likely to have a smaller brain region linked to memory than their less-strained counterparts,a new study has found.
The brain differences also bore out in cognitive ability,with the children having highly stressful lives performing poorer than other kids on spatial memory tests,according to researchers at the University of Wisconsin-Madison in the US.
The highly stressed children also had more trouble with tests of short-term memory,including tasks such as finding a token in a series of boxes,the researchers said.
All families experience some stress,so it is important to note that effects were found for high levels of stress,” study researcher Jamie Hanson told LiveScience.
Some extreme examples would include family members falling victim to violent crimes or the chronic illness of a child or other family member,Hanson added.
The study,published in the Journal of Neuroscience,adds to a growing body of evidence on the impacts of stress. While a recent study found that kids exposed to multiple instances of violence age faster on a cellular level,another study had suggested childhood stress could actually take years off an individual’s life.
In the study,the researchers interviewed 61 kids aged between nine and to 14,asking about stressful events of their lives. They also used magnetic resonance imaging (MRI) to scan each participant’s brain and found the anterior cingulate,which resides in the prefrontal cortex,took up less space in the highly stressed children.
The anterior cingulated cortex is thought to play a role in a range of emotional and cognitive tasks,including spatial working memory,where spatial information can be processed and accessed quickly. These are subtle differences,but they are related to important cognitive abilities, Hanson said.
The researchers also looked at differences in the amounts of gray matter and white matter in the brain,finding both types of tissue showed smaller volumes in the overly stressed group compared with the not-so-stressed.
Though they aren’t sure of the mechanism behind the links between stress and brain changes,they believe that exposure to very high levels of stress could change important chemicals in the brain and body.
Noting two chemicals of particular interest,cortisol and dopamine,Hanson said,the hormone cortisol tends to increase with stress and can affect brain cells. There’s also a chance the seemingly stunted brain development is just temporary.
We’re not trying to argue that stress permanently scars your brain. We don’t know if and how it is that stress affects the brain, Hanson said.
We only have a snapshot,one MRI scan of each subject,and at this point,we don’t understand whether this is just a delay in development or a lasting difference.
It could be that,because the brains is very plastic,very able to change,that children who have experienced a great deal of stress catch up in these areas.