Brain Science 1-7

Review paragraph 6. Which statement BEST summarizes the paragraph without personal opinions or judgments?

6 Laurence Steinberg has carried out many studies on risk-taking in this age group. In his excellent book Age of opportunity, Steinberg describes his compelling research on adolescence and his work with young people being prosecuted for dangerous decisions they have made, such as driving risks that have gone wrong. He argues that brain development, and the fact that risk-taking is a natural part of adolescent development, must be taken into account when considering whether an adolescent is guilty of a crime or not.

• Steinberg has carried out more studies on adolescence than Blakemore, the author of this book.

• Steinberg’s findings on adolescent behavior are the most compelling findings that have been published in recent years.

• Steinberg, a researcher who has studied risk-taking in adolescents, is trying to convince the public that adolescents should not be prosecuted for breaking the law.

• Steinberg, a researcher who has studied risk-taking in adolescents, argues that brain development should be considered when young people are accused of crimes.

Reread paragraphs 7–8. When the author states that “adolescents get a kick out of taking risks” (8), he means that these risks result in __________.

7 In the late 2000s, Steinberg, along with other researchers including B.J. Casey, proposed a theory to explain why risk-taking peaks in adolescence. Both Steinberg’s and Casey’s theories involve the brain’s limbic system, which (among other processes) generates the rewarding feeling—the kick—elicited by taking risks. The core idea is that, in young adolescents, the limbic system is already mature and particularly sensitive to the rewarding feeling that risk-taking sometimes elicits. At the same time, the prefrontal cortex—which stops us acting on impulse and inhibits risk-taking—is not yet mature, and will continue developing throughout adolescence and early adulthood.

8 The theory suggests that this results in a ‘developmental mismatch’ between the maturity and functioning of these two brain systems, and this in turn explains why adolescents get a kick out of taking risks (a function of the limbic system) and aren’t always able to stop themselves doing so in the heat of the moment (a skill that relies on the prefrontal cortex). In contrast, the theory suggests, adults are better at regulating behavior and stopping themselves taking dangerous risks, even when the risks are exciting and potentially rewarding, because of their mature prefrontal cortex. Steinberg called this the ‘dual systems model’ because of the two brain systems involved.

• a serious punishment

• a physical pain

• a positive emotion

• a financial boost

Which BEST represents the relationship between the limbic system and the prefrontal cortex in adolescence, according to Steinberg and Casey?

7 In the late 2000s, Steinberg, along with other researchers including B.J. Casey, proposed a theory to explain why risk-taking peaks in adolescence. Both Steinberg’s and Casey’s theories involve the brain’s limbic system, which (among other processes) generates the rewarding feeling—the kick—elicited by taking risks. The core idea is that, in young adolescents, the limbic system is already mature and particularly sensitive to the rewarding feeling that risk-taking sometimes elicits. At the same time, the prefrontal cortex—which stops us acting on impulse and inhibits risk-taking—is not yet mature, and will continue developing throughout adolescence and early adulthood.

• The mature limbic system usually has greater influence than the lessdeveloped prefrontal cortex.

• Both systems reward risk-taking, but one does so much more strongly.

• The prefrontal cortex often causes risk-taking behavior, but the limbic system rewards it.

• One system has started to function by this stage, but the other has not.

In paragraph 8, the author writes, “The theory suggests that this results in a ‘developmental mismatch’ between the maturity and functioning of these two brain systems, and this in turn explains why adolescents get a kick out of taking risks (a function of the limbic system) and aren’t always able to stop themselves doing so in the heat of the moment (a skill that relies on the prefrontal cortex).”

Which of the following examples BEST demonstrates the meaning of someone not being able to stop themselves from doing something in the heat of the moment?

• A shopper deciding to purchase one gift item instead of another

• A driver in a car with faulty brakes speeding out of control down a hill

• A person saying something they will later regret during an argument

• A boss firing an employee who was caught stealing from the business

Select the paragraph in which readers will find out why the author’s team performed their 2014 analysis on the question of adolescent brain development.

• Paragraph 7: In the late 2000s, Steinberg, along with other researchers including B.J. Casey, proposed a theory to explain why risk-taking peaks in adolescence. Both Steinberg’s and Casey’s theories involve the brain’s limbic system, which (among other processes) generates the rewarding feeling—the kick—elicited by taking risks. The core idea is that, in young adolescents, the limbic system is already mature and particularly sensitive to the rewarding feeling that risk-taking sometimes elicits. At the same time, the prefrontal cortex—which stops us acting on impulse and inhibits risk-taking—is not yet mature, and will continue developing throughout adolescence and early adulthood.

• Paragraph 8: The theory suggests that this results in a ‘developmental mismatch’ between the maturity and functioning of these two brain systems, and this in turn explains why adolescents get a kick out of taking risks (a function of the limbic system) and aren’t always able to stop themselves doing so in the heat of the moment (a skill that relies on the prefrontal cortex). In contrast, the theory suggests, adults are better at regulating behavior and stopping themselves taking dangerous risks, even when the risks are exciting and potentially rewarding, because of their mature prefrontal cortex. Steinberg called this the ‘dual systems model’ because of the two brain systems involved.

• Paragraph 9: These theories are based on the assumption that the brain’s reward and emotion systems mature earlier in adolescence than the prefrontal cortex control system. What is the evidence for this? Until recently there wasn’t much. So, in 2014 Kate Mills, AnneLise Goddings and I carried out an analysis in collaboration with Jay Giedd from the National Institute of Health in Bethesda to look at the question in a bit more detail.

• Paragraph 10: We returned to the MRI data from Jay Giedd and Judith Rapoport’s large developmental MRI study (see chapter 6). However, we weren’t able to include all the participants’ data in our analysis. This is because we needed MRI data from people who had been scanned at least three times, including once in late childhood, once in mid-adolescence and once in late adolescence/early adulthood, and not many people in Giedd’s sample had had at least three scans covering these age bands. Furthermore, because we were interested in the development of the limbic system, we needed brain scans that included high-quality images of these subcortical structures. That’s a challenge, as these small structures deep inside the brain (see illustration in chapter 4) can be blurred and distorted in MRI scans

Paragraph 12 states that the author’s team decided the sign of a mature brain region was that it had ceased ________.

12 We were interested in whether the limbic regions—specifically the nucleus accumbens, which processes reward, and the amygdala, which processes emotion—reach maturity earlier than the prefrontal cortex. We analyzed each of these regions in terms of the amount of grey matter it contained. In our study, a brain region was defined as ‘mature’ when its grey matter volume appeared to have stopped changing.

• growing

• changing

• aging

• reacting

Which of the following BEST describes the author’s purpose in writing this passage?

• To prove that Steinberg and Casey’s work left important questions unanswered

• To explain Steinberg and Casey’s theories and how her own team helped provide evidence for them

• To show how her own team’s evidence disproved Steinberg and Casey’s theories

• To argue that her team’s work was the foundation for theories that Steinberg and Casey later developed