CLBB Faculty Member Leah Somerville and her work on adolescent development are featured in the following article, which highlights the difficulty in determining a distinct line between adolescence and adulthood. Additional coverage about how her work intersects with the CLBB can be found here.

By Carl Zimmer | The New York Times | December 21, 2016

Leah H. Somerville, a Harvard neuroscientist, sometimes finds herself in front of an audience of judges. They come to hear her speak about how the brain develops.

It’s a subject on which many legal questions depend. How old does someone have to be to be sentenced to death? When should someone get to vote? Can an 18-year-old give informed consent?

Scientists like Dr. Somerville have learned a great deal in recent years. But the complex picture that’s emerging lacks the bright lines that policy makers would like. Continue reading »

By Matthew R. Peverill, Katie A. McLaughlin, Amy S. Finn, and Margaret A. Sheridan | Developmental Cognitive Neuroscience | February 16, 2016

Abstract:

While most measures of working memory (WM) performance have been shown to plateau by mid-adolescence and developmental changes in fronto-parietal regions supporting WM encoding and maintenance have been well characterized, little is known about developmental variation in WM filtering. We investigated the possibility that the neural underpinnings of filtering in WM reach maturity later in life than WM function without filtering. Using a cued WM filtering task (McNab & Klingberg, 2008), we investigated neural activity during WM filtering in a sample of 64 adults and adolescents. Regardless of age, increases in WM activity with load were concentrated in the expected fronto-parietal network. For adults, but not adolescents, recruitment of the basal ganglia during presentation of a filtering cue was associated with neural and behavioral indices of successful filtering, suggesting that WM filtering and related basal ganglia function may still be maturing throughout adolescence and into adulthood.

Read the full article here.

By BJ Casey, Adriana Galvan, and Leah Somerville | Developmental Cognitive Neuroscience | December 17, 2015

A hallmark of behavioral development is the increasing ability to suppress inappropriate, competing thoughts, desires, emotions and actions in favor of appropriate ones (i.e., self-control). One developmental phase that has received much attention in recent years is that of adolescence, due in part to the significant brain changes of this period (Lee et al., 2014) and also to the heightened risk for psychopathology and criminally relevant behaviors (Casey et al., 2015 and Cohen and Casey, 2014). Two interesting articles in this issue, by Shulman and colleagues and Nelson and colleagues, review the developmental science literature and describe potential models for understanding adolescent behavioral and brain development focusing largely on the importance of incentives and social influences, respectively, during adolescence.

Continue reading the full article here.

By Catherine A. Hartley and Leah H. Somerville | Current Opinion in Behavioral Sciences | October 3, 2015

Abstract:

Adolescence is a phase of lifespan associated with greater independence, and thus greater demands to make self-guided decisions in the face of risks, uncertainty, and varying proximal and distal outcomes. A new wave of developmental research takes a neuroeconomic approach to specify what decision processes are changing during adolescence, along what trajectory they are changing, and what neurodevelopmental processes support these changes. Evidence is mounting to suggest that multiple decision processes are tuned differently in adolescents and adults including reward reactivity, uncertainty-tolerance, delay discounting, and experiential assessments of value and risk. Unique interactions between prefrontal cortical, striatal, and salience processing systems during adolescence both constrain and amplify various component processes of mature decision-making.

Read the full article here.

By Elizabeth Kolbert | The New Yorker | August 31, 2015

C57BL/6J mice are black, with pink ears and long pink tails. Inbred for the purposes of experimentation, they exhibit a number of infelicitous traits, including a susceptibility to obesity, a taste for morphine, and a tendency to nibble off their cage mates’ hair. They’re also tipplers. Given access to ethanol, C57BL/6J mice routinely suck away until the point that, were they to get behind the wheel of a Stuart Little-size roadster, they’d get pulled over for D.U.I.

Not long ago, a team of researchers at Temple University decided to take advantage of C57BL/6Js’ bad habits to test a hunch. They gathered eighty-six mice and placed them in Plexiglas cages, either singly or in groups of three. Then they spiked the water with ethanol and videotaped the results.

Half of the test mice were four weeks old, which, in murine terms, qualifies them as adolescents. The other half were twelve-week-old adults. When the researchers watched the videos, they found that the youngsters had, on average, outdrunk their elders. More striking still was the pattern of consumption. Young male C57BL/6Js who were alone drank roughly the same amount as adult males. But adolescent males with cage mates went on a bender; they spent, on average, twice as much time drinking as solo boy mice and about thirty per cent more time than solo girls.

The researchers published the results in the journal Developmental Science. In their paper, they noted that it was “not possible” to conduct a similar study on human adolescents, owing to the obvious ethical concerns. But, of course, similar experiments are performed all the time, under far less controlled circumstances. Just ask any college dean. Or ask a teen-ager. I happen to have three adolescent sons and in this way recently learned about a supposedly fun pastime known as a “case race.” Participants form teams of two and compete to see which pair can drink its way through a case of beer the fastest. (To get the most out of the experience, I was told, it’s best to use a “thirty rack.”)

Every adult has gone through adolescence, and studies have shown that if you ask people to look back on their lives they will disproportionately recall experiences they had between the ages of ten and twenty-five. (This phenomenon is called the “reminiscence bump.”) And yet, to adults, the adolescent mind is a mystery—a Brigadoon-like place that’s at once vivid and inaccessible. Why would anyone volunteer to down fifteen beers in a row? Under what circumstances could Edward Fortyhands, an activity that involves having two forty-ounce bottles of malt liquor affixed to your hands with duct tape, be construed as enjoyable? And what goes for drinking games also goes for hooking up with strangers, jumping from high places into shallow pools, and steering a car with your knees. At moments of extreme exasperation, parents may think that there’s something wrong with their teen-agers’ brains. Which, according to recent books on adolescence, there is.  Continue reading »