Study Aims to Find Out Why Some People Are Left-handed

2024-04-10

00:00 / 00:00
复读宝 RABC v8.0beta 复读机按钮使用说明
播放/暂停
停止
播放时:倒退3秒/复读时:回退AB段
播放时:快进3秒/复读时:前进AB段
拖动:改变速度/点击:恢复正常速度1.0
拖动改变复读暂停时间
点击:复读最近5秒/拖动:改变复读次数
设置A点
设置B点
取消复读并清除AB点
播放一行
停止播放
后退一行
前进一行
复读一行
复读多行
变速复读一行
变速复读多行
LRC
TXT
大字
小字
滚动
全页
1
  • What do Lady Gaga, Barack Obama, and Bill Gates have in common - aside from their fame? They are all left-handed.
  • 2
  • But why are 10 percent of people left-handed while most are right-handed?
  • 3
  • Researchers are trying to find out.
  • 4
  • A recent study identified a genetic cause of left-handedness in some people.
  • 5
  • Researchers found rare variants of a gene involved in controlling the shape of cells.
  • 6
  • They found the variants to be 2.7 times more common in left-handed people.
  • 7
  • These genetic variants account for possibly 0.1 percent of left-handedness.
  • 8
  • But the researchers said a gene, called TUBB4B, might play a part in the development of brain asymmetry.
  • 9
  • In most people, the two halves, or hemispheres, of the brain have slightly different structures and are dominant for different activities.
  • 10
  • "For example, most people have left-hemisphere dominance for language, and right-hemisphere dominance for tasks that require directing visual attention to a location in space," said Clyde Francks of the Max Planck Institute for Psycholinguistics in the Netherlands. Francks was the top writer of the study published recently in Nature Communications.
  • 11
  • Francks suggested that for most people, the left side of the brain controls the dominant right hand.
  • 12
  • "The nerve fibers cross from left-to-right in the lower part of the brain," Francks said.
  • 13
  • He added, "In left-handers, the right hemisphere is in control of the dominant hand.
  • 14
  • The question is: what causes the asymmetry of the brain to develop differently in left-handers?"
  • 15
  • TUBB4B controls a protein that gets formed into filaments called microtubules.
  • 16
  • These microtubules give structure to the insides of cells.
  • 17
  • The changes in TUBB4B that are more common in left-handers suggest that microtubules are involved in setting up the brain's normal asymmetries, Francks said.
  • 18
  • The two brain hemispheres start to develop differently in the human embryo. Scientists do not know the mechanism that controls this.
  • 19
  • "Rare genetic variants in just a handful of people can pinpoint genes that give clues to developmental mechanisms of brain asymmetry in everyone," Francks added. TUBB4B is an example.
  • 20
  • The study's findings were based on genetic data from more than 350,000 middle-aged to older adults in Britain.
  • 21
  • It was from the UK Biobank. About 11 percent of the people involved were left-handed.
  • 22
  • For most people, left- or right-handedness might come down to chance.
  • 23
  • Changes in the levels of some molecules during important times of brain development could influence it, Francks suggested.
  • 24
  • Historically, many cultures disapproved of left-handedness and forced people to become right-handed.
  • 25
  • In English, the word "right" also means "correct" or "proper." And the expression a "left-handed compliment" means that a comment might seem nice but is an insult.
  • 26
  • The levels of left-handedness differ around the world, with lower rates in Africa, Asia and the Middle East compared to Europe and North America, Francks said.
  • 27
  • "This likely reflects suppression of left-handedness in some cultures - making left-handed kids switch to right-handedness, which also used to happen in Europe and North America," Francks added.
  • 28
  • The new findings might have use in the field of mental health.
  • 29
  • People with schizophrenia are around twice as likely to be left-handed or ambidextrous.
  • 30
  • People with autism are around three times as likely, Francks said.
  • 31
  • He observed that genes involved in developing the brain in early life might be involved in brain asymmetry and mental health.
