Brain Matters


It’s too bad that the actual mechanical work of doing it is so hard. Wouldn’t it be nice to open up the hood and add a few extra gigs of memory to our rapidly depleting supply? And why can’t our brain’s IT guy clean out the nagging flashbacks of those idiotic things we once did, the events we now breezily refer to as our “questionable decisions”?

These questions go triple for anyone who is raising a teenager. While the dutiful parent contends with a mixture of joyous wonderment and seething exasperation, he or she knows that their teenager’s brain is probably similarly vexed, if not a berserk carnival of conflicting emotions.

A decade ago, Frances Jensen was like any other mother raising teenage sons and demanding to know “What is going on?” But she had the advantage of some extra information. A Greenwich Academy graduate, she was running the neurology research lab at Harvard and thus understood as well as anyone that the brain is not a patchwork of wires and fuses. It is more like 100 billion neurons banging into each other and making connections in 100 trillion synapses. So, uh, handle with care.

Through the fresh waves of scientific instruments that have lately become available, Dr. Jensen is privy to this mysterious wonderland of the brain. She has seen firsthand how the brain’s capacities are altered by outside forces. She was pursuing the mechanical forces that lead to things like epilepsy when she took a look at her life and realized something important. “I had another experiment going on in my own house, which was my two teenage sons. I was thinking of this whole thing in awe, in that changes were happening so fast and they were unrecognizable in a lot of ways. I was a single parent at the time and didn’t want to make a mistake. So I took what could have been anger and frustration and turned it into curiosity.”

Dr. Jensen radiates a speed of thought. Sitting in an office at Greenwich Academy, where she has come to talk with students privately and deliver an evening lecture to parents, the smartly dressed woman with medium-length blond hair talks in a rapid-fire clip that must be a challenge for any note-takers. Besides the lectures, she is promoting the results of her findings in her book,
The Teenage Brain: A Neuroscientist’s Survival Guide to Raising Adolescents and Young Adults.

When she first threw herself into the literature on the young and the restless, she was disappointed to find titles that mocked the teenage brain and referred to its owners as an alien species. “These are people, too,” she reasoned, “and they’re trying to find out who they are.”

To be sure, in the last two decades a lot of parents have jumped on the Baby Einstein theories that by stimulating infants in the crib, they’ll end up class president. The problem might well be that once those gorgeous babies turn into sullen, risk-taking teenagers, they come to be regarded more as Baby Dillingers.

Dr. Jensen wants you to think. With a missionary’s zeal she leads you into her world and demands that you see the adolescent’s mind for what it actually is—plastic, pliable, endlessly adaptable, not yet stitched together, a veritable learning machine that can consume fresh information at a rate it will never have when its owner is a wised-up adult.

Once Dr. Jensen has painted this portrait of the wondrous teenage brain, she gets around to that now-crucial subject: How is this wonderful cranial computer affected by, oh, pot-smoking? And this is where Jensen’s sunny disposition goes dark.

She grew up in a home that prized knowledge. “My mother had been in British intelligence during World War II, so she was a force to be reckoned with when it came to pulling a fast one on her. ‘Where are you?’ ‘I’m at the library.’ ‘No, you’re not! I heard a car beep, you’re outside, where are you?’

“My family was very square compared to other families. My parents are from England and Denmark, and they moved here to Greenwich just after my dad’s medical training. He is a urologist, long retired.”

She calls herself a Greenwich Academy “lifer,” beginning there at age four and continuing through high school graduation. In her teenage years, she bonded with her father over their shared love of science. He would come home, fix a martini and review her geometry theorems.

One summer, at a teacher’s suggestion, she worked at the Greenwich Association for Retarded Children and often noticed how well the impaired kids functioned. But she really noticed the benefits of the Greenwich lifestyle when she attended college at Smith and worked down the road at Belchertown State School for the Feeble-Minded, a ghastly hospital (now shuttered) where low-functioning kids were essentially warehoused.

“Nature-versus-nurture if I ever saw it. I said, ‘That’s it, I’m going to research how environment changes the brain.’” Off she went to Cornell Medical School, followed by a residency at Harvard. When Penn offered her the chair of Department of Neurology in 2012, she accepted but insisted on still having a lab.

It is in the modern laboratories where the evidence spills in cataracts of new information on what goes on inside the growing noggin. “We now have the technology to understand the body’s most complex organ,” she says urgently. “It’s game-changing on so many levels.” It’s not just about comprehension. Adding together dementia, epilepsy, autism and other conditions, she says that “the most dominant source of medical disability is in the brain and nervous system.”

The pace of efforts to map the brain is fifteen years behind oncology, she says, but is poised to zoom ahead as new discoveries are being made in the world of MRIs and computer interfaces. The hidden circuits are gradually being revealed. “Our understanding of the brain is expanding at an exponential rate because of the technology we have for imaging and genomics. I think we’re now able to identify more dysfunction of behavior more as disease, because it can be diagnosed via brain mapping that we didn’t have before.”

Do not think of this thing inside a kid’s head as some sort of whirling, burgeoning computer, but rather as living tissue that can grow and expand like a muscle.

For a long time, Dr. Jensen says, pediatric authorities figured that a child’s IQ was pretty much set at the start. Even the pioneering developmental psychologist Jean Piaget, she thinks, made a fundamental error. “His developmental timeline ended at twelve. He said the complex cognition was there. That’s when you pay for adult tickets at fairs. So for years people stuck with twelve because that’s when puberty starts.

“But adolescents are not adults with fewer miles on them. They are only probably eighty percent of the way there. And there’s this remarkable period ahead of them in which they are dynamically changing in response to the environment. Actually even your IQ can change in that window.

