ジャグリングを3か月練習したら脳の一部が大きくなった。でも、やめたら縮んでいった

Q1. What is the passage mainly about?

1. AHow to juggle five balls
2. BWhy muscles grow after exercise
3. CHow juggling practice changed the adult brain for a while
4. DWhy German people like juggling

ジャグリングの練習で灰白質が増え、やめると戻ったという話なので C。

Q2. What happened three months after the people stopped practicing?

1. AThe gray matter became smaller again.
2. BThe gray matter kept growing.
3. CThey could juggle better than before.
4. DTheir muscles became weaker.

three months after they stopped, the gray matter became smaller again とあるので A。

Q3. The brain "works a little like a muscle" because ...

1. Ait can lift heavy things
2. Bit grows with use and shrinks without use
3. Cit is made of muscle cells
4. Dit gets tired after juggling

練習すると増え、やめると減る＝筋肉と同じく「使えば増え、使わなければ減る」という意味なので B。

Q1. How many people practiced juggling in the 2004 study?

1. A12
2. B24
3. C60
4. D7

24人を2組に分け、そのうち12人が練習したので A。24は参加者全体の数。

Q2. According to later studies, which statement is true?

1. AOnly young people showed brain changes.
2. BChanges took at least one year to appear.
3. CRepeating an old skill was more important than learning a new one.
4. DChanges could appear after just seven days of training.

even after just seven days of training とあるので D。60歳前後でも変化があり、新しく覚えることのほうが大切とされている。

Q3. What can an MRI scan NOT tell us, according to the passage?

1. AWhether a region looks bigger
2. BWhether the change comes from new cells, more branches, or blood flow
3. CHow many people took part in the study
4. DWhich area processes visual motion

It cannot tell whether the change comes from new cells, more branches, or blood flow とあるので B。領域が大きく見えることは MRI でわかる。

Q1. Which statement best describes the passage?

1. AIt proves that juggling increases intelligence.
2. BIt argues that the adult brain cannot change.
3. CIt explains why gray matter is gray.
4. DIt shows that skill learning can change brain structure, while pointing out the limits of the evidence.

練習で脳構造が変わることを示しつつ、MRI の限界や研究デザインの弱点などの問題も指摘しているので D。

Q2. What does "transient" most likely mean in the passage?

1. APermanent
2. BTemporary
3. CDangerous
4. DInvisible

直後に Once practice stopped, the gain partly reversed とあり、増加が一部元に戻ったことから、transient は「一時的な」の B。

Q3. Why should the MRI results be read carefully?

1. ABecause MRI cannot tell which tissue change caused the increase in volume
2. BBecause the participants already knew how to juggle
3. CBecause the scans were taken only once
4. DBecause hMT/V5 has nothing to do with vision

MRI estimates volume but cannot distinguish between more neurons, extra dendrites ... とあるので A。