  • 32
  • "Our study found suggestive evidence of this, and we have also seen it in previous studies where we looked at more common genetic variants in the population," Francks added.
  • 33
  • I'm John Russell.
  • 1
  • What do Lady Gaga, Barack Obama, and Bill Gates have in common - aside from their fame? They are all left-handed.
  • 2
  • But why are 10 percent of people left-handed while most are right-handed?
  • 3
  • Researchers are trying to find out.
  • 4
  • A recent study identified a genetic cause of left-handedness in some people. Researchers found rare variants of a gene involved in controlling the shape of cells. They found the variants to be 2.7 times more common in left-handed people.
  • 5
  • These genetic variants account for possibly 0.1 percent of left-handedness. But the researchers said a gene, called TUBB4B, might play a part in the development of brain asymmetry.
  • 6
  • In most people, the two halves, or hemispheres, of the brain have slightly different structures and are dominant for different activities.
  • 7
  • "For example, most people have left-hemisphere dominance for language, and right-hemisphere dominance for tasks that require directing visual attention to a location in space," said Clyde Francks of the Max Planck Institute for Psycholinguistics in the Netherlands. Francks was the top writer of the study published recently in Nature Communications.
  • 8
  • Francks suggested that for most people, the left side of the brain controls the dominant right hand. "The nerve fibers cross from left-to-right in the lower part of the brain," Francks said. He added, "In left-handers, the right hemisphere is in control of the dominant hand. The question is: what causes the asymmetry of the brain to develop differently in left-handers?"
  • 9
  • TUBB4B controls a protein that gets formed into filaments called microtubules. These microtubules give structure to the insides of cells. The changes in TUBB4B that are more common in left-handers suggest that microtubules are involved in setting up the brain's normal asymmetries, Francks said.
  • 10
  • The two brain hemispheres start to develop differently in the human embryo. Scientists do not know the mechanism that controls this.
  • 11
  • "Rare genetic variants in just a handful of people can pinpoint genes that give clues to developmental mechanisms of brain asymmetry in everyone," Francks added. TUBB4B is an example.
  • 12
  • The study's findings were based on genetic data from more than 350,000 middle-aged to older adults in Britain. It was from the UK Biobank. About 11 percent of the people involved were left-handed.
  • 13
  • For most people, left- or right-handedness might come down to chance. Changes in the levels of some molecules during important times of brain development could influence it, Francks suggested.
  • 14
  • Historically, many cultures disapproved of left-handedness and forced people to become right-handed.
  • 15
  • In English, the word "right" also means "correct" or "proper." And the expression a "left-handed compliment" means that a comment might seem nice but is an insult.
  • 16
  • The levels of left-handedness differ around the world, with lower rates in Africa, Asia and the Middle East compared to Europe and North America, Francks said.
  • 17
  • "This likely reflects suppression of left-handedness in some cultures - making left-handed kids switch to right-handedness, which also used to happen in Europe and North America," Francks added.
  • 18
  • The new findings might have use in the field of mental health. People with schizophrenia are around twice as likely to be left-handed or ambidextrous. People with autism are around three times as likely, Francks said.
  • 19
  • He observed that genes involved in developing the brain in early life might be involved in brain asymmetry and mental health.
  • 20
  • "Our study found suggestive evidence of this, and we have also seen it in previous studies where we looked at more common genetic variants in the population," Francks added.
  • 21
  • I'm John Russell.
  • 22
  • Will Dunham reported on this story for Reuters. John Russell adapted it for VOA Learning English.
  • 23
  • _____________________________________________
  • 24
  • Words in This Story
  • 25
  • variant - n. different in some way from others of the same kind
  • 26
  • asymmetry - n. having two sides or halves that are not the same
  • 27
  • dominant -adj. having the most control, strength or ability to influence
  • 28
  • fiber -n. a long, thin piece of material that has strength to it
  • 29
  • filament - n. a long thread made of proteins
  • 30
  • mechanism - n. a process or system produces a particular result
  • 31
  • ambidextrous - adj. able to use both hands equally well