A new study finds that adolescent brain development may play a critical role in whether a teenager is more likely to be involved in a car crash, the leading cause of injury and death among 16- to 19-year-olds in the United States.
The study discovered that slower growth in the development of working memory is associated with motor vehicle crashes, which points to cognitive development screening as a potential new strategy for identifying and tailoring driving interventions for teens at high risk for crashes, according to researchers at the Annenberg Public Policy Center of the University of Pennsylvania (APPC) and Children’s Hospital of Philadelphia (CHOP).
The researchers examined data from 118 kids in Philadelphia who were part of a larger group that participated in a six-wave survey from when they were 10- to 12-year-olds, in 2005, until they were 18- to 20-year-olds, in 2013-14. The survey measured working memory development, as well as associated risk-related traits and behaviors. This group later participated in a follow-up survey on driving experience.
“We found that teens who had slower development in working memory were more likely to report being in a crash,” said the lead author, Elizabeth A. Walshe, Ph.D., who is a postdoctoral fellow at the Annenberg Public Policy Center and at the Center for Injury Research and Prevention at CHOP.
Working memory, which develops through adolescence into the 20s, is a frontal lobe process associated with complex, moment-to-moment tasks essential to driving, she explained.
“Safe driving involves scanning, monitoring, and updating information about the vehicle and environment while managing multiple subtasks (e.g., adjusting speed, steering, in-vehicle controls) and distractors (e.g., peer passengers and cell phones),” the researchers said in the study, which was published in JAMA Network Open.
All of these tasks challenge working memory, especially when a young driver has not yet fully learned to automate many basic driving routines, the researchers noted.
Adolescent drivers have the highest rate of crashes, injuries, and mortality. While poor skills and inexperience explain some of the risk shortly after a new driver receives a license, crash risk is inversely related to age during the early years of driving, according to the researchers. In other words, among equally new drivers, those who are 17 years old have a higher crash rate than those who are 20 years old, which suggests a possible developmental link, they said.
“Not all young drivers crash,” Walshe said. “So we thought, what is it about those who are crashing? It could be related to variability in working memory development.”
Prior research has shown a link between lower working memory capacity and reckless and inattentive driving, crashes, and poor performance on simulated driving tasks.
For the new study, the researchers recruited participants from the Philadelphia Trajectory Study, a broad six-wave study conducted by researchers at APPC and CHOP. The study measured the change in working memory and other characteristics across seven years. Subsequently, in 2015, 118 young adults, including 84 drivers and 34 non-drivers, took the follow-up survey on driving. Among the drivers, 25 reported having a crash history and 59 reported no crash history.
The researchers discovered that young drivers whose trajectory of working memory growth was less-than-average in the group were more likely to report being in a crash. Drivers with greater-than-average growth in working memory were more likely to say they had not been in a crash.
The analysis controlled for other risk-related factors, including reckless driving and drug use, the researchers noted.
According to the researchers, the results have important policy implications. While all 50 states have some type of graduated driver licensing (GDL) program that gradually lifts restrictions for young new drivers, the research suggests that individual assessments of adolescents’ cognitive development may play an important part, too.
“If our findings hold up in larger samples with diverse youth, we will need to start assessing cognitive abilities, such as working memory, to see if some adolescents are less ready for independent driving,” said Daniel Romer, Ph.D., research director of the Annenberg Public Policy Center and a senior fellow at the Center for Injury Research and Prevention at CHOP. “There is considerable variation in working memory development during the teen years, and some teens may not be as ready to drive on their own without additional assistance.
“This research points to the fact that crashes are predictable and preventable,” added Flaura K. Winston, M.D., Ph.D., founder and scientific director of the Century for Injury Research and Prevention at CHOP. “It focuses attention more on the role of the driver and the driver’s clinician. A clinician could identify teens who will be at an increased risk and use ‘precision prevention’ to tailor anticipatory guidance so that young drivers achieve independent mobility in a safe way.”
Precision prevention could provide different types of driver training or a release from driving restrictions at different times based on their development, she noted.
According to the researchers, some form of standardized screening or testing during adolescence could determine which teens have slower development of working memory.
“Ideally, we’d be able to offer interventions like driver training or technologies like in-vehicle alert systems to assist new drivers who need it,” Walshe said.