Our cognitive fates are not sealed – that was a powerful message that came out yesterday from a session on developmental cognitive neuroscience at the CNS meeting in Boston. In four talks, speakers laid out new ways neuroscience findings can help children learn, even if they are experiencing challenges because of a developmental disorder or environmental factors.
“Children are born into a neurodevelopmental lottery,”said John Gabrieli of MIT, citing dyslexia, rising rates of autism and ADHD, as well as various mental diseases including depression and bipolar disorder. A growing body of work, however, is showing that neuroscience can “reveal secrets” about the brains of children that behavioral measures alone cannot – enabling researchers to better predict children’s future learning success.
Gabrieli then described two large-scale studies he and colleagues have undertaken to try to uncover these secrets and use them to help children in the real world. In one study, his team screened more than 1,400 kindergartners in 19 Boston-area schools for early reading indicators to see if they could construct a model to predict their later reading skills. Of those children, they brought 180 participants into the lab for behavioral testing combined with fMRI and EEG measurements and have been following them through 1st and 2nd grade. The researchers were specifically interested in “phenological awareness” – the ability to manipulate language sounds, such as asking the kids to say the word “bold” without using the sound “/b/.”
Using diffusion-weighted imaging, which is based on fMRI, they looked at the white matter in the brain regions associated with reading skills (the arcuate fasciculus, the inferior longitudinal fasciculus, and the superior longitudinal fasciculus). “In these pre-reading children, the volume and the micro-structures of the white matter pathway correlated quite strongly with their phenological awareness,” Gabrieli said.
In another study, Gabrieli and colleagues looked at whether schools can can influence crystallized skills – facts and figures like standard math and vocabulary – and fluid skills – things like working memory, abstract reasoning and processing speed. Looking at some 1,300 8th graders in 32 middle schools, they found that certain schools could boost testing performance on crystallized skills but not fluid skills.
In a follow-up new study, the researchers focused on charter schools, which accept children based on a lottery system. This way they could look at two random groups – those who got into the charter school or did not – to compare brain structures and standardized test scores. They found again that those who got into the charter schools had bigger gains in crystallized skills than those who did not.
In a small sample of children who came in for further testing, including a working-memory test, the researchers found a correlation between children with greater cortical thickness and higher standardized test scores. They also found a correlation between children’s socioeconomic status – indicated by those who receive free lunches – and cortical thickness.
So some schools, including charter schools, can really make an impact on crystallized skills and test scores – which have been linked to future success on SAT scores, AP scores, and eventually higher education and income.
“We know that many abilities and disabilities of all kinds, cognitive and emotional, are rooted in early child development, and we hope that the combination of careful behavioral, brain, and perhaps genetic measures will promote early interventions that promote long-term success and happiness in children,” Gabrieli told CNS.
The effects of poverty on children’s brains
Beyond the impact of child’ school or a particular developmental disorder, environmental factors have a big influence on children’s brains. Researchers are finding that day-to-day parenting decisions and exposure to adverse situations (discussed in detail by Margaret Sheridan of Boston’s Children Hospital) affect cognitive development.
Oftentimes, these environmental factors come down to socioeconomic status. Martha Farah of the University of Pennsylvania started by addressing the question of why neuroscientists should look at childhood poverty: “Understanding human behavior is hard – you need all the sources of understanding you can get,” she said.
Study after study has shown a consistent signal, Farah said: “The world is telling us that childhood socioeconomic status shapes brain structures and function in fairly consistent and fairly specific ways.” For example, across three studies with kindergartners, researchers found that low socioeconomic status impaired language, executive function, and learning and memory skills.
The possible reasons for this link are manifold, including everything from prenatal nutrition and toxins in the environment to stress and cognitive stimulation. In one project to look at the impacts of parenting and cognitive stimulation in the home, researchers tested kids in middle school (11-13 years old) after having interviewed their caregivers in their home environment at ages 4 and 8. These children were part of longitudinal study, having been recruited at birth and being followed for 20 years. In the interviews, research assistants asked the caregivers about the children’s typical days and parental interactions, as well as observed the parents’ behavior with their children and the environment itself.
They found that seemingly little things in parenting like making available a toy or real musical instrument, posting children’s artwork, and just talking to kids one-on-one did predict language skills in middle school. They also found that parental nurturing – holding a child, speaking gently, giving a child a pet name – positively influenced memory performance.
Why would parenting affect memory? “This is where going neuro earns its keep,” Farah said. Both stress and memory, she explained, depend on the hippocampus. Scientists know from studies with rats that maternal care helps protect pups from the effects of stress; more maternal care predicts better stress response and better memory. “The ability of a baby to control its own stress responses isn’t mature and depends, in humans, on cuddling, gentle talk, etc., to help damp down stress response and to spare the hippocampus from an onslaught of stress hormones.”
Throughout the talks, the researchers cited the scientific evidence for the many factors that impact children’s cognitive development while also showing the potential for change: projects that are literally altering the brain structures and functions in kids.
For example, Helen Neville of the University of Oregon discussed a partnership she and colleagues have created with Head Start, a program geared toward children aged 3 to 5 living at or below the poverty line. They have had over 500 participating families to date. This “hybrid intervention” aims to train children in attention and parents on both parenting and attention.
In weekly training for parents, researchers talked to parents about what their kids are doing in the next room to improve their attention – activities like walking down a ribbon to deliver a cup of water to a (pretend) frog. They also gave them tools for interacting with their children, for example advising parents to give their kids choices. Rather than asking them to go to bed, parents should instead ask them: “Do you want to go to bed now or in 5 minutes?” This gives kids more of a feeling of control in their lives and they are then more likely to cooperate. Neville recalled that parents would come back after that lesson and say: “I can control my children for the first time.” The researchers also worked with parents to help them manage family stress, teaching things like the importance of breathing.
They have found that the children whose families participated in this intervention program had improvements in a host of cognitive areas, including in language and nonverbal IQ, as well as stress management, compared to control groups. Neville’s team continues work on this project, which has now been adapted for Spanish-speaking families (“ Creando Conexiones”).
Neville pointed out that the cost of this intervention is relatively low, about $800. She and colleagues estimate a 9:1 return on investment – with benefits ranging from improved self-esteem to increased rates of high school and college graduation to better employment. (Visit changingbrains.org for more about the intervention work by Helen Neville.)
-Lisa M.P. Munoz