Jet Lag and the Brain

54 时差对大脑的影响

DATE=6-6-01
TITLE=SCIENCE REPORT- Jet Lag and the Brain
BYLINE=Nancy Steinbach

(Start at 59")This is Steve Ember with the VOA Special English Science Report.
A new study says one part of the human brain may become smaller as the result of a condition known as (1) jet lag.  Jet lag results from flying long distances in an airplane.  Jet lag interferes 1 with a person's normal times for sleeping and waking.  People with jet lag may feel extremely tired for several days.  They also may have problems thinking clearly and remembering.
Kwangwook Cho is a researcher at the University of Bristol in Britain.  He reported the findings of his jet lag study in the publication Nature (2) Neuroscience. 
The study involved twenty young women who worked for international airlines.  The women had served passengers on airplanes for five years.  These flight attendants flew across many countries and at least seven time zones. 
In the study, the flight attendants had different amounts of time to recover from jet lag.  Half the women spent five days or fewer in their home areas between long flights.  The other half spent more than fourteen days in their home areas.
Mister Cho took some fluid from the women's mouths to measure levels of a (3) hormone 2 that increases during stress. He tested them to see if they could remember where black spots appeared on a computer screen.  And he took pictures of their brains using (4) magnetic (5) resonance 3 (6) imaging.  This is a way to measure the size of the brain's (7) temporal (8) lobes 4. 
Mister Cho found that the women who had less time between flights had smaller right temporal lobes. This area of the brain deals with recognizing and remembering what is seen.  The same group performed worse and had slower reaction times on the visual memory test.  And their (9) saliva 5 samples showed higher levels of stress hormones 6.
Mister Cho says he believes the brain needs at least ten days to recover after a long trip.  He says airline workers told him their ability to remember got worse after working on planes for about four years. Other studies have shown that increased feelings of stress can cause a loss of cells in the part of the brain that controls memory. 
Scientists say more tests are needed to study the effects of jet lag on the brain.  They want to find out if too much jet lag could (10) permanently 7 affect memory. 
This VOA Special English Science Report was written by Nancy Steinbach.
This is Steve Ember.

(1) jet lag n. 时差
(2) neuroscience [9njUErEU`sai[ns] n.神经系统科学( 指神经病学、 神经化学等)
(3) hormone [ `hR:mEUn] n.荷尔蒙, 激素
(4) magnetic [mAg`netik] adj.磁的, 有磁性的, 有吸引力的
(5) resonance [ `rezEn[ns] n.共鸣, 回声, 反响, 中介
(6) imaging [i`mAdViN] [计] 成像
(7) temporal [ `temp[r[l] adj.时间的, 当时的, 暂时的
(8) lobe [lEUb] n.圆形突出部（尤指耳垂）
(9) saliva [sE`laiv[] n.口水, 唾液
(10) permanently [ `p[:mEnEntli] adv.永存地, 不变地