When we take our young children to the doctor for a well-child checkup, an important component of the visit is to plot and then track the child’s development on a normalized height/weight chart. This comparison allows us to know if our child is developing appropriately.
University of Michigan Medical School researchers propose a similar method to determine if a child’s brain is on track for healthy attention abilities. They believe it may be possible to create a growth chart of brain networks that could identify early signs of attention difficulties and, potentially, attention-deficit hyperactivity disorder.
To test their theory, researchers created an experimental growth chart by mapping the development of brain networks in more than 500 children and teens. They found networks are underdeveloped in those who have attention difficulties.
Although the concept is in the early stages, future development of the technique could mean better chances for children to get a firm diagnosis of ADHD sooner. It could also help track whether their ADHD treatment is improving their attention functioning, which can help them in school and life.
The research, published in JAMA Psychiatry, shows the potential for brain imaging “biomarkers” for attention problems. But the idea could extend to other psychological conditions.
Traditional growth charts show a child’s height and weight as points on curves that are based on data from hundreds of thousands of other children, and indicate normal, near-normal and problematic development.
“Growth charts enable a family and their physician to quickly spot problematic development, and when necessary, intervene appropriately,” said team leader and psychiatrist Chandra Sripada, M.D., Ph.D.
“In the future, we want to provide clinicians with the same sort of guidance about brain development that we can about things like height and weight.”
Researchers launched the growth-charting concept after noticing a gap in the state of the science.
Lead author Daniel Kessler said, “We knew that the ability to sustain attention for an extended time increases dramatically during childhood and adolescence. We also knew that over the same time period, there are big changes in brain networks involved in attention.”
The insights led to the idea of growth charting as a way to test if these two patterns were related: Would children with underdeveloped brain networks also have more difficulty with attention?
To test the theory, researchers and colleague Michael Angstadt, M.A.S., used data from 519 children and teens who had genetic testing, brain imaging and tests of their cognitive development as part of the Philadelphia Neurodevelopmental Cohort based at the University of Pennsylvania.
The researchers created growth charts that reflected the configuration of what are called intrinsic connectivity networks, important units of functional brain organization. The way these networks interact may hold the key to healthy attention.
For example, one called the default mode network seems to be involved in daydreaming and inwardly focused thought, whereas another set of networks are involved in cognitively demanding tasks.
As we grow from children into adults, these two systems become more defined and separate, working in tandem like pistons: when one is on, the other turns off, explain the researchers.
But in children and those with attention difficulties, the “pistons” often misfire: The default mode network turns on and interrupts the other networks thereby interrupting attention.
Baseline data used in the attention growth chart was captured by using a standard test to measure attention functioning. The test asked children to respond to a sequence of letters and numbers on a computer screen.
The Michigan researchers then compared the brain development seen on the scans to attention functioning. It turned out they could actually predict how well a child would do on the attention test based on their place on (or off) the brain network growth chart.
The children with ADHD symptoms, and those with the lowest performance for their age on the attention tests, were the furthest off the curve of brain network development.
“These brain network growth charts show real promise,” said Sripada. “But they are far away from being ready for clinical use.”
The research used advanced MRI imaging, but Sripada and his colleagues hope to develop ways to track network maturity using less-expensive techniques such as electroencephalography, or EEG.
The next stage of research is already underway to see if the growth charting method will be useful in the Adolescent Brain Cognitive Development study (ABCD for short) that will involve 10,000 teens over several years.
“The ABCD study is unprecedented in size and provides a real chance to develop definitive growth charts for brain networks,” explained Sripada.
“We have the opportunity to understand how brain network development relates to a variety of outcomes, including cognition, emotion, personality, and behavior.”