US researchers examining the EEG (electroencephalograph) brain patterns of 9 and 10-year old children found that compared to children from wealthier socioeconomic backgrounds, those from poorer socioeconomic backgrounds had a noticeably lower level of activity in the prefrontal cortext, the part of the brain that is important for creativity and problem solving. This is reported to be the first study to show that the brains of low income kids behave differently to those of high income kids.
The study, which is to be published in the Journal of Cognitive Neuroscience, is the work of researchers from the Helen Wills Neuroscience Institute and the School of Public Health at the University of California, Berkeley.
An EEG machine is essentially a skull cap fitted with electrodes that detect electrical activity in the brain. The activity shows up as different patterns that can be used to assess conditions like sleep disorders, brain tumors and epilepsy.
Co-author Rober Knight, who is director of the Helen Wills Neuroscience Institute and a UC Berkeley professor of psychology, said in a press statement that:
“Kids from lower socioeconomic levels show brain physiology patterns similar to someone who actually had damage in the frontal lobe as an adult.”
“We found that kids are more likely to have a low response if they have low socioeconomic status, though not everyone who is poor has low frontal lobe response,” he added.
Other researchers have suggested a possible link between frontal lobe function of children from different socioeconomic backgrounds and behaviour, but, as cognitive psychologist and first author Mark Kishiyama explained:
“Those studies were only indirect measures of brain function and could not disentangle the effects of intelligence, language proficiency and other factors that tend to be associated with low socioeconomic status.”
“Our study is the first with direct measure of brain activity where there is no issue of task complexity,” said Kishiyama.
W. Thomas Boyce another co-author of the paper who is UC Berkeley professor emeritus of public health and currently holds the British Columbia Leadership Chair of Child Development at the University of British Columbia (UBC) said he was not surprised by the findings:
“We know kids growing up in resource-poor environments have more trouble with the kinds of behavioral control that the prefrontal cortex is involved in regulating.”
“But the fact that we see functional differences in prefrontal cortex response in lower socioeconomic status kids is definitive,” added Boyce, who is a pediatrician and developmental psychobiologist, and head of a joint UC Berkeley/UBC research program called WINKS – Wellness in Kids. WINKS researchers are looking at how the disadvantages of being raised in low socioeconomic circumstances affect children’s early neural development.
Knight called the findings a “wake up call”, explaining that:
“It’s not just that these kids are poor and more likely to have health problems, but they might actually not be getting full brain development from the stressful and relatively impoverished environment associated with low socioeconomic status: fewer books, less reading, fewer games, fewer visits to museums.”
Kishiyama, Knight and Boyce suspect that it is possible to reduce the brain differences between wealthier and poorer children with training. They are currently working with neuroscientists at UC Berkeley who are investigating the possibility of developing the prefrontal cortex and reasoning skills of schoolchildren using games.
Knight said it was not a “life sentence”, and that with “proper intervention and training, you could get improvement in both behavioral and physiological indices”.
For the study, Kishiyama, Knight, Boyce and colleagues picked 26 children aged 9 and 10 from the WINKS study. Half the children came from low income families and half from high income families. They measured the EEG brain activity of each child while he or she watched shapes on a screen and had to press a button when they saw one out of alignment.
“An EEG allows us to measure very fast brain responses with millisecond accuracy,” said Kishiyama.
The scientists noticed a significant difference in how the prefrontal cortex responded in the two groups, not just when they saw an image out of alignment, but also while they watched the upright shapes and waited for a skewed one to show.
The children in the lower socioeconomic group showed a lower response when an unexpected shape appeared. Kishiyama said the response was similar to that of people who have had a stroke or part of their frontal lobe destroyed.
The prefrontal cortex helps you process visual stimuli, especially when unexpected ones occur. But with both expected and unexpected shapes, the kids from the lower socioeconomic backgrounds were not detecting and processing the visual stimuli as well, said Kishiyama.
“They were not getting that extra boost from the prefrontal cortex,” he said. Even though these kids don’t have any brain damage, they haven’t been exposed to alcohol or drugs in the womb, their prefrontal cortex did not function as well as it should. “This difference may manifest itself in problem solving and school performance,” said Kishiyama.
The researchers suggested that it was stress and lack of cognitive stimulation that led to the lower function of the prefrontal cortex in the poorer kids, because experiments show that animals raised in stressful and deprived conditions also show reduced prefrontal function.
Sources: UC Berkeley.
Written by: Catharine Paddock, PhD