Area parents and educators received a new explanation last week for their teenagers' messy backpacks and reckless behavior in the latest brain science.
McLean Hospital neuroscientist Marisa Silveri visited Hingham High School with slides of pecan-shaped teenage brains splattered with Jackson Pollock-like dashes of color, and began translating her raw scientific data into clues that she said can help parents understand the mysteries of teenage behavior, whether it's the recent bomb threats at Cohasset High School that led to the arrest of a 13-year-old suspect, the vehicular homicide of a Bridgewater State College student allegedly by another student driving while drunk, the rising high school dropout rate in the state, or the growth of a ''Generation Rx,” young people abusing addictive prescription drugs.
''If science stops at the door of the laboratory, we're not doing what we should,” said Silveri, who gives plain-language talks about brain science to help the average parent understand why youngsters don't think the same way as adults, and to reveal in the process that even the most thuggish-looking teens have brains that are as vulnerable as an infant's.
Parents and teachers from 25 area schools attended the event, hoping for everything from insight into what makes their youngsters tick to a reminder that even though some youths look like adults, their brains are still in a crucial phase of rapid maturation. The presentation, part of the South Shore Hospital's 11-year-old Adolescent Suicide Prevention Project, is aimed at demystifying adolescence for parents and teachers. Organizers said they hope to follow up with a similar program to give teens insight into their own behaviors.
Silveri showed pictures of teenage and adult brains while each performed such simple tasks as naming colors or reacting to pictures of calorie-rich desserts. The images revealed, time and again, that teenage and adult brains are wired differently, using opposite circuits to react to a slab of chocolate cake, or to consider more complicated dilemmas.
The philosophy of the program, as summed up by Braintree teacher Diane Radigan, is simple: ''A lot of people write [bad behavior] off as being normal in the teenage years . . . but it's sort of like if your car's not working. You have to understand how” the car, or the teenage brain, functions in order to develop a strategy for dealing with a problem.
Silveri's images showed striking examples of the differences between adult and teen thought processes. When teenagers were asked to stare at pictures of fearful faces, splotches of color lighted up in a part of the brain that processes gut reactions and primitive emotions. Adults, on the other hand, used a part of the brain that is responsible for weighing consequences and making decisions, the frontal lobe. Teenagers, unlike adultsdid not identify the emotion they saw as fear.
''Our jobs as adults is to serve as external frontal lobes,” said Barbara Green, a psychologist who teamed with Silveri to help explain how brain science could help shape parenting techniques. ''Teenagers are these emotionally pulsating creatures,” so adults have to be steady to guide them, even sometimes doing the work of the frontal lobe by bombarding them with hypothetical situations: If a teen goes to the mall to hang out with her friends, what will happen to her homework?
The adults in the audience also got to test the strengths of their own frontal lobes. Asked to say the color they saw projected on the screen, the audience got tripped up in the last round. When the color red appeared on the screen as a red-colored font, it also spelled out the word ''green” or ''blue.” Asked to say one color while reading another, adults did the task more slowly, and stumbled more often. But give a group of teenagers the exact same task, and it would take even longer and yield more mistakes because, Silveri said, children have more trouble suppressing the wrong answer.
To do the task correctly, ''we need the part of the brain that inhibits incorrect responses . . . but [that area] is just starting to rev up during adolescence,” Silveri said.
Teenagers' brains aren't getting bigger as they grow: The brain cells, called neurons, are simply rearranging, making new connections, and pruning unnecessary ones to speed and reroute the flow of thought.
Barbara Levin, a Hingham parent who described her teenage daughter as ''spirited,” said that as a nurse at Massachusetts General Hospital she had seen college students after they had fallen out of dorm windows, or been involved in car crashes, or even ''car surf” — stand on the hood of a car moving at high speed — with deadly results.
Knowing what could happen when the frontal lobe was damaged, Levin said, she was eager to understand what happened during development too.
''I remember thinking 'I don't know why I did that' when I was a teenager,” said Lesley Sherman, a Hingham mother of two teenagers. ''Now I know: It was my brain developing.”
After describing the emotional roller coaster of being a parent to youngsters who often seem overtaken by ''temporary insanity,” Sherman looked at the notes she made on her program.
''I am the frontal lobe for my teen,” she recited.