“Teenagers have strengths they’ll never have again. And they have weaknesses that will pass. It’s kind of a double-edged sword.” Parents know this all too well. It’s nice that the kids are so smart, but why do they suddenly want to walk a tightrope over Niagara Falls?

Why? Because of the way their brains mature. Dr. Jensen runs her hand from the back of her neck to her forehead to show the path of a brain’s development. While the visual and motor areas get up to speed early, the final zone to get connected is literally up front—the frontal lobes. “That’s your executive area: impulse control, empathy, decision-making. Your limbic system is well on-board by your mid-teens, hence peer pressure overriding logic. But your frontal lobe is not there to say, ‘Don’t do that, bad idea.’

“So there’s biology behind why they are novelty-seekers and risk-takers. People have likened this to a Ferrari with weak brakes. Going straight ahead full blast and powerfully. So they learn faster than they ever will at any time in life.” It is, however, critical to learn things that make them stronger. To be brutally Darwinian about it, they could learn to go bad.

“I tell kids, ‘Mind your brain now and it will mind you later.’ Your IQ can change a lot in your teen years. A third of the people go up and a third of the people go down.

“Now we’re beginning to know, through functional imaging and other advanced technology, what makes it go up and what makes it go down. And substance abuse like cannabis use drops your IQ and drops the thickness of your brain as well. A critical thickness is associated with your IQ, and you can watch it grow or not grow.”

All that massive brain activity makes binge-drinking an especially dangerous habit. Teen brains are more vulnerable—there is simply more real estate to get poisoned.

Then there is the recent trend toward the decriminalization of pot, which might have some unfortunate side effects, if you will.

“They never asked the doctors what they thought about legalizing pot,” she frowns. “The science around cannabis is still poorly understood. The jury is still out on what it does to an adult brain, although studies show that chronic use reduces verbal memory performance.” Her eyes start blazing. “As for chronic use in adolescence, every piece of data shows a dose-dependent drop in IQ, a thinning of the white matter, a drop in brain growth, which has long-lasting effects. It’s like growing a tree. If you stunt it, you’re never going to get the big plume in the area where that big branch would have been.”

When she talks with the students, she is clear about laying all this out in a matter-of-fact manner. She is happiest when the kids’ response is something like, “Oh, now I get it!” Because there it is: Repetition leads to the creation of bigger synapses, which can lead to creation of knowledge—or habit.

“Addiction is a form of learning,” she sighs. “They can learn harder, faster, stronger, and they can get addicted harder, faster, stronger. They need to know that.”

There are, naturally, various business interests who’d like to know more about these new maps to human behavior. If we knew how the teen brain works, we could sell ’em something! When she did an address at Wharton, she picked up on the strong curiosity about how knowledge of the adolescent brain might lead to more effective advertising. She blanched at the thought. “If there’s a Hippocratic oath for advertising, I want to take it right now. Don’t use this information in a way that is deleterious to this group in society.”

More worrisome is what she sees abroad with the likes of ISIS. Part of her work is with UNICEF, where there is considerable study of adolescents involved in terrorism. “Extreme stress in your adolescence can raise the risk of depression. It sort of rewires your brain.” In parts of the world visited by constant suspicion and bombing, these rewired brains are everywhere on the loose.

“That’s their environment and they’re imprinting on that environment. They might seem mature, but they’re probably developing their brains one way for survival and they’re missing whole normal development stages. This is all unknown, but it can be studied. What is the effect of stress in this seven-year window of development? And what kind of person comes out at the end of it? And how reversible is that?”

This is an area worthy of profound study even outside the foothills of Iraq. Dr. Jensen believes that as many as one in four people have some sort of psychiatric condition, ranging from anxiety up to severe affective disorders like schizophrenia. “Yes, one in four,” she maintains, “and if you look at people with severe illness, between sixty and eighty percent had the onset between the ages of sixteen and twenty-five. You hear about the spate of suicides in college and people having psychotic breaks in high school—it’s not the stress of college and high school, it’s the biology.

“Sadly, it’s also a time when your peers, because their frontal lobes are not fully in line, are not very empathetic. And you are more isolated because of the [mental illness] stigma.”

Giving her some hope is the knowledge that science is now paying attention to the big picture and not just tiny areas of specialization. When she gave a lecture on the subject to 4,000 members of the Society for Neuroscience in San Diego, she got a great response. “A lot of card-carrying neuroscientists don’t know this. You get siloed into one area. It’s kind of fun to do this thing that crosscuts from genes to molecules to behavior, all across the adolescent brain.”

Indeed, there is now a field of study called Connectomics, which seeks to look for connections within the organism. “The connectome is the new way to think about the brain. It used to be like the six blind men with the elephant. Now we’re seeing how the whole brain works in concert.”

When parents ask what they can do to get their kids a head start, as they did later that night in a packed Greenwich Academy theater, Dr. Jensen points out the value of giving kids a wide variety of experience. “Because of genetic variation they will be better at some things than others. You’re already going to be wired in some ways. But unless you get exposed to a wide range of things you’ll never get a chance to experiment with that thing where your genes are giving you the advantage. So hopefully a childhood should be filled with a lot of breadth. Not depth, necessarily, but breadth. Because you’ll pick up where the kid seems to excel and you’ll know the area you could build depth in.

“This is where child prodigies come from—practice, practice, practice. You’ll never be able to gain that much expertise as an adult. Because of this plasticity that exists.”

In days gone by, people wondered about things like being a “left brain or right brain” personality. Dr. Jensen doubts there is any biological basis for that but does think we should know whether we are visual learners, verbal learners, or whatever, all the better to discover our skill sets during this critical period.

There is, in fact, much to learn about brain growth. But it’s going to be more recognized as a necessary thing. She can only smile broadly: “We’ll probably have an app for that in the next ten years.”



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