A window on adolescence | U Daily
Photo by Kathy F. Atkinson
September 03, 2020
As any parent will tell you, no two children behave exactly the same. It’s part of what makes each individual unique.
So why do some teens take more risks than others?
Biomedical Engineer from the University of Delaware Curtis Johnson and graduate student Grace McIlvain think they have an idea.
The part of the brain that makes teens want to take risks is called the socio-emotional system. The brain’s cognitive control center, on the other hand, helps prevent teens from acting on these impulses.
In a recent post paper in NeuroImage, Johnson and McIlvain suggest that these two brain centers physically mature at different rates and that adolescents with large differences in the rate of development between these two brain regions are more likely to take risks. Additionally, the research team theorizes that it is the basic structure of the brain that drives these tendencies to risk taking and control.
What makes this study unique is that researchers at UD and their collaborators used a technique called magnetic resonance elastography (MRE) to safely measure the mechanical properties of brain tissue as a measure of the development of the brain. brain, rather than the activation of these two regions.
Elastography is a method of imaging the mechanical properties of tissues using a magnetic resonance imaging (MRI) scanner. Put simply, the researchers take snapshots of how the brain warps – or bends – when it vibrates at a low frequency, and then subject those images to a specific algorithm to reverse the engineering of what’s going on. Johnson explained that the MRE vibration is safe for all ages and provides less movement than what occurs naturally in the brain. It also offers less vibration than other devices designed for children, such as vibrating rockers.
Johnson compared the process to any other material test and said the research team’s knowledge of how tissue deforms helps them interpret what is happening under different vibrations. In adults, MRE techniques have become popular for studying diseases, such as Alzheimer’s disease, with research showing relationships between memory and cognitive performance.
“MRE techniques are not a substitute for other aspects of studying brain development, but they can provide a more sensitive and objective way to examine brain wiring,” said Johnson, assistant professor at Department of Biomedical Engineering.
Mapping adolescent brain development
This is not the first time that researchers have examined how two regions of the brain interact to form a certain outlet. But most of this work was done using a functional MRI (fMRI), where study participants are placed in the scanner and given a task in real time, and the researchers observe which areas of the brain light up to determine which areas of the brain are linked. to this task.
Johnson’s research group was one of the first to use ERM techniques to create high-resolution three-dimensional maps that allow scientists to examine specific regions of the brain. The intensity of each 3D pixel in an image makes sense. For example, bright colors indicate high stiffness, which in this case indicates a measure of developmental maturity.
Examining these characteristics of the brain in their work, the researchers found that it was not just the center of socio-emotional or cognitive control, but the combination of the two brain centers working together at a specific age or time that was the determining factor in risk taking.
“So there’s that time during the teenage years when the part of the brain that makes you want to take risks is more mature than the part of the brain that suppresses those impulses,” said McIlvain, who started working on the project as an undergraduate student. researcher in 2016 and is now a doctoral candidate in the third year of biomedical engineering.
“If we can identify the individuals most likely to take risks, based on the biological makeup of their brains, or perhaps groups of individuals, this could inform prevention strategies. “
Prior to this project, little research on MRE had measured cerebral stiffness in children. Previous work in 2018 by McIlvain showed that the outside of the brain feels softer in teens than adults, while the inside of the brain feels stiffer in teens than adults. According to Johnson, this fits the known developmental trajectory where the inside of the brain develops first and the outside, the cortex, develops later.
The work grew out of Johnson’s previous collaborative research with Eva Telzer, professor of psychology at the University of North Carolina and co-author of the article, and takes advantage of the UD’s advanced MRI capabilities. Biomedical and brain imaging center. Today, researchers at the Johnson Lab are developing all aspects of this MRE technique, from how to safely vibrate the head in the scanner, to how to write the software to acquire the data to the methods to transform the data in images which are translated into mechanical properties.
While the research team’s previous work has shown differences in brain function in typically developing children and those with diseases, such as cerebral palsy, this is the first time that researchers have shown a relationship with function in healthy children. But there are still more questions than answers.
For example, Johnson said there is currently no good metric for telling when the brain is mature or even for defining brain health. And while the research team has made links between the rigidity of the adolescent brain’s socio-emotional system and the cognitive control center interacting and supporting risk-taking, there are other things that they do. don’t know, like how these regions of the brain are affected by things like socioeconomic status, early life trauma or early education.
One of the main goals of the work is to speed up MRE analysis. The scan currently takes more than six minutes, which can be difficult for children with disabilities or very young.
“We would like to complete the analysis in less than a minute – less time than a half a song from a Disney movie – before a child loses interest and thinks about moving,” Johnson said.
The next steps in the research are to scan children as young as 5 years old, including those with autism. The hope is to create a robust data set to explore how the mechanical properties of the brain change from ages 5 to 30, generally considered late adolescence. Among other things, they hope to use this data to better understand how children with disabilities fit into this developmental curve.
“At this time, there is no standard way to diagnose autism, no targeted treatment plan, or metric to measure whether the intervention is helping,” said McIlvain, who recently received a National Fellowship. Institutes of Health to study stiffness in the brain in children with autism. “If we can understand how the mechanical properties of the brain are affected in an autistic person, we can begin to answer some of these questions.”