Warning! Junk foods can harm a teen’s brain

Read the section "Brains Under Construction." Select the paragraph from the article that suggests specific regions of the brain can perform multiple functions.

• Let's break that down, starting with preteen and teen behaviors. The brain region that tells us we shouldn't eat chips all the time — and helps us resist that urge — is the last to mature. Called the prefrontal cortex, this region doesn't fully develop until we are in our early 20s.
• "Most of our complex brain functions happen in the prefrontal cortex," says Reichelt. This includes complex math and reading, but she notes that it also includes "how to assess risky behavior."
• In fact, these regions are even more sensitive when we are young. That's because of a natural chemical called dopamine. Dopamine is sometimes called the "feel good" chemical, and it lifts our mood when we experience something rewarding. And it is especially active in adolescent brains.
• The teen brain, thus, has two strikes against it when it comes to resisting junk food. "It has a heightened drive for rewards and reduced self-regulation," says Reichelt.

Which sentence in the section "Mouse Brains On Fat And Sugar" BEST supports the inference that unhealthy diets can affect a mouse's ability to survive?

• One group of mice ate a diet in which 63 percent of their calories came from fat.
• Mice will naturally explore their environment and are drawn to new things.
• To get out of the water, a mouse must navigate to the platform by remembering landmarks.
• The fatter mice were just as good at swimming; they just did not find their way to the platform.

Read the following sentence from the article. Adolescents have more dopamine receptors in the brain than do adults, so they get more good vibes from anything they find enjoyable. HOW does this detail develop the article’s central idea?

• It explains why teenagers have difficulty controlling impulsive behaviors.
• It describes why adults have fewer dopamine receptors than do adolescents.
• It emphasizes that processed foods can have a negative impact on dopamine.
• It contrasts dopamine with other types of neurotransmitters in the brain.

Which sentence from the article would be MOST important to include in a summary of the article?

• She and two other researchers at Western recently reviewed more than 100 studies (including their own) about how poor food choices can impact adolescent brains.
• That's a big problem for adolescents because of the third issue: Growing brains can be more easily changed by eating high-fat, high-sugar foods.
• For example, working memory helps you remember which five things you need to buy at the store.
• People with brain diseases (such as schizophrenia and bipolar disorder) often have lower levels of reelin, too, says Reichelt.

Write a short paragraph that explains the central idea of the article. Use at least two details from the article to support your